[PATCH 00/10] NR_CPUS: third reduction of NR_CPUS memory usage x86-version v2

[PATCH 00/10] NR_CPUS: third reduction of NR_CPUS memory usage x86-version v2

[Mike Travis]

Wii, isn't this fun...!  This is a resubmission of yesterday's patches
based on the x86.git/latest tree.  Yes, it _is_ a maze of twisty litle
passages. ;-)  

Patches that are actually different are marked "v2". (I did not recalculate
the memory usages changes but I did reverify the defconfig and akpm2
configs with both 255 and 4096 NR_CPUS.)
...................

Here's the third round of removing static allocations of arrays using
NR_CPUS to size the length.  The change is to use PER_CPU variables in
place of the static tables, or allocate the array based on nr_cpu_ids.

In addition, there's a cleanup of x86 non-smp code, the movement of
setting nr_cpu_ids to setup_per_cpu_areas() so it's available as soon
as possible, and a new function cpumask_scnprintf_len() to return the
number of characters needed to display "len" cpumask bits.

Affected files:

	arch/ia64/kernel/acpi.c
	arch/ia64/kernel/setup.c
	arch/powerpc/kernel/setup_64.c
	arch/sparc64/mm/init.c
	arch/x86/kernel/cpu/intel_cacheinfo.c
	arch/x86/kernel/genapic_64.c
	arch/x86/kernel/mpparse_64.c
	arch/x86/kernel/setup64.c
	arch/x86/kernel/smpboot_32.c
	arch/x86/mm/numa_64.c
	arch/x86/oprofile/nmi_int.c
	drivers/acpi/processor_core.c
	drivers/acpi/processor_idle.c
	drivers/acpi/processor_perflib.c
	drivers/acpi/processor_throttling.c
	drivers/base/cpu.c
	drivers/cpufreq/cpufreq.c
	drivers/cpufreq/cpufreq_stats.c
	drivers/cpufreq/freq_table.c
	include/acpi/processor.h
	include/asm-x86/smp_32.h
	include/asm-x86/smp_64.h
	include/asm-x86/topology.h
	include/linux/bitmap.h
	include/linux/cpumask.h
	init/main.c
	kernel/sched.c
	lib/bitmap.c
	net/core/dev.c

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
	git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git


Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Andi Kleen <ak@suse.de>
Cc: Anton Blanchard <anton@samba.org>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: David S. Miller <davem@davemloft.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Paul Jackson <pj@sgi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Philippe Elie <phil.el@wanadoo.fr>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: William L. Irwin <wli@holomorphy.com>

Signed-off-by: Mike Travis <travis@sgi.com>
---

I moved the x86_64 cleanup and move-set-nr_cpu_ids from the zero-based
percpu variables patchset to this one, as I was encountering a panic
from system_call_after_swapgs() after an unknown device interrupt during
module loading.  That problem will be dealt with in another patch.


Here's the various effects of the patches on memory usages using the
akpm2 config file with NR_CPUS=4096 and MAXNODES=512:

====== Data (-l 500)
    1 - initial
    2 - cleanup
    4 - nr_cpus-in-cpufreq-cpu_alloc
    5 - nr_cpus-in-acpi-driver-cpu_alloc
    7 - nr_cpus-in-intel_cacheinfo
    8 - nr_cpus-in-cpu_c
   11 - nr_cpus-in-kernel_sched

    .1.   .2.     .4.     .5.   .7.     .8.    .11.  
  32768     .  -32768       .     .       .       .   show_table(.bss)
  32768     .       .       .     .       .  -32768   sched_group_nodes_bycpu(.bss)
  32768     .       .  -32768     .       .       .   processors(.bss)
  32768     .       .  -32768     .       .       .   processor_device_array(.bss)
  32768     .       .       .     .       .  -32768   init_sched_entity_p(.bss)
  32768     .       .       .     .       .  -32768   init_cfs_rq_p(.bss)
  32768     .       .       .-32768       .       .   index_kobject(.bss)
  32768     .       .       .-32768       .       .   cpuid4_info(.bss)
  32768     .  -32768       .     .       .       .   cpufreq_cpu_governor(.bss)
  32768     .  -32768       .     .       .       .   cpufreq_cpu_data(.bss)
  32768     .       .       .     .  -32768       .   cpu_sys_devices(.bss)
  32768     .       .       .-32768       .       .   cache_kobject(.bss)

====== Text/Data ()
    1 - initial
    4 - nr_cpus-in-cpufreq-cpu_alloc
    5 - nr_cpus-in-acpi-driver-cpu_alloc
    7 - nr_cpus-in-intel_cacheinfo
    8 - nr_cpus-in-cpu_c
   11 - nr_cpus-in-kernel_sched

       .1.     .4.     .5.     .7.     .8.    .11.    ..final..
   3373056       .   +2048       .       .       . 3375104    <1%  TextSize
   1656832       .   +2048       .       .       . 1658880    <1%  DataSize
   1855488  -98304  -65536  -98304  -32768  -98304 1462272   -21%  BssSize
  10395648       .   +4096       .       .       . 10399744   <1%  OtherSize
  17281024  -98304  -57344  -98304  -32768  -98304 16896000   -2%  Totals

====== Stack (-l 500)
... files 11 vars 928 all 0 lim 500 unch 0

    1 - initial
    7 - nr_cpus-in-intel_cacheinfo
   11 - nr_cpus-in-kernel_sched

   .1.    .7.   .11.    ..final..
  4648      .  -4080  568   -87%  cpu_attach_domain
  4104  -4104      .    .  -100%  show_shared_cpu_map
  8752  -4104  -4080  568   -93%  Totals

-- 

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[PATCH 01/10] x86_64: Cleanup non-smp usage of cpu maps v2

[Mike Travis]

[-- Attachment #1: cleanup --]
[-- Type: text/plain, Size: 6609 bytes --]

Cleanup references to the early cpu maps for the non-SMP configuration
and remove some functions called for SMP configurations only.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
	git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git

Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Christoph Lameter <clameter@sgi.com>

Signed-off-by: Mike Travis <travis@sgi.com>
---
This patch was moved from the zero-based percpu variables patchset to here.

v2: rebased on linux-2.6.git + linux-2.6-x86.git
---

 arch/x86/kernel/genapic_64.c |    2 ++
 arch/x86/kernel/mpparse_64.c |    2 ++
 arch/x86/kernel/setup.c      |   28 +++++++++++-----------------
 arch/x86/mm/numa_64.c        |    4 +++-
 include/asm-x86/smp.h        |    5 +++++
 include/asm-x86/topology.h   |   15 +++++++++++----
 6 files changed, 34 insertions(+), 22 deletions(-)

--- linux.trees.git.orig/arch/x86/kernel/genapic_64.c
+++ linux.trees.git/arch/x86/kernel/genapic_64.c
@@ -25,9 +25,11 @@
 #endif
 
 /* which logical CPU number maps to which CPU (physical APIC ID) */
+#ifdef CONFIG_SMP
 u16 x86_cpu_to_apicid_init[NR_CPUS] __initdata
 					= { [0 ... NR_CPUS-1] = BAD_APICID };
 void *x86_cpu_to_apicid_early_ptr;
+#endif
 DEFINE_PER_CPU(u16, x86_cpu_to_apicid) = BAD_APICID;
 EXPORT_PER_CPU_SYMBOL(x86_cpu_to_apicid);
 
--- linux.trees.git.orig/arch/x86/kernel/mpparse_64.c
+++ linux.trees.git/arch/x86/kernel/mpparse_64.c
@@ -69,9 +69,11 @@ unsigned disabled_cpus __cpuinitdata;
 /* Bitmask of physically existing CPUs */
 physid_mask_t phys_cpu_present_map = PHYSID_MASK_NONE;
 
+#ifdef CONFIG_SMP
 u16 x86_bios_cpu_apicid_init[NR_CPUS] __initdata
     = {[0 ... NR_CPUS - 1] = BAD_APICID };
 void *x86_bios_cpu_apicid_early_ptr;
+#endif
 DEFINE_PER_CPU(u16, x86_bios_cpu_apicid) = BAD_APICID;
 EXPORT_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
 
--- linux.trees.git.orig/arch/x86/kernel/setup.c
+++ linux.trees.git/arch/x86/kernel/setup.c
@@ -10,7 +10,7 @@
 #include <asm/setup.h>
 #include <asm/topology.h>
 
-#ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
+#if defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) && defined(CONFIG_SMP)
 /*
  * Copy data used in early init routines from the initial arrays to the
  * per cpu data areas.  These arrays then become expendable and the
@@ -21,22 +21,13 @@ static void __init setup_per_cpu_maps(vo
 	int cpu;
 
 	for_each_possible_cpu(cpu) {
-#ifdef CONFIG_SMP
-		if (per_cpu_offset(cpu)) {
-#endif
-			per_cpu(x86_cpu_to_apicid, cpu) =
-						x86_cpu_to_apicid_init[cpu];
-			per_cpu(x86_bios_cpu_apicid, cpu) =
+		per_cpu(x86_cpu_to_apicid, cpu) = x86_cpu_to_apicid_init[cpu];
+		per_cpu(x86_bios_cpu_apicid, cpu) =
 						x86_bios_cpu_apicid_init[cpu];
 #ifdef CONFIG_NUMA
-			per_cpu(x86_cpu_to_node_map, cpu) =
+		per_cpu(x86_cpu_to_node_map, cpu) =
 						x86_cpu_to_node_map_init[cpu];
 #endif
-#ifdef CONFIG_SMP
-		} else
-			printk(KERN_NOTICE "per_cpu_offset zero for cpu %d\n",
-									cpu);
-#endif
 	}
 
 	/* indicate the early static arrays will soon be gone */
@@ -72,17 +63,20 @@ void __init setup_per_cpu_areas(void)
 
 	/* Copy section for each CPU (we discard the original) */
 	size = PERCPU_ENOUGH_ROOM;
-
 	printk(KERN_INFO "PERCPU: Allocating %lu bytes of per cpu data\n",
 			  size);
-	for_each_cpu_mask(i, cpu_possible_map) {
+
+	for_each_possible_cpu(i) {
 		char *ptr;
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 		ptr = alloc_bootmem_pages(size);
 #else
 		int node = early_cpu_to_node(i);
-		if (!node_online(node) || !NODE_DATA(node))
+		if (!node_online(node) || !NODE_DATA(node)) {
 			ptr = alloc_bootmem_pages(size);
+			printk(KERN_INFO
+			       "cpu %d has no node or node-local memory\n", i);
+		}
 		else
 			ptr = alloc_bootmem_pages_node(NODE_DATA(node), size);
 #endif
@@ -96,7 +90,7 @@ void __init setup_per_cpu_areas(void)
 		memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
 	}
 
-	/* setup percpu data maps early */
+	/* Setup percpu data maps */
 	setup_per_cpu_maps();
 }
 
--- linux.trees.git.orig/arch/x86/mm/numa_64.c
+++ linux.trees.git/arch/x86/mm/numa_64.c
@@ -31,13 +31,15 @@ bootmem_data_t plat_node_bdata[MAX_NUMNO
 
 struct memnode memnode;
 
+#ifdef CONFIG_SMP
 int x86_cpu_to_node_map_init[NR_CPUS] = {
 	[0 ... NR_CPUS-1] = NUMA_NO_NODE
 };
 void *x86_cpu_to_node_map_early_ptr;
+EXPORT_SYMBOL(x86_cpu_to_node_map_early_ptr);
+#endif
 DEFINE_PER_CPU(int, x86_cpu_to_node_map) = NUMA_NO_NODE;
 EXPORT_PER_CPU_SYMBOL(x86_cpu_to_node_map);
-EXPORT_SYMBOL(x86_cpu_to_node_map_early_ptr);
 
 s16 apicid_to_node[MAX_LOCAL_APIC] __cpuinitdata = {
 	[0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
--- linux.trees.git.orig/include/asm-x86/smp.h
+++ linux.trees.git/include/asm-x86/smp.h
@@ -11,10 +11,15 @@ extern int smp_num_siblings;
 extern unsigned int num_processors;
 extern cpumask_t cpu_initialized;
 
+#ifdef CONFIG_SMP
 extern u16 x86_cpu_to_apicid_init[];
 extern u16 x86_bios_cpu_apicid_init[];
 extern void *x86_cpu_to_apicid_early_ptr;
 extern void *x86_bios_cpu_apicid_early_ptr;
+#else
+#define x86_cpu_to_apicid_early_ptr NULL
+#define x86_bios_cpu_apicid_early_ptr NULL
+#endif
 
 DECLARE_PER_CPU(cpumask_t, cpu_sibling_map);
 DECLARE_PER_CPU(cpumask_t, cpu_core_map);
--- linux.trees.git.orig/include/asm-x86/topology.h
+++ linux.trees.git/include/asm-x86/topology.h
@@ -39,8 +39,13 @@ extern int cpu_to_node_map[];
 #endif
 
 DECLARE_PER_CPU(int, x86_cpu_to_node_map);
+
+#ifdef CONFIG_SMP
 extern int x86_cpu_to_node_map_init[];
 extern void *x86_cpu_to_node_map_early_ptr;
+#else
+#define x86_cpu_to_node_map_early_ptr NULL
+#endif
 
 extern cpumask_t node_to_cpumask_map[];
 
@@ -55,6 +60,8 @@ static inline int cpu_to_node(int cpu)
 }
 
 #else /* CONFIG_X86_64 */
+
+#ifdef CONFIG_SMP
 static inline int early_cpu_to_node(int cpu)
 {
 	int *cpu_to_node_map = x86_cpu_to_node_map_early_ptr;
@@ -66,6 +73,9 @@ static inline int early_cpu_to_node(int 
 	else
 		return NUMA_NO_NODE;
 }
+#else
+#define	early_cpu_to_node(cpu)	cpu_to_node(cpu)
+#endif
 
 static inline int cpu_to_node(int cpu)
 {
@@ -77,10 +87,7 @@ static inline int cpu_to_node(int cpu)
 		return ((int *)x86_cpu_to_node_map_early_ptr)[cpu];
 	}
 #endif
-	if (per_cpu_offset(cpu))
-		return per_cpu(x86_cpu_to_node_map, cpu);
-	else
-		return NUMA_NO_NODE;
+	return per_cpu(x86_cpu_to_node_map, cpu);
 }
 #endif /* CONFIG_X86_64 */
 

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Re: [PATCH 01/10] x86_64: Cleanup non-smp usage of cpu maps v2

[Ingo Molnar]

* Mike Travis <travis@sgi.com> wrote:

> Cleanup references to the early cpu maps for the non-SMP configuration 
> and remove some functions called for SMP configurations only.

thanks, applied.

one observation:

> +#ifdef CONFIG_SMP
>  extern int x86_cpu_to_node_map_init[];
>  extern void *x86_cpu_to_node_map_early_ptr;
> +#else
> +#define x86_cpu_to_node_map_early_ptr NULL
> +#endif

Right now all these early_ptrs are in essence open-coded "early 
per-cpu", right? But shouldnt we solve that in a much cleaner way: by 
explicitly adding an early-per-cpu types and accessors, and avoid all 
that #ifdeffery?

	Ingo

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Re: [PATCH 01/10] x86_64: Cleanup non-smp usage of cpu maps v2

[Mike Travis]

Ingo Molnar wrote:
> * Mike Travis <travis@sgi.com> wrote:
> 
>> Cleanup references to the early cpu maps for the non-SMP configuration 
>> and remove some functions called for SMP configurations only.
> 
> thanks, applied.
> 
> one observation:
> 
>> +#ifdef CONFIG_SMP
>>  extern int x86_cpu_to_node_map_init[];
>>  extern void *x86_cpu_to_node_map_early_ptr;
>> +#else
>> +#define x86_cpu_to_node_map_early_ptr NULL
>> +#endif
> 
> Right now all these early_ptrs are in essence open-coded "early 
> per-cpu", right? But shouldnt we solve that in a much cleaner way: by 
> explicitly adding an early-per-cpu types and accessors, and avoid all 
> that #ifdeffery?
> 
> 	Ingo

I was thinking of something similar but had to put it on the back
burner until we got to the point of being able to boot a kernel
with NR_CPUS set to 4096.  It should pop back up on the priority
queue very soon... ;-)

Thanks!
Mike

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Re: [PATCH 01/10] x86_64: Cleanup non-smp usage of cpu maps v2

[Mike Travis]

Ingo Molnar wrote:
> * Mike Travis <travis@sgi.com> wrote:
> 
>> Cleanup references to the early cpu maps for the non-SMP configuration 
>> and remove some functions called for SMP configurations only.
> 
> thanks, applied.
> 
> one observation:
> 
>> +#ifdef CONFIG_SMP
>>  extern int x86_cpu_to_node_map_init[];
>>  extern void *x86_cpu_to_node_map_early_ptr;
>> +#else
>> +#define x86_cpu_to_node_map_early_ptr NULL
>> +#endif
> 
> Right now all these early_ptrs are in essence open-coded "early 
> per-cpu", right? But shouldnt we solve that in a much cleaner way: by 
> explicitly adding an early-per-cpu types and accessors, and avoid all 
> that #ifdeffery?
> 
> 	Ingo

How about something like the below? (I haven't tried compiling it yet.)

[I also thought about not restricting it to only NR_CPUS type variables
to allow for example, node-local node maps/variables.]

Thanks,
Mike
------------------------------------------------------------
include/linux/percpu.h:

#ifdef CONFIG_SMP
#define	DEFINE_EARLY_PER_CPU(type, name, initvalue)	\
	DEFINE_PER_CPU(type, name) = initvalue;		\
	type name##_early_map[NR_CPUS] __initdata =	\
		{ [0 ... NR_CPUS-1] = initvalue; }	\
	type *name##_early_ptr = name##_early_map

#define DECLARE_EARLY_PER_CPU(type, name)		\
	DECLARE_PER_CPU(type, name);			\
	extern type *name##_early_ptr;			\
	extern type  name##_early_map[]

#define EXPORT_EARLY_PER_CPU(name)			\
	EXPORT_PER_CPU(name)

/* rvalue only */
#define	early_per_cpu(name, cpu) 			\
	(name##ptr? name##ptr[cpu] : per_cpu(name, cpu))
#define	early_per_cpu_ptr(name) (name##_early_ptr)
#define	early_per_cpu_map(name, idx) (name##_early_map[idx])

#else	/* !CONFIG_SMP */
#define	DEFINE_EARLY_PER_CPU(type, name, initvalue)	\
	DEFINE_PER_CPU(type, name) = initvalue

#define DECLARE_EARLY_PER_CPU(name)			\
	DECLARE_PER_CPU(name)

#define EXPORT_EARLY_PER_CPU(name)			\
	EXPORT_PER_CPU(name)

#define	early_per_cpu(name, cpu) per_cpu(name, cpu) 
#define	early_per_cpu_ptr(name) NULL
/* no early_per_cpu_map() */

#endif	/* !CONFIG_SMP */


------------------------------------------------------------
include/asm-x86/smp.h:

DECLARE_EARLY_PER_CPU(u16, x86_cpu_to_apicid);
DECLARE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid);

------------------------------------------------------------
arch/x86/kernel/setup.c:

/* which logical CPU number maps to which CPU (physical APIC ID) */
DEFINE_EARLY_PER_CPU(u16, x86_cpu_to_apicid, BAD_APICID);
DEFINE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid, BAD_APICID);
EXPORT_EARLY_PER_CPU(x86_cpu_to_apicid);
EXPORT_EARLY_PER_CPU(x86_bios_cpu_apicid);

#ifdef CONFIG_NUMA
DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node, NUMA_NO_NODE);
EXPORT_EARLY_PER_CPU(x86_cpu_to_node);
#endif

...

#if defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) && defined(CONFIG_SMP)
/*
 * Copy data used in early init routines from the initial arrays to the
 * per cpu data areas.  These arrays then become expendable and the
 * *_early_ptr's are zeroed indicating that the static arrays are gone.
 */
static void __init setup_per_cpu_maps(void)
{
	int cpu;

	for_each_possible_cpu(cpu) {
		per_cpu(x86_cpu_to_apicid, cpu) =
				early_per_cpu_map(x86_cpu_to_apicid, cpu);
		per_cpu(x86_bios_cpu_apicid, cpu) =
				early_per_cpu_map(x86_bios_cpu_apicid, cpu);
#ifdef CONFIG_NUMA
		per_cpu(x86_cpu_to_node_map, cpu) =
				early_per_cpu_map(x86_cpu_to_node_map, cpu);
#endif
	}

	/* indicate the early static arrays will soon be gone */
	early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
	early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
#ifdef CONFIG_NUMA
	early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
#endif
	...

------------------------------------------------------------
arch/x86/mm/numa_64.c:

void __cpuinit numa_set_node(int cpu, int node)
{
	int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);

	if(cpu_to_node_map)
		cpu_to_node_map[cpu] = node;
	else if(per_cpu_offset(cpu))
		per_cpu(x86_cpu_to_node_map, cpu) = node;
...
void __init init_cpu_to_node(void)
{
	int i;

	for (i = 0; i < NR_CPUS; i++) {
		int node;
		u16 apicid = early_per_cpu(x86_cpu_to_apicid, i);

		if (apicid == BAD_APICID)
			continue;
...

------------------------------------------------------------

Re: [PATCH 01/10] x86_64: Cleanup non-smp usage of cpu maps v2

[Ingo Molnar]

* Mike Travis <travis@sgi.com> wrote:

> How about something like the below? (I haven't tried compiling it 
> yet.)

looks good to me - the closer it is to the real API, the better.

	Ingo

[PATCH 02/10] init: move setup of nr_cpu_ids to as early as possible v2

[Mike Travis]

[-- Attachment #1: setup-nr_cpu_ids --]
[-- Type: text/plain, Size: 6359 bytes --]

Move the setting of nr_cpu_ids from sched_init() to setup_per_cpu_areas(),
so that it's available as early as possible.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
	git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git

# ia64
Cc: Tony Luck <tony.luck@intel.com>

# powerpc
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anton Blanchard <anton@samba.org>

# sparc
Cc: David S. Miller <davem@davemloft.net>
Cc: William L. Irwin <wli@holomorphy.com>

# x86
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@zytor.com>

Signed-off-by: Mike Travis <travis@sgi.com>
---

Moved from the zero-based percpu variables patchset and redone to be
integrated with setup_per_cpu_areas instead of being called before
that function.  This had to be done because some arch's call
prefill_possible_map() from setup_per_cpu_areas() which may increase
the number of possible cpus.

v2: rebased on linux-2.6.git + linux-2.6-x86.git
---

 arch/ia64/kernel/acpi.c        |    4 ++++
 arch/ia64/kernel/setup.c       |    7 +++++++
 arch/powerpc/kernel/setup_64.c |    5 ++++-
 arch/sparc64/mm/init.c         |   10 +++++++++-
 arch/x86/kernel/setup.c        |   10 +++++++---
 init/main.c                    |   15 ++++++++++++---
 kernel/sched.c                 |    7 -------
 7 files changed, 43 insertions(+), 15 deletions(-)

--- linux.trees.git.orig/arch/ia64/kernel/acpi.c
+++ linux.trees.git/arch/ia64/kernel/acpi.c
@@ -831,6 +831,10 @@ __init void prefill_possible_map(void)
 
 	for (i = 0; i < possible; i++)
 		cpu_set(i, cpu_possible_map);
+
+#ifdef CONFIG_SMP
+	nr_cpu_ids = possible;
+#endif
 }
 
 int acpi_map_lsapic(acpi_handle handle, int *pcpu)
--- linux.trees.git.orig/arch/ia64/kernel/setup.c
+++ linux.trees.git/arch/ia64/kernel/setup.c
@@ -765,6 +765,13 @@ setup_per_cpu_areas (void)
 	/* start_kernel() requires this... */
 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 	prefill_possible_map();
+#elif defined(CONFIG_SMP)
+	int cpu, highest_cpu = 0;
+
+	for_each_possible_cpu(cpu)
+		highest_cpu = cpu;
+
+	nr_cpu_ids = highest_cpu + 1;
 #endif
 }
 
--- linux.trees.git.orig/arch/powerpc/kernel/setup_64.c
+++ linux.trees.git/arch/powerpc/kernel/setup_64.c
@@ -576,7 +576,7 @@ void cpu_die(void)
 #ifdef CONFIG_SMP
 void __init setup_per_cpu_areas(void)
 {
-	int i;
+	int i, highest_cpu = 0;
 	unsigned long size;
 	char *ptr;
 
@@ -594,7 +594,10 @@ void __init setup_per_cpu_areas(void)
 
 		paca[i].data_offset = ptr - __per_cpu_start;
 		memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
+		if (i > highest_cpu)
+			highest_cpu = i;
 	}
+	nr_cpu_ids = highest_cpu + 1;
 
 	/* Now that per_cpu is setup, initialize cpu_sibling_map */
 	smp_setup_cpu_sibling_map();
--- linux.trees.git.orig/arch/sparc64/mm/init.c
+++ linux.trees.git/arch/sparc64/mm/init.c
@@ -1292,10 +1292,18 @@ pgd_t swapper_pg_dir[2048];
 static void sun4u_pgprot_init(void);
 static void sun4v_pgprot_init(void);
 
-/* Dummy function */
+#ifdef CONFIG_SMP
+/* set nr_cpu_ids */
 void __init setup_per_cpu_areas(void)
 {
+	int cpu, highest_cpu = 0;
+
+	for_each_possible_cpu(cpu)
+		highest_cpu = cpu;
+
+	nr_cpu_ids = highest_cpu + 1;
 }
+#endif
 
 void __init paging_init(void)
 {
--- linux.trees.git.orig/arch/x86/kernel/setup.c
+++ linux.trees.git/arch/x86/kernel/setup.c
@@ -54,7 +54,7 @@ EXPORT_SYMBOL(__per_cpu_offset);
  */
 void __init setup_per_cpu_areas(void)
 {
-	int i;
+	int i, highest_cpu = 0;
 	unsigned long size;
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -80,15 +80,19 @@ void __init setup_per_cpu_areas(void)
 		else
 			ptr = alloc_bootmem_pages_node(NODE_DATA(node), size);
 #endif
-		if (!ptr)
-			panic("Cannot allocate cpu data for CPU %d\n", i);
+
 #ifdef CONFIG_X86_64
 		cpu_pda(i)->data_offset = ptr - __per_cpu_start;
 #else
 		__per_cpu_offset[i] = ptr - __per_cpu_start;
 #endif
 		memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
+
+		if (i > highest_cpu)
+			highest_cpu = i;
 	}
+	nr_cpu_ids = highest_cpu + 1;
+	printk(KERN_DEBUG "NR_CPUS:%d (nr_cpu_ids:%d)\n", NR_CPUS, nr_cpu_ids);
 
 	/* Setup percpu data maps */
 	setup_per_cpu_maps();
--- linux.trees.git.orig/init/main.c
+++ linux.trees.git/init/main.c
@@ -364,16 +364,20 @@ static inline void smp_prepare_cpus(unsi
 
 #else
 
+int nr_cpu_ids __read_mostly = NR_CPUS;
+EXPORT_SYMBOL(nr_cpu_ids);
+
 #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
-
 EXPORT_SYMBOL(__per_cpu_offset);
 
+/* nr_cpu_ids is set as a side effect */
 static void __init setup_per_cpu_areas(void)
 {
-	unsigned long size, i;
-	char *ptr;
+	unsigned long size;
+	int i, highest_cpu = 0;
 	unsigned long nr_possible_cpus = num_possible_cpus();
+	char *ptr;
 
 	/* Copy section for each CPU (we discard the original) */
 	size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
@@ -383,7 +387,12 @@ static void __init setup_per_cpu_areas(v
 		__per_cpu_offset[i] = ptr - __per_cpu_start;
 		memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
 		ptr += size;
+		if (i > highest_cpu)
+			highest_cpu = i;
 	}
+
+	nr_cpu_ids = highest_cpu + 1;
+	printk(KERN_DEBUG "NR_CPUS:%d (nr_cpu_ids:%d)\n", NR_CPUS, nr_cpu_ids);
 }
 #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
 
--- linux.trees.git.orig/kernel/sched.c
+++ linux.trees.git/kernel/sched.c
@@ -5923,10 +5923,6 @@ void __init migration_init(void)
 
 #ifdef CONFIG_SMP
 
-/* Number of possible processor ids */
-int nr_cpu_ids __read_mostly = NR_CPUS;
-EXPORT_SYMBOL(nr_cpu_ids);
-
 #ifdef CONFIG_SCHED_DEBUG
 
 static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level)
@@ -7152,7 +7148,6 @@ static void init_tg_rt_entry(struct rq *
 
 void __init sched_init(void)
 {
-	int highest_cpu = 0;
 	int i, j;
 
 #ifdef CONFIG_SMP
@@ -7207,7 +7202,6 @@ void __init sched_init(void)
 #endif
 		init_rq_hrtick(rq);
 		atomic_set(&rq->nr_iowait, 0);
-		highest_cpu = i;
 	}
 
 	set_load_weight(&init_task);
@@ -7217,7 +7211,6 @@ void __init sched_init(void)
 #endif
 
 #ifdef CONFIG_SMP
-	nr_cpu_ids = highest_cpu + 1;
 	open_softirq(SCHED_SOFTIRQ, run_rebalance_domains, NULL);
 #endif
 

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Re: [PATCH 02/10] init: move setup of nr_cpu_ids to as early as possible v2

[Ingo Molnar]

* Mike Travis <travis@sgi.com> wrote:

> Move the setting of nr_cpu_ids from sched_init() to 
> setup_per_cpu_areas(), so that it's available as early as possible.

hm, why not a separate call before setup_per_cpu_areas(), so that we can 
avoid spreading this from generic kernel into a bunch of architectures 
that happen to have their own version of setup_per_cpu_areas():

>  7 files changed, 43 insertions(+), 15 deletions(-)

	Ingo

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Re: [PATCH 02/10] init: move setup of nr_cpu_ids to as early as possible v2

[Mike Travis]

Ingo Molnar wrote:
> * Mike Travis <travis@sgi.com> wrote:
> 
>> Move the setting of nr_cpu_ids from sched_init() to 
>> setup_per_cpu_areas(), so that it's available as early as possible.
> 
> hm, why not a separate call before setup_per_cpu_areas(), so that we can 
> avoid spreading this from generic kernel into a bunch of architectures 
> that happen to have their own version of setup_per_cpu_areas():
> 
>>  7 files changed, 43 insertions(+), 15 deletions(-)
> 
> 	Ingo

I had this before but I then discovered that an arch would increase
(and possible decrease) it's number of possible cpus in setup_per_cpu_areas().
So I figured that setting nr_cpu_ids (and the cpumask_of_cpu map) should
be a side effect of setup_per_cpu_areas().

Thanks,
Mike

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Re: [PATCH 02/10] init: move setup of nr_cpu_ids to as early as possible v2

[Ingo Molnar]

* Mike Travis <travis@sgi.com> wrote:

> Ingo Molnar wrote:
> > * Mike Travis <travis@sgi.com> wrote:
> > 
> >> Move the setting of nr_cpu_ids from sched_init() to 
> >> setup_per_cpu_areas(), so that it's available as early as possible.
> > 
> > hm, why not a separate call before setup_per_cpu_areas(), so that we can 
> > avoid spreading this from generic kernel into a bunch of architectures 
> > that happen to have their own version of setup_per_cpu_areas():
> > 
> >>  7 files changed, 43 insertions(+), 15 deletions(-)
> > 
> > 	Ingo
> 
> I had this before but I then discovered that an arch would increase 
> (and possible decrease) it's number of possible cpus in 
> setup_per_cpu_areas(). So I figured that setting nr_cpu_ids (and the 
> cpumask_of_cpu map) should be a side effect of setup_per_cpu_areas().

well, then why not do it shortly after setup_per_cpu_areas()? That still 
moves it earlier than sched_init() but doesnt export all this code and 
complexity toevery setup_per_cpu_areas() implementation. (which clearly 
didnt need this complexity before)

	Ingo

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Re: [PATCH 02/10] init: move setup of nr_cpu_ids to as early as possible v2

[Mike Travis]

Ingo Molnar wrote:
> * Mike Travis <travis@sgi.com> wrote:
> 
>> Ingo Molnar wrote:
>>> * Mike Travis <travis@sgi.com> wrote:
>>>
>>>> Move the setting of nr_cpu_ids from sched_init() to 
>>>> setup_per_cpu_areas(), so that it's available as early as possible.
>>> hm, why not a separate call before setup_per_cpu_areas(), so that we can 
>>> avoid spreading this from generic kernel into a bunch of architectures 
>>> that happen to have their own version of setup_per_cpu_areas():
>>>
>>>>  7 files changed, 43 insertions(+), 15 deletions(-)
>>> 	Ingo
>> I had this before but I then discovered that an arch would increase 
>> (and possible decrease) it's number of possible cpus in 
>> setup_per_cpu_areas(). So I figured that setting nr_cpu_ids (and the 
>> cpumask_of_cpu map) should be a side effect of setup_per_cpu_areas().
> 
> well, then why not do it shortly after setup_per_cpu_areas()? That still 
> moves it earlier than sched_init() but doesnt export all this code and 
> complexity toevery setup_per_cpu_areas() implementation. (which clearly 
> didnt need this complexity before)
> 
> 	Ingo


Ok, will do.

Thanks,
Mike

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[PATCH 03/10] cpufreq: change cpu freq arrays to per_cpu variables

[Mike Travis]

[-- Attachment #1: nr_cpus-in-cpufreq-cpu_alloc --]
[-- Type: text/plain, Size: 11179 bytes --]

Change cpufreq_policy and cpufreq_governor pointer tables
from arrays to per_cpu variables in the cpufreq subsystem.

Also some minor complaints from checkpatch.pl fixed.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
	git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git

Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Mike Travis <travis@sgi.com>
---
 drivers/cpufreq/cpufreq.c       |   45 +++++++++++++++++++++-------------------
 drivers/cpufreq/cpufreq_stats.c |   24 ++++++++++-----------
 drivers/cpufreq/freq_table.c    |   12 +++++-----
 3 files changed, 42 insertions(+), 39 deletions(-)

--- linux.trees.git.orig/drivers/cpufreq/cpufreq.c
+++ linux.trees.git/drivers/cpufreq/cpufreq.c
@@ -38,10 +38,10 @@
  * also protects the cpufreq_cpu_data array.
  */
 static struct cpufreq_driver *cpufreq_driver;
-static struct cpufreq_policy *cpufreq_cpu_data[NR_CPUS];
+static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
 #ifdef CONFIG_HOTPLUG_CPU
 /* This one keeps track of the previously set governor of a removed CPU */
-static struct cpufreq_governor *cpufreq_cpu_governor[NR_CPUS];
+static DEFINE_PER_CPU(struct cpufreq_governor *, cpufreq_cpu_governor);
 #endif
 static DEFINE_SPINLOCK(cpufreq_driver_lock);
 
@@ -133,7 +133,7 @@ struct cpufreq_policy *cpufreq_cpu_get(u
 	struct cpufreq_policy *data;
 	unsigned long flags;
 
-	if (cpu >= NR_CPUS)
+	if (cpu >= nr_cpu_ids)
 		goto err_out;
 
 	/* get the cpufreq driver */
@@ -147,7 +147,7 @@ struct cpufreq_policy *cpufreq_cpu_get(u
 
 
 	/* get the CPU */
-	data = cpufreq_cpu_data[cpu];
+	data = per_cpu(cpufreq_cpu_data, cpu);
 
 	if (!data)
 		goto err_out_put_module;
@@ -325,7 +325,7 @@ void cpufreq_notify_transition(struct cp
 	dprintk("notification %u of frequency transition to %u kHz\n",
 		state, freqs->new);
 
-	policy = cpufreq_cpu_data[freqs->cpu];
+	policy = per_cpu(cpufreq_cpu_data, freqs->cpu);
 	switch (state) {
 
 	case CPUFREQ_PRECHANGE:
@@ -809,8 +809,8 @@ static int cpufreq_add_dev (struct sys_d
 #ifdef CONFIG_SMP
 
 #ifdef CONFIG_HOTPLUG_CPU
-	if (cpufreq_cpu_governor[cpu]){
-		policy->governor = cpufreq_cpu_governor[cpu];
+	if (per_cpu(cpufreq_cpu_governor, cpu)) {
+		policy->governor = per_cpu(cpufreq_cpu_governor, cpu);
 		dprintk("Restoring governor %s for cpu %d\n",
 		       policy->governor->name, cpu);
 	}
@@ -835,7 +835,7 @@ static int cpufreq_add_dev (struct sys_d
 
 			spin_lock_irqsave(&cpufreq_driver_lock, flags);
 			managed_policy->cpus = policy->cpus;
-			cpufreq_cpu_data[cpu] = managed_policy;
+			per_cpu(cpufreq_cpu_data, cpu) = managed_policy;
 			spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
 			dprintk("CPU already managed, adding link\n");
@@ -890,7 +890,7 @@ static int cpufreq_add_dev (struct sys_d
 
 	spin_lock_irqsave(&cpufreq_driver_lock, flags);
 	for_each_cpu_mask(j, policy->cpus) {
-		cpufreq_cpu_data[j] = policy;
+		per_cpu(cpufreq_cpu_data, j) = policy;
 		per_cpu(policy_cpu, j) = policy->cpu;
 	}
 	spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
@@ -939,7 +939,7 @@ static int cpufreq_add_dev (struct sys_d
 err_out_unregister:
 	spin_lock_irqsave(&cpufreq_driver_lock, flags);
 	for_each_cpu_mask(j, policy->cpus)
-		cpufreq_cpu_data[j] = NULL;
+		per_cpu(cpufreq_cpu_data, j) = NULL;
 	spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
 	kobject_put(&policy->kobj);
@@ -981,7 +981,7 @@ static int __cpufreq_remove_dev (struct 
 	dprintk("unregistering CPU %u\n", cpu);
 
 	spin_lock_irqsave(&cpufreq_driver_lock, flags);
-	data = cpufreq_cpu_data[cpu];
+	data = per_cpu(cpufreq_cpu_data, cpu);
 
 	if (!data) {
 		spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
@@ -989,7 +989,7 @@ static int __cpufreq_remove_dev (struct 
 		unlock_policy_rwsem_write(cpu);
 		return -EINVAL;
 	}
-	cpufreq_cpu_data[cpu] = NULL;
+	per_cpu(cpufreq_cpu_data, cpu) = NULL;
 
 
 #ifdef CONFIG_SMP
@@ -1011,19 +1011,19 @@ static int __cpufreq_remove_dev (struct 
 #ifdef CONFIG_SMP
 
 #ifdef CONFIG_HOTPLUG_CPU
-	cpufreq_cpu_governor[cpu] = data->governor;
+	per_cpu(cpufreq_cpu_governor, cpu) = data->governor;
 #endif
 
 	/* if we have other CPUs still registered, we need to unlink them,
 	 * or else wait_for_completion below will lock up. Clean the
-	 * cpufreq_cpu_data[] while holding the lock, and remove the sysfs
-	 * links afterwards.
+	 * per_cpu(cpufreq_cpu_data) while holding the lock, and remove
+	 * the sysfs links afterwards.
 	 */
 	if (unlikely(cpus_weight(data->cpus) > 1)) {
 		for_each_cpu_mask(j, data->cpus) {
 			if (j == cpu)
 				continue;
-			cpufreq_cpu_data[j] = NULL;
+			per_cpu(cpufreq_cpu_data, j) = NULL;
 		}
 	}
 
@@ -1035,7 +1035,7 @@ static int __cpufreq_remove_dev (struct 
 				continue;
 			dprintk("removing link for cpu %u\n", j);
 #ifdef CONFIG_HOTPLUG_CPU
-			cpufreq_cpu_governor[j] = data->governor;
+			per_cpu(cpufreq_cpu_governor, j) = data->governor;
 #endif
 			cpu_sys_dev = get_cpu_sysdev(j);
 			sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq");
@@ -1145,7 +1145,7 @@ EXPORT_SYMBOL(cpufreq_quick_get);
 
 static unsigned int __cpufreq_get(unsigned int cpu)
 {
-	struct cpufreq_policy *policy = cpufreq_cpu_data[cpu];
+	struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
 	unsigned int ret_freq = 0;
 
 	if (!cpufreq_driver->get)
@@ -1818,16 +1818,19 @@ int cpufreq_register_driver(struct cpufr
 	cpufreq_driver = driver_data;
 	spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
-	ret = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver);
+	ret = sysdev_driver_register(&cpu_sysdev_class,
+					&cpufreq_sysdev_driver);
 
 	if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) {
 		int i;
 		ret = -ENODEV;
 
 		/* check for at least one working CPU */
-		for (i=0; i<NR_CPUS; i++)
-			if (cpufreq_cpu_data[i])
+		for (i = 0; i < nr_cpu_ids; i++)
+			if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) {
 				ret = 0;
+				break;
+			}
 
 		/* if all ->init() calls failed, unregister */
 		if (ret) {
--- linux.trees.git.orig/drivers/cpufreq/cpufreq_stats.c
+++ linux.trees.git/drivers/cpufreq/cpufreq_stats.c
@@ -43,7 +43,7 @@ struct cpufreq_stats {
 #endif
 };
 
-static struct cpufreq_stats *cpufreq_stats_table[NR_CPUS];
+static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);
 
 struct cpufreq_stats_attribute {
 	struct attribute attr;
@@ -58,7 +58,7 @@ cpufreq_stats_update (unsigned int cpu)
 
 	cur_time = get_jiffies_64();
 	spin_lock(&cpufreq_stats_lock);
-	stat = cpufreq_stats_table[cpu];
+	stat = per_cpu(cpufreq_stats_table, cpu);
 	if (stat->time_in_state)
 		stat->time_in_state[stat->last_index] =
 			cputime64_add(stat->time_in_state[stat->last_index],
@@ -71,11 +71,11 @@ cpufreq_stats_update (unsigned int cpu)
 static ssize_t
 show_total_trans(struct cpufreq_policy *policy, char *buf)
 {
-	struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
+	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
 	if (!stat)
 		return 0;
 	return sprintf(buf, "%d\n",
-			cpufreq_stats_table[stat->cpu]->total_trans);
+			per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
 }
 
 static ssize_t
@@ -83,7 +83,7 @@ show_time_in_state(struct cpufreq_policy
 {
 	ssize_t len = 0;
 	int i;
-	struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
+	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
 	if (!stat)
 		return 0;
 	cpufreq_stats_update(stat->cpu);
@@ -101,7 +101,7 @@ show_trans_table(struct cpufreq_policy *
 	ssize_t len = 0;
 	int i, j;
 
-	struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
+	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
 	if (!stat)
 		return 0;
 	cpufreq_stats_update(stat->cpu);
@@ -166,7 +166,7 @@ freq_table_get_index(struct cpufreq_stat
 
 static void cpufreq_stats_free_table(unsigned int cpu)
 {
-	struct cpufreq_stats *stat = cpufreq_stats_table[cpu];
+	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
 	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
 	if (policy && policy->cpu == cpu)
 		sysfs_remove_group(&policy->kobj, &stats_attr_group);
@@ -174,7 +174,7 @@ static void cpufreq_stats_free_table(uns
 		kfree(stat->time_in_state);
 		kfree(stat);
 	}
-	cpufreq_stats_table[cpu] = NULL;
+	per_cpu(cpufreq_stats_table, cpu) = NULL;
 	if (policy)
 		cpufreq_cpu_put(policy);
 }
@@ -188,7 +188,7 @@ cpufreq_stats_create_table (struct cpufr
 	struct cpufreq_policy *data;
 	unsigned int alloc_size;
 	unsigned int cpu = policy->cpu;
-	if (cpufreq_stats_table[cpu])
+	if (per_cpu(cpufreq_stats_table, cpu))
 		return -EBUSY;
 	if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
 		return -ENOMEM;
@@ -203,7 +203,7 @@ cpufreq_stats_create_table (struct cpufr
 		goto error_out;
 
 	stat->cpu = cpu;
-	cpufreq_stats_table[cpu] = stat;
+	per_cpu(cpufreq_stats_table, cpu) = stat;
 
 	for (i=0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
 		unsigned int freq = table[i].frequency;
@@ -247,7 +247,7 @@ error_out:
 	cpufreq_cpu_put(data);
 error_get_fail:
 	kfree(stat);
-	cpufreq_stats_table[cpu] = NULL;
+	per_cpu(cpufreq_stats_table, cpu) = NULL;
 	return ret;
 }
 
@@ -280,7 +280,7 @@ cpufreq_stat_notifier_trans (struct noti
 	if (val != CPUFREQ_POSTCHANGE)
 		return 0;
 
-	stat = cpufreq_stats_table[freq->cpu];
+	stat = per_cpu(cpufreq_stats_table, freq->cpu);
 	if (!stat)
 		return 0;
 
--- linux.trees.git.orig/drivers/cpufreq/freq_table.c
+++ linux.trees.git/drivers/cpufreq/freq_table.c
@@ -169,7 +169,7 @@ int cpufreq_frequency_table_target(struc
 }
 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);
 
-static struct cpufreq_frequency_table *show_table[NR_CPUS];
+static DEFINE_PER_CPU(struct cpufreq_frequency_table *, show_table);
 /**
  * show_available_freqs - show available frequencies for the specified CPU
  */
@@ -180,10 +180,10 @@ static ssize_t show_available_freqs (str
 	ssize_t count = 0;
 	struct cpufreq_frequency_table *table;
 
-	if (!show_table[cpu])
+	if (!per_cpu(show_table, cpu))
 		return -ENODEV;
 
-	table = show_table[cpu];
+	table = per_cpu(show_table, cpu);
 
 	for (i=0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
 		if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
@@ -212,20 +212,20 @@ void cpufreq_frequency_table_get_attr(st
 				      unsigned int cpu)
 {
 	dprintk("setting show_table for cpu %u to %p\n", cpu, table);
-	show_table[cpu] = table;
+	per_cpu(show_table, cpu) = table;
 }
 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_attr);
 
 void cpufreq_frequency_table_put_attr(unsigned int cpu)
 {
 	dprintk("clearing show_table for cpu %u\n", cpu);
-	show_table[cpu] = NULL;
+	per_cpu(show_table, cpu) = NULL;
 }
 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_put_attr);
 
 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
 {
-	return show_table[cpu];
+	return per_cpu(show_table, cpu);
 }
 EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);
 

-- 

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[PATCH 04/10] acpi: change processors from array to per_cpu variable

[Mike Travis]

[-- Attachment #1: nr_cpus-in-acpi-driver-cpu_alloc --]
[-- Type: text/plain, Size: 8204 bytes --]

Change processors from an array sized by NR_CPUS to a per_cpu variable.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
	git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git

Cc: Len Brown <len.brown@intel.com>
Signed-off-by: Mike Travis <travis@sgi.com>
---
 drivers/acpi/processor_core.c       |   18 ++++++++----------
 drivers/acpi/processor_idle.c       |    8 ++++----
 drivers/acpi/processor_perflib.c    |   18 +++++++++---------
 drivers/acpi/processor_throttling.c |   14 +++++++-------
 include/acpi/processor.h            |    2 +-
 5 files changed, 29 insertions(+), 31 deletions(-)

--- linux.trees.git.orig/drivers/acpi/processor_core.c
+++ linux.trees.git/drivers/acpi/processor_core.c
@@ -118,7 +118,7 @@ static const struct file_operations acpi
 	.release = single_release,
 };
 
-struct acpi_processor *processors[NR_CPUS];
+DEFINE_PER_CPU(struct acpi_processor *, processors);
 struct acpi_processor_errata errata __read_mostly;
 
 /* --------------------------------------------------------------------------
@@ -615,7 +615,7 @@ static int acpi_processor_get_info(struc
 	return 0;
 }
 
-static void *processor_device_array[NR_CPUS];
+static DEFINE_PER_CPU(void *, processor_device_array);
 
 static int __cpuinit acpi_processor_start(struct acpi_device *device)
 {
@@ -639,15 +639,15 @@ static int __cpuinit acpi_processor_star
 	 * ACPI id of processors can be reported wrongly by the BIOS.
 	 * Don't trust it blindly
 	 */
-	if (processor_device_array[pr->id] != NULL &&
-	    processor_device_array[pr->id] != device) {
+	if (per_cpu(processor_device_array, pr->id) != NULL &&
+	    per_cpu(processor_device_array, pr->id) != device) {
 		printk(KERN_WARNING "BIOS reported wrong ACPI id "
 			"for the processor\n");
 		return -ENODEV;
 	}
-	processor_device_array[pr->id] = device;
+	per_cpu(processor_device_array, pr->id) = device;
 
-	processors[pr->id] = pr;
+	per_cpu(processors, pr->id) = pr;
 
 	result = acpi_processor_add_fs(device);
 	if (result)
@@ -751,7 +751,7 @@ static int acpi_cpu_soft_notify(struct n
 		unsigned long action, void *hcpu)
 {
 	unsigned int cpu = (unsigned long)hcpu;
-	struct acpi_processor *pr = processors[cpu];
+	struct acpi_processor *pr = per_cpu(processors, cpu);
 
 	if (action == CPU_ONLINE && pr) {
 		acpi_processor_ppc_has_changed(pr);
@@ -821,7 +821,7 @@ static int acpi_processor_remove(struct 
 		pr->cdev = NULL;
 	}
 
-	processors[pr->id] = NULL;
+	per_cpu(processors, pr->id) = NULL;
 
 	kfree(pr);
 
@@ -1070,8 +1070,6 @@ static int __init acpi_processor_init(vo
 {
 	int result = 0;
 
-
-	memset(&processors, 0, sizeof(processors));
 	memset(&errata, 0, sizeof(errata));
 
 #ifdef CONFIG_SMP
--- linux.trees.git.orig/drivers/acpi/processor_idle.c
+++ linux.trees.git/drivers/acpi/processor_idle.c
@@ -401,7 +401,7 @@ static void acpi_processor_idle(void)
 	 */
 	local_irq_disable();
 
-	pr = processors[smp_processor_id()];
+	pr = __get_cpu_var(processors);
 	if (!pr) {
 		local_irq_enable();
 		return;
@@ -1425,7 +1425,7 @@ static int acpi_idle_enter_c1(struct cpu
 	struct acpi_processor *pr;
 	struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 
-	pr = processors[smp_processor_id()];
+	pr = __get_cpu_var(processors);
 
 	if (unlikely(!pr))
 		return 0;
@@ -1465,7 +1465,7 @@ static int acpi_idle_enter_simple(struct
 	u32 t1, t2;
 	int sleep_ticks = 0;
 
-	pr = processors[smp_processor_id()];
+	pr = __get_cpu_var(processors);
 
 	if (unlikely(!pr))
 		return 0;
@@ -1544,7 +1544,7 @@ static int acpi_idle_enter_bm(struct cpu
 	u32 t1, t2;
 	int sleep_ticks = 0;
 
-	pr = processors[smp_processor_id()];
+	pr = __get_cpu_var(processors);
 
 	if (unlikely(!pr))
 		return 0;
--- linux.trees.git.orig/drivers/acpi/processor_perflib.c
+++ linux.trees.git/drivers/acpi/processor_perflib.c
@@ -89,7 +89,7 @@ static int acpi_processor_ppc_notifier(s
 	if (event != CPUFREQ_INCOMPATIBLE)
 		goto out;
 
-	pr = processors[policy->cpu];
+	pr = per_cpu(processors, policy->cpu);
 	if (!pr || !pr->performance)
 		goto out;
 
@@ -577,7 +577,7 @@ int acpi_processor_preregister_performan
 
 	/* Call _PSD for all CPUs */
 	for_each_possible_cpu(i) {
-		pr = processors[i];
+		pr = per_cpu(processors, i);
 		if (!pr) {
 			/* Look only at processors in ACPI namespace */
 			continue;
@@ -608,7 +608,7 @@ int acpi_processor_preregister_performan
 	 * domain info.
 	 */
 	for_each_possible_cpu(i) {
-		pr = processors[i];
+		pr = per_cpu(processors, i);
 		if (!pr)
 			continue;
 
@@ -629,7 +629,7 @@ int acpi_processor_preregister_performan
 
 	cpus_clear(covered_cpus);
 	for_each_possible_cpu(i) {
-		pr = processors[i];
+		pr = per_cpu(processors, i);
 		if (!pr)
 			continue;
 
@@ -656,7 +656,7 @@ int acpi_processor_preregister_performan
 			if (i == j)
 				continue;
 
-			match_pr = processors[j];
+			match_pr = per_cpu(processors, j);
 			if (!match_pr)
 				continue;
 
@@ -685,7 +685,7 @@ int acpi_processor_preregister_performan
 			if (i == j)
 				continue;
 
-			match_pr = processors[j];
+			match_pr = per_cpu(processors, j);
 			if (!match_pr)
 				continue;
 
@@ -702,7 +702,7 @@ int acpi_processor_preregister_performan
 
 err_ret:
 	for_each_possible_cpu(i) {
-		pr = processors[i];
+		pr = per_cpu(processors, i);
 		if (!pr || !pr->performance)
 			continue;
 
@@ -733,7 +733,7 @@ acpi_processor_register_performance(stru
 
 	mutex_lock(&performance_mutex);
 
-	pr = processors[cpu];
+	pr = per_cpu(processors, cpu);
 	if (!pr) {
 		mutex_unlock(&performance_mutex);
 		return -ENODEV;
@@ -771,7 +771,7 @@ acpi_processor_unregister_performance(st
 
 	mutex_lock(&performance_mutex);
 
-	pr = processors[cpu];
+	pr = per_cpu(processors, cpu);
 	if (!pr) {
 		mutex_unlock(&performance_mutex);
 		return;
--- linux.trees.git.orig/drivers/acpi/processor_throttling.c
+++ linux.trees.git/drivers/acpi/processor_throttling.c
@@ -71,7 +71,7 @@ static int acpi_processor_update_tsd_coo
 	 * coordination between all CPUs.
 	 */
 	for_each_possible_cpu(i) {
-		pr = processors[i];
+		pr = per_cpu(processors, i);
 		if (!pr)
 			continue;
 
@@ -93,7 +93,7 @@ static int acpi_processor_update_tsd_coo
 
 	cpus_clear(covered_cpus);
 	for_each_possible_cpu(i) {
-		pr = processors[i];
+		pr = per_cpu(processors, i);
 		if (!pr)
 			continue;
 
@@ -119,7 +119,7 @@ static int acpi_processor_update_tsd_coo
 			if (i == j)
 				continue;
 
-			match_pr = processors[j];
+			match_pr = per_cpu(processors, j);
 			if (!match_pr)
 				continue;
 
@@ -152,7 +152,7 @@ static int acpi_processor_update_tsd_coo
 			if (i == j)
 				continue;
 
-			match_pr = processors[j];
+			match_pr = per_cpu(processors, j);
 			if (!match_pr)
 				continue;
 
@@ -172,7 +172,7 @@ static int acpi_processor_update_tsd_coo
 
 err_ret:
 	for_each_possible_cpu(i) {
-		pr = processors[i];
+		pr = per_cpu(processors, i);
 		if (!pr)
 			continue;
 
@@ -214,7 +214,7 @@ static int acpi_processor_throttling_not
 	struct acpi_processor_throttling *p_throttling;
 
 	cpu = p_tstate->cpu;
-	pr = processors[cpu];
+	pr = per_cpu(processors, cpu);
 	if (!pr) {
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid pr pointer\n"));
 		return 0;
@@ -1035,7 +1035,7 @@ int acpi_processor_set_throttling(struct
 		 * cpus.
 		 */
 		for_each_cpu_mask(i, online_throttling_cpus) {
-			match_pr = processors[i];
+			match_pr = per_cpu(processors, i);
 			/*
 			 * If the pointer is invalid, we will report the
 			 * error message and continue.
--- linux.trees.git.orig/include/acpi/processor.h
+++ linux.trees.git/include/acpi/processor.h
@@ -255,7 +255,7 @@ extern void acpi_processor_unregister_pe
 int acpi_processor_notify_smm(struct module *calling_module);
 
 /* for communication between multiple parts of the processor kernel module */
-extern struct acpi_processor *processors[NR_CPUS];
+DECLARE_PER_CPU(struct acpi_processor *, processors);
 extern struct acpi_processor_errata errata;
 
 void arch_acpi_processor_init_pdc(struct acpi_processor *pr);

-- 

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[PATCH 05/10] cpumask: Add cpumask_scnprintf_len function

[Mike Travis]

[-- Attachment #1: add-cpumask_scnprintf_len --]
[-- Type: text/plain, Size: 2896 bytes --]

Add a new function cpumask_scnprintf_len() to return the number of
characters needed to display "len" cpumask bits.  The current method
of allocating NR_CPUS bytes is incorrect as what's really needed is
9 characters per 32-bit word of cpumask bits (8 hex digits plus the
seperator [','] or the terminating NULL.)  This function provides the
caller the means to allocate the correct string length.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
	git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git

Cc: Paul Jackson <pj@sgi.com>

Signed-off-by: Mike Travis <travis@sgi.com>
---
 include/linux/bitmap.h  |    1 +
 include/linux/cpumask.h |    7 +++++++
 lib/bitmap.c            |   16 ++++++++++++++++
 3 files changed, 24 insertions(+)

--- linux.trees.git.orig/include/linux/bitmap.h
+++ linux.trees.git/include/linux/bitmap.h
@@ -108,6 +108,7 @@ extern int __bitmap_weight(const unsigne
 
 extern int bitmap_scnprintf(char *buf, unsigned int len,
 			const unsigned long *src, int nbits);
+extern int bitmap_scnprintf_len(unsigned int len);
 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
 			unsigned long *dst, int nbits);
 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
--- linux.trees.git.orig/include/linux/cpumask.h
+++ linux.trees.git/include/linux/cpumask.h
@@ -273,6 +273,13 @@ static inline int __cpumask_scnprintf(ch
 	return bitmap_scnprintf(buf, len, srcp->bits, nbits);
 }
 
+#define cpumask_scnprintf_len(len) \
+			__cpumask_scnprintf_len((len))
+static inline int __cpumask_scnprintf_len(int len)
+{
+	return bitmap_scnprintf_len(len);
+}
+
 #define cpumask_parse_user(ubuf, ulen, dst) \
 			__cpumask_parse_user((ubuf), (ulen), &(dst), NR_CPUS)
 static inline int __cpumask_parse_user(const char __user *buf, int len,
--- linux.trees.git.orig/lib/bitmap.c
+++ linux.trees.git/lib/bitmap.c
@@ -316,6 +316,22 @@ int bitmap_scnprintf(char *buf, unsigned
 EXPORT_SYMBOL(bitmap_scnprintf);
 
 /**
+ * bitmap_scnprintf_len - return buffer length needed to convert
+ * bitmap to an ASCII hex string.
+ * @len: number of bits to be converted
+ */
+int bitmap_scnprintf_len(unsigned int len)
+{
+	/* we need 9 chars per word for 32 bit words (8 hexdigits + sep/null) */
+	int bitslen = ALIGN(len, CHUNKSZ);
+	int wordlen = CHUNKSZ / 4;
+	int buflen = (bitslen / wordlen) * (wordlen + 1) * sizeof(char);
+
+	return buflen;
+}
+EXPORT_SYMBOL(bitmap_scnprintf_len);
+
+/**
  * __bitmap_parse - convert an ASCII hex string into a bitmap.
  * @buf: pointer to buffer containing string.
  * @buflen: buffer size in bytes.  If string is smaller than this

-- 

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[PATCH 06/10] x86: reduce memory and stack usage in intel_cacheinfo

[Mike Travis]

[-- Attachment #1: nr_cpus-in-intel_cacheinfo --]
[-- Type: text/plain, Size: 7368 bytes --]

* Change the following static arrays sized by NR_CPUS to
  per_cpu data variables:

	_cpuid4_info *cpuid4_info[NR_CPUS];
	_index_kobject *index_kobject[NR_CPUS];
	kobject * cache_kobject[NR_CPUS];

* Remove the local NR_CPUS array with a kmalloc'd region in
  show_shared_cpu_map().

Also some minor complaints from checkpatch.pl fixed.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
	git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andi Kleen <ak@suse.de>

Signed-off-by: Mike Travis <travis@sgi.com>
---
 arch/x86/kernel/cpu/intel_cacheinfo.c |   70 +++++++++++++++++++---------------
 1 file changed, 40 insertions(+), 30 deletions(-)

--- linux.trees.git.orig/arch/x86/kernel/cpu/intel_cacheinfo.c
+++ linux.trees.git/arch/x86/kernel/cpu/intel_cacheinfo.c
@@ -129,7 +129,7 @@ struct _cpuid4_info {
 	union _cpuid4_leaf_ebx ebx;
 	union _cpuid4_leaf_ecx ecx;
 	unsigned long size;
-	cpumask_t shared_cpu_map;
+	cpumask_t shared_cpu_map;	/* future?: only cpus/node is needed */
 };
 
 unsigned short			num_cache_leaves;
@@ -451,8 +451,8 @@ unsigned int __cpuinit init_intel_cachei
 }
 
 /* pointer to _cpuid4_info array (for each cache leaf) */
-static struct _cpuid4_info *cpuid4_info[NR_CPUS];
-#define CPUID4_INFO_IDX(x,y)    (&((cpuid4_info[x])[y]))
+static DEFINE_PER_CPU(struct _cpuid4_info *, cpuid4_info);
+#define CPUID4_INFO_IDX(x, y)    (&((per_cpu(cpuid4_info, x))[y]))
 
 #ifdef CONFIG_SMP
 static void __cpuinit cache_shared_cpu_map_setup(unsigned int cpu, int index)
@@ -474,7 +474,7 @@ static void __cpuinit cache_shared_cpu_m
 			if (cpu_data(i).apicid >> index_msb ==
 			    c->apicid >> index_msb) {
 				cpu_set(i, this_leaf->shared_cpu_map);
-				if (i != cpu && cpuid4_info[i])  {
+				if (i != cpu && per_cpu(cpuid4_info, i))  {
 					sibling_leaf = CPUID4_INFO_IDX(i, index);
 					cpu_set(cpu, sibling_leaf->shared_cpu_map);
 				}
@@ -505,8 +505,8 @@ static void __cpuinit free_cache_attribu
 	for (i = 0; i < num_cache_leaves; i++)
 		cache_remove_shared_cpu_map(cpu, i);
 
-	kfree(cpuid4_info[cpu]);
-	cpuid4_info[cpu] = NULL;
+	kfree(per_cpu(cpuid4_info, cpu));
+	per_cpu(cpuid4_info, cpu) = NULL;
 }
 
 static int __cpuinit detect_cache_attributes(unsigned int cpu)
@@ -519,9 +519,9 @@ static int __cpuinit detect_cache_attrib
 	if (num_cache_leaves == 0)
 		return -ENOENT;
 
-	cpuid4_info[cpu] = kzalloc(
+	per_cpu(cpuid4_info, cpu) = kzalloc(
 	    sizeof(struct _cpuid4_info) * num_cache_leaves, GFP_KERNEL);
-	if (cpuid4_info[cpu] == NULL)
+	if (per_cpu(cpuid4_info, cpu) == NULL)
 		return -ENOMEM;
 
 	oldmask = current->cpus_allowed;
@@ -546,8 +546,8 @@ static int __cpuinit detect_cache_attrib
 
 out:
 	if (retval) {
-		kfree(cpuid4_info[cpu]);
-		cpuid4_info[cpu] = NULL;
+		kfree(per_cpu(cpuid4_info, cpu));
+		per_cpu(cpuid4_info, cpu) = NULL;
 	}
 
 	return retval;
@@ -561,7 +561,7 @@ out:
 extern struct sysdev_class cpu_sysdev_class; /* from drivers/base/cpu.c */
 
 /* pointer to kobject for cpuX/cache */
-static struct kobject * cache_kobject[NR_CPUS];
+static DEFINE_PER_CPU(struct kobject *, cache_kobject);
 
 struct _index_kobject {
 	struct kobject kobj;
@@ -570,8 +570,8 @@ struct _index_kobject {
 };
 
 /* pointer to array of kobjects for cpuX/cache/indexY */
-static struct _index_kobject *index_kobject[NR_CPUS];
-#define INDEX_KOBJECT_PTR(x,y)    (&((index_kobject[x])[y]))
+static DEFINE_PER_CPU(struct _index_kobject *, index_kobject);
+#define INDEX_KOBJECT_PTR(x, y)    (&((per_cpu(index_kobject, x))[y]))
 
 #define show_one_plus(file_name, object, val)				\
 static ssize_t show_##file_name						\
@@ -593,9 +593,16 @@ static ssize_t show_size(struct _cpuid4_
 
 static ssize_t show_shared_cpu_map(struct _cpuid4_info *this_leaf, char *buf)
 {
-	char mask_str[NR_CPUS];
-	cpumask_scnprintf(mask_str, NR_CPUS, this_leaf->shared_cpu_map);
-	return sprintf(buf, "%s\n", mask_str);
+	int n = 0;
+	int len = cpumask_scnprintf_len(nr_cpu_ids);
+	char *mask_str = kmalloc(len, GFP_KERNEL);
+
+	if (mask_str) {
+		cpumask_scnprintf(mask_str, len, this_leaf->shared_cpu_map);
+		n = sprintf(buf, "%s\n", mask_str);
+		kfree(mask_str);
+	}
+	return n;
 }
 
 static ssize_t show_type(struct _cpuid4_info *this_leaf, char *buf) {
@@ -684,10 +691,10 @@ static struct kobj_type ktype_percpu_ent
 
 static void __cpuinit cpuid4_cache_sysfs_exit(unsigned int cpu)
 {
-	kfree(cache_kobject[cpu]);
-	kfree(index_kobject[cpu]);
-	cache_kobject[cpu] = NULL;
-	index_kobject[cpu] = NULL;
+	kfree(per_cpu(cache_kobject, cpu));
+	kfree(per_cpu(index_kobject, cpu));
+	per_cpu(cache_kobject, cpu) = NULL;
+	per_cpu(index_kobject, cpu) = NULL;
 	free_cache_attributes(cpu);
 }
 
@@ -703,13 +710,14 @@ static int __cpuinit cpuid4_cache_sysfs_
 		return err;
 
 	/* Allocate all required memory */
-	cache_kobject[cpu] = kzalloc(sizeof(struct kobject), GFP_KERNEL);
-	if (unlikely(cache_kobject[cpu] == NULL))
+	per_cpu(cache_kobject, cpu) =
+		kzalloc(sizeof(struct kobject), GFP_KERNEL);
+	if (unlikely(per_cpu(cache_kobject, cpu) == NULL))
 		goto err_out;
 
-	index_kobject[cpu] = kzalloc(
+	per_cpu(index_kobject, cpu) = kzalloc(
 	    sizeof(struct _index_kobject ) * num_cache_leaves, GFP_KERNEL);
-	if (unlikely(index_kobject[cpu] == NULL))
+	if (unlikely(per_cpu(index_kobject, cpu) == NULL))
 		goto err_out;
 
 	return 0;
@@ -733,7 +741,8 @@ static int __cpuinit cache_add_dev(struc
 	if (unlikely(retval < 0))
 		return retval;
 
-	retval = kobject_init_and_add(cache_kobject[cpu], &ktype_percpu_entry,
+	retval = kobject_init_and_add(per_cpu(cache_kobject, cpu),
+				      &ktype_percpu_entry,
 				      &sys_dev->kobj, "%s", "cache");
 	if (retval < 0) {
 		cpuid4_cache_sysfs_exit(cpu);
@@ -745,13 +754,14 @@ static int __cpuinit cache_add_dev(struc
 		this_object->cpu = cpu;
 		this_object->index = i;
 		retval = kobject_init_and_add(&(this_object->kobj),
-					      &ktype_cache, cache_kobject[cpu],
+					      &ktype_cache,
+					      per_cpu(cache_kobject, cpu),
 					      "index%1lu", i);
 		if (unlikely(retval)) {
 			for (j = 0; j < i; j++) {
 				kobject_put(&(INDEX_KOBJECT_PTR(cpu,j)->kobj));
 			}
-			kobject_put(cache_kobject[cpu]);
+			kobject_put(per_cpu(cache_kobject, cpu));
 			cpuid4_cache_sysfs_exit(cpu);
 			break;
 		}
@@ -760,7 +770,7 @@ static int __cpuinit cache_add_dev(struc
 	if (!retval)
 		cpu_set(cpu, cache_dev_map);
 
-	kobject_uevent(cache_kobject[cpu], KOBJ_ADD);
+	kobject_uevent(per_cpu(cache_kobject, cpu), KOBJ_ADD);
 	return retval;
 }
 
@@ -769,7 +779,7 @@ static void __cpuinit cache_remove_dev(s
 	unsigned int cpu = sys_dev->id;
 	unsigned long i;
 
-	if (cpuid4_info[cpu] == NULL)
+	if (per_cpu(cpuid4_info, cpu) == NULL)
 		return;
 	if (!cpu_isset(cpu, cache_dev_map))
 		return;
@@ -777,7 +787,7 @@ static void __cpuinit cache_remove_dev(s
 
 	for (i = 0; i < num_cache_leaves; i++)
 		kobject_put(&(INDEX_KOBJECT_PTR(cpu,i)->kobj));
-	kobject_put(cache_kobject[cpu]);
+	kobject_put(per_cpu(cache_kobject, cpu));
 	cpuid4_cache_sysfs_exit(cpu);
 }
 

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Re: [PATCH 06/10] x86: reduce memory and stack usage in intel_cacheinfo

[Ingo Molnar]

* Mike Travis <travis@sgi.com> wrote:

> * Change the following static arrays sized by NR_CPUS to
>   per_cpu data variables:
> 
> 	_cpuid4_info *cpuid4_info[NR_CPUS];
> 	_index_kobject *index_kobject[NR_CPUS];
> 	kobject * cache_kobject[NR_CPUS];
> 
> * Remove the local NR_CPUS array with a kmalloc'd region in
>   show_shared_cpu_map().

thanks Travis, i've applied this to x86.git.

one observation:

>  static ssize_t show_shared_cpu_map(struct _cpuid4_info *this_leaf, char *buf)
>  {
> -	char mask_str[NR_CPUS];
> -	cpumask_scnprintf(mask_str, NR_CPUS, this_leaf->shared_cpu_map);
> -	return sprintf(buf, "%s\n", mask_str);
> +	int n = 0;
> +	int len = cpumask_scnprintf_len(nr_cpu_ids);
> +	char *mask_str = kmalloc(len, GFP_KERNEL);
> +
> +	if (mask_str) {
> +		cpumask_scnprintf(mask_str, len, this_leaf->shared_cpu_map);
> +		n = sprintf(buf, "%s\n", mask_str);
> +		kfree(mask_str);
> +	}
> +	return n;

the other changes look good, but this one looks a bit ugly and complex. 
We basically want to sprintf shared_cpu_map into 'buf', but we do that 
by first allocating a temporary buffer, print a string into it, then 
print that string into another buffer ...

this very much smells like an API bug in cpumask_scnprintf() - why dont 
you create a cpumask_scnprintf_ptr() API that takes a pointer to a 
cpumask? Then this change would become a trivial and much more readable:

 -	char mask_str[NR_CPUS];
 -	cpumask_scnprintf(mask_str, NR_CPUS, this_leaf->shared_cpu_map);
 -	return sprintf(buf, "%s\n", mask_str);
 +	return cpumask_scnprintf_ptr(buf, NR_CPUS, &this_leaf->shared_cpu_map);

	Ingo

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Re: [PATCH 06/10] x86: reduce memory and stack usage in intel_cacheinfo

[Mike Travis]

Ingo Molnar wrote:
> * Mike Travis <travis@sgi.com> wrote:
> 
>> * Change the following static arrays sized by NR_CPUS to
>>   per_cpu data variables:
>>
>> 	_cpuid4_info *cpuid4_info[NR_CPUS];
>> 	_index_kobject *index_kobject[NR_CPUS];
>> 	kobject * cache_kobject[NR_CPUS];
>>
>> * Remove the local NR_CPUS array with a kmalloc'd region in
>>   show_shared_cpu_map().
> 
> thanks Travis, i've applied this to x86.git.
> 
> one observation:
> 
>>  static ssize_t show_shared_cpu_map(struct _cpuid4_info *this_leaf, char *buf)
>>  {
>> -	char mask_str[NR_CPUS];
>> -	cpumask_scnprintf(mask_str, NR_CPUS, this_leaf->shared_cpu_map);
>> -	return sprintf(buf, "%s\n", mask_str);
>> +	int n = 0;
>> +	int len = cpumask_scnprintf_len(nr_cpu_ids);
>> +	char *mask_str = kmalloc(len, GFP_KERNEL);
>> +
>> +	if (mask_str) {
>> +		cpumask_scnprintf(mask_str, len, this_leaf->shared_cpu_map);
>> +		n = sprintf(buf, "%s\n", mask_str);
>> +		kfree(mask_str);
>> +	}
>> +	return n;
> 
> the other changes look good, but this one looks a bit ugly and complex. 
> We basically want to sprintf shared_cpu_map into 'buf', but we do that 
> by first allocating a temporary buffer, print a string into it, then 
> print that string into another buffer ...
> 
> this very much smells like an API bug in cpumask_scnprintf() - why dont 
> you create a cpumask_scnprintf_ptr() API that takes a pointer to a 
> cpumask? Then this change would become a trivial and much more readable:
> 
>  -	char mask_str[NR_CPUS];
>  -	cpumask_scnprintf(mask_str, NR_CPUS, this_leaf->shared_cpu_map);
>  -	return sprintf(buf, "%s\n", mask_str);
>  +	return cpumask_scnprintf_ptr(buf, NR_CPUS, &this_leaf->shared_cpu_map);
> 
> 	Ingo

The main goal was to avoid allocating 4096 bytes when only 32 would do
(characters needed to represent nr_cpu_ids cpus instead of NR_CPUS cpus.)
But I'll look at cleaning it up a bit more.  It wouldn't have to be
a function if CHUNKSZ in cpumask_scnprintf() were visible (or a non-changeable
constant.)

Thanks,
Mike

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Re: [PATCH 06/10] x86: reduce memory and stack usage in intel_cacheinfo

[Jeremy Fitzhardinge]

Mike Travis wrote:
> Ingo Molnar wrote:
>   
>> * Mike Travis <travis@sgi.com> wrote:
>>
>>     
>>> * Change the following static arrays sized by NR_CPUS to
>>>   per_cpu data variables:
>>>
>>> 	_cpuid4_info *cpuid4_info[NR_CPUS];
>>> 	_index_kobject *index_kobject[NR_CPUS];
>>> 	kobject * cache_kobject[NR_CPUS];
>>>
>>> * Remove the local NR_CPUS array with a kmalloc'd region in
>>>   show_shared_cpu_map().
>>>       
>> thanks Travis, i've applied this to x86.git.
>>
>> one observation:
>>
>>     
>>>  static ssize_t show_shared_cpu_map(struct _cpuid4_info *this_leaf, char *buf)
>>>  {
>>> -	char mask_str[NR_CPUS];
>>> -	cpumask_scnprintf(mask_str, NR_CPUS, this_leaf->shared_cpu_map);
>>> -	return sprintf(buf, "%s\n", mask_str);
>>> +	int n = 0;
>>> +	int len = cpumask_scnprintf_len(nr_cpu_ids);
>>> +	char *mask_str = kmalloc(len, GFP_KERNEL);
>>> +
>>> +	if (mask_str) {
>>> +		cpumask_scnprintf(mask_str, len, this_leaf->shared_cpu_map);
>>> +		n = sprintf(buf, "%s\n", mask_str);
>>> +		kfree(mask_str);
>>> +	}
>>> +	return n;
>>>       
>> the other changes look good, but this one looks a bit ugly and complex. 
>> We basically want to sprintf shared_cpu_map into 'buf', but we do that 
>> by first allocating a temporary buffer, print a string into it, then 
>> print that string into another buffer ...
>>
>> this very much smells like an API bug in cpumask_scnprintf() - why dont 
>> you create a cpumask_scnprintf_ptr() API that takes a pointer to a 
>> cpumask? Then this change would become a trivial and much more readable:
>>
>>  -	char mask_str[NR_CPUS];
>>  -	cpumask_scnprintf(mask_str, NR_CPUS, this_leaf->shared_cpu_map);
>>  -	return sprintf(buf, "%s\n", mask_str);
>>  +	return cpumask_scnprintf_ptr(buf, NR_CPUS, &this_leaf->shared_cpu_map);
>>
>> 	Ingo
>>     
>
> The main goal was to avoid allocating 4096 bytes when only 32 would do
> (characters needed to represent nr_cpu_ids cpus instead of NR_CPUS cpus.)
> But I'll look at cleaning it up a bit more.  It wouldn't have to be
> a function if CHUNKSZ in cpumask_scnprintf() were visible (or a non-changeable
> constant.)
>   

It's a pity you can't take advantage of kasprintf to handle all this.

Hm, I would say that bitmap_scnprintf is a candidate for implementation 
as a printk format specifier so you could get away from needing a 
special function to print bitmaps...

Eh?  What's the difference between snprintf and scnprintf?

    J

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Re: [PATCH 06/10] x86: reduce memory and stack usage in intel_cacheinfo

[Mike Travis]

Jeremy Fitzhardinge wrote:
> Mike Travis wrote:
>> Ingo Molnar wrote:
>>  
>>> * Mike Travis <travis@sgi.com> wrote:
>>>
>>>    
>>>> * Change the following static arrays sized by NR_CPUS to
>>>>   per_cpu data variables:
>>>>
>>>>     _cpuid4_info *cpuid4_info[NR_CPUS];
>>>>     _index_kobject *index_kobject[NR_CPUS];
>>>>     kobject * cache_kobject[NR_CPUS];
>>>>
>>>> * Remove the local NR_CPUS array with a kmalloc'd region in
>>>>   show_shared_cpu_map().
>>>>       
>>> thanks Travis, i've applied this to x86.git.
>>>
>>> one observation:
>>>
>>>    
>>>>  static ssize_t show_shared_cpu_map(struct _cpuid4_info *this_leaf,
>>>> char *buf)
>>>>  {
>>>> -    char mask_str[NR_CPUS];
>>>> -    cpumask_scnprintf(mask_str, NR_CPUS, this_leaf->shared_cpu_map);
>>>> -    return sprintf(buf, "%s\n", mask_str);
>>>> +    int n = 0;
>>>> +    int len = cpumask_scnprintf_len(nr_cpu_ids);
>>>> +    char *mask_str = kmalloc(len, GFP_KERNEL);
>>>> +
>>>> +    if (mask_str) {
>>>> +        cpumask_scnprintf(mask_str, len, this_leaf->shared_cpu_map);
>>>> +        n = sprintf(buf, "%s\n", mask_str);
>>>> +        kfree(mask_str);
>>>> +    }
>>>> +    return n;
>>>>       
>>> the other changes look good, but this one looks a bit ugly and
>>> complex. We basically want to sprintf shared_cpu_map into 'buf', but
>>> we do that by first allocating a temporary buffer, print a string
>>> into it, then print that string into another buffer ...
>>>
>>> this very much smells like an API bug in cpumask_scnprintf() - why
>>> dont you create a cpumask_scnprintf_ptr() API that takes a pointer to
>>> a cpumask? Then this change would become a trivial and much more
>>> readable:
>>>
>>>  -    char mask_str[NR_CPUS];
>>>  -    cpumask_scnprintf(mask_str, NR_CPUS, this_leaf->shared_cpu_map);
>>>  -    return sprintf(buf, "%s\n", mask_str);
>>>  +    return cpumask_scnprintf_ptr(buf, NR_CPUS,
>>> &this_leaf->shared_cpu_map);
>>>
>>>     Ingo
>>>     
>>
>> The main goal was to avoid allocating 4096 bytes when only 32 would do
>> (characters needed to represent nr_cpu_ids cpus instead of NR_CPUS cpus.)
>> But I'll look at cleaning it up a bit more.  It wouldn't have to be
>> a function if CHUNKSZ in cpumask_scnprintf() were visible (or a
>> non-changeable
>> constant.)
>>   
> 
> It's a pity you can't take advantage of kasprintf to handle all this.
> 
> Hm, I would say that bitmap_scnprintf is a candidate for implementation
> as a printk format specifier so you could get away from needing a
> special function to print bitmaps...

Hmm, I hadn't thought of that.  There is commonly a format spec called
%b for diags, etc. to print bit strings.  Maybe something like:

	"... %*b ...", nr_cpu_ids, ptr_to_bitmap

where the length arg is rounded up to 32 or 64 bits...? 

> 
> Eh?  What's the difference between snprintf and scnprintf?

Good question... I'll have to ask the cpumask person. ;-)
> 
>    J

Thanks!
Mike

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Re: [PATCH 06/10] x86: reduce memory and stack usage in intel_cacheinfo

[Jeremy Fitzhardinge]

Mike Travis wrote:
> Hmm, I hadn't thought of that.  There is commonly a format spec called
> %b for diags, etc. to print bit strings.  Maybe something like:
>
> 	"... %*b ...", nr_cpu_ids, ptr_to_bitmap
>
> where the length arg is rounded up to 32 or 64 bits...? 
>   

I think that would need to be %.*b, but I always need to try it both 
ways anyway...

But yes, that seems like the right way to go.

>> Eh?  What's the difference between snprintf and scnprintf?
>>     
>
> Good question... I'll have to ask the cpumask person. ;-)
>   

It's in generic lib/vsprintf.c.  The two functions are pretty much 
identical...  Oh, I see; snprintf returns the total output size, 
regardless of whether it fits into the provided buffer, but scnprintf 
returns the actual output size, clipped by the buffer length.

    J

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Re: [PATCH 06/10] x86: reduce memory and stack usage in intel_cacheinfo

[Mike Travis]

Jeremy Fitzhardinge wrote:
> Mike Travis wrote:
>> Hmm, I hadn't thought of that.  There is commonly a format spec called
>> %b for diags, etc. to print bit strings.  Maybe something like:
>>
>>     "... %*b ...", nr_cpu_ids, ptr_to_bitmap
>>
>> where the length arg is rounded up to 32 or 64 bits...?   
> 
> I think that would need to be %.*b, but I always need to try it both
> ways anyway...
> 
> But yes, that seems like the right way to go.

I had the same thought after hitting return.

But for this case, I was over thinking the problem.  Turns out that the
number of cpus in a leaf will be fairly small, even with new cpus around
the corner (maybe 64 or 128 cpu threads per leaf?)

So I dropped the cpumask_scnprintf_len() patch and have a new intel_cacheinfo
patch which I'll send in a separate message.

Thanks,
Mike

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Re: [PATCH 06/10] x86: reduce memory and stack usage in intel_cacheinfo

[Ingo Molnar]

* Mike Travis <travis@sgi.com> wrote:

> >> +	int n = 0;
> >> +	int len = cpumask_scnprintf_len(nr_cpu_ids);
> >> +	char *mask_str = kmalloc(len, GFP_KERNEL);
> >> +
> >> +	if (mask_str) {
> >> +		cpumask_scnprintf(mask_str, len, this_leaf->shared_cpu_map);
> >> +		n = sprintf(buf, "%s\n", mask_str);
> >> +		kfree(mask_str);
> >> +	}
> >> +	return n;
> > 
> > the other changes look good, but this one looks a bit ugly and complex. 
> > We basically want to sprintf shared_cpu_map into 'buf', but we do that 
> > by first allocating a temporary buffer, print a string into it, then 
> > print that string into another buffer ...
> > 
> > this very much smells like an API bug in cpumask_scnprintf() - why dont 
> > you create a cpumask_scnprintf_ptr() API that takes a pointer to a 
> > cpumask? Then this change would become a trivial and much more readable:
> > 
> >  -	char mask_str[NR_CPUS];
> >  -	cpumask_scnprintf(mask_str, NR_CPUS, this_leaf->shared_cpu_map);
> >  -	return sprintf(buf, "%s\n", mask_str);
> >  +	return cpumask_scnprintf_ptr(buf, NR_CPUS, &this_leaf->shared_cpu_map);
> > 
> > 	Ingo
> 
> The main goal was to avoid allocating 4096 bytes when only 32 would do 
> (characters needed to represent nr_cpu_ids cpus instead of NR_CPUS 
> cpus.) But I'll look at cleaning it up a bit more.  It wouldn't have 
> to be a function if CHUNKSZ in cpumask_scnprintf() were visible (or a 
> non-changeable constant.)

well, do we care about allocating 4096 bytes, as long as we also free 
it? It's not like we need to clear all the bytes or something. Am i 
missing something here?

	Ingo

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Re: [PATCH 06/10] x86: reduce memory and stack usage in intel_cacheinfo

[H. Peter Anvin]

Ingo Molnar wrote:
>> The main goal was to avoid allocating 4096 bytes when only 32 would do 
>> (characters needed to represent nr_cpu_ids cpus instead of NR_CPUS 
>> cpus.) But I'll look at cleaning it up a bit more.  It wouldn't have 
>> to be a function if CHUNKSZ in cpumask_scnprintf() were visible (or a 
>> non-changeable constant.)
> 
> well, do we care about allocating 4096 bytes, as long as we also free 
> it? It's not like we need to clear all the bytes or something. Am i 
> missing something here?

Well, 32 bytes fits on the stack, whereas 4096 bytes requires allocating 
a page -- which means either taking the risk of failing or blocking.  Of 
course, we're doing this for output, which has the same issue.

	-hpa

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Re: [PATCH 06/10] x86: reduce memory and stack usage in intel_cacheinfo

[Ingo Molnar]

* H. Peter Anvin <hpa@zytor.com> wrote:

> Ingo Molnar wrote:
>>> The main goal was to avoid allocating 4096 bytes when only 32 would do 
>>> (characters needed to represent nr_cpu_ids cpus instead of NR_CPUS cpus.) 
>>> But I'll look at cleaning it up a bit more.  It wouldn't have to be a 
>>> function if CHUNKSZ in cpumask_scnprintf() were visible (or a 
>>> non-changeable constant.)
>>
>> well, do we care about allocating 4096 bytes, as long as we also free it? 
>> It's not like we need to clear all the bytes or something. Am i missing 
>> something here?
>
> Well, 32 bytes fits on the stack, whereas 4096 bytes requires 
> allocating a page -- which means either taking the risk of failing or 
> blocking.  Of course, we're doing this for output, which has the same 
> issue.

hm, i thought this was all implemented via dynamic allocation already, 
within the cpumask_scnprintf function. But i see it doesnt do it - i 
guess a new call could be introduced, cpumask_scnprintf_ptr() which 
passes in a cpumask pointer and does dynamic allocation itself?

	Ingo

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Re: [PATCH 06/10] x86: reduce memory and stack usage in intel_cacheinfo

[Mike Travis]

Ingo Molnar wrote:
> * H. Peter Anvin <hpa@zytor.com> wrote:
> 
>> Ingo Molnar wrote:
>>>> The main goal was to avoid allocating 4096 bytes when only 32 would do 
>>>> (characters needed to represent nr_cpu_ids cpus instead of NR_CPUS cpus.) 
>>>> But I'll look at cleaning it up a bit more.  It wouldn't have to be a 
>>>> function if CHUNKSZ in cpumask_scnprintf() were visible (or a 
>>>> non-changeable constant.)
>>> well, do we care about allocating 4096 bytes, as long as we also free it? 
>>> It's not like we need to clear all the bytes or something. Am i missing 
>>> something here?
>> Well, 32 bytes fits on the stack, whereas 4096 bytes requires 
>> allocating a page -- which means either taking the risk of failing or 
>> blocking.  Of course, we're doing this for output, which has the same 
>> issue.
> 
> hm, i thought this was all implemented via dynamic allocation already, 
> within the cpumask_scnprintf function. But i see it doesnt do it - i 
> guess a new call could be introduced, cpumask_scnprintf_ptr() which 
> passes in a cpumask pointer and does dynamic allocation itself?
> 
> 	Ingo

Here's a snippet of the new patch.  This works fine (I think) for
cpus on a leaf.  The sched_debug_one problem should work the same way,
hopefully ;-)

[sorry, cut and pasted so no tabs]

 static ssize_t show_shared_cpu_map(struct _cpuid4_info *this_leaf, char *buf)
 {
-       char mask_str[NR_CPUS];
-       cpumask_scnprintf(mask_str, NR_CPUS, this_leaf->shared_cpu_map);
-       return sprintf(buf, "%s\n", mask_str);
+       /*
+        * cpulist_scnprintf() has the advantage of compressing
+        * consecutive cpu numbers into a single range which seems
+        * appropriate for cpus on a leaf.  This will change what is
+        * output so scripts that process the output will have to change.
+        * The good news is that the output format is compatible
+        * with cpulist_parse() [bitmap_parselist()].
+        *
+        * Have to guess at output buffer size... 128 seems reasonable
+        * to represent all cpus on a leaf in the worst case, like
+        * if all cpus are non-consecutive and large numbers.
+        */
+       return cpulist_scnprintf(buf, 128, this_leaf->shared_cpu_map);
 }

Thanks,
Mike

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[PATCH 07/10] cpu: change cpu_sys_devices from array to per_cpu variable

[Mike Travis]

[-- Attachment #1: nr_cpus-in-cpu_c --]
[-- Type: text/plain, Size: 1860 bytes --]

Change cpu_sys_devices from array to per_cpu variable in
drivers/base/cpu.c.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
	git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git

(MAINTAINER unknown)
Signed-off-by: Mike Travis <travis@sgi.com>
---
 drivers/base/cpu.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

--- linux.trees.git.orig/drivers/base/cpu.c
+++ linux.trees.git/drivers/base/cpu.c
@@ -18,7 +18,7 @@ struct sysdev_class cpu_sysdev_class = {
 };
 EXPORT_SYMBOL(cpu_sysdev_class);
 
-static struct sys_device *cpu_sys_devices[NR_CPUS];
+static DEFINE_PER_CPU(struct sys_device *, cpu_sys_devices);
 
 #ifdef CONFIG_HOTPLUG_CPU
 static ssize_t show_online(struct sys_device *dev, char *buf)
@@ -68,7 +68,7 @@ void unregister_cpu(struct cpu *cpu)
 	sysdev_remove_file(&cpu->sysdev, &attr_online);
 
 	sysdev_unregister(&cpu->sysdev);
-	cpu_sys_devices[logical_cpu] = NULL;
+	per_cpu(cpu_sys_devices, logical_cpu) = NULL;
 	return;
 }
 #else /* ... !CONFIG_HOTPLUG_CPU */
@@ -122,7 +122,7 @@ int __cpuinit register_cpu(struct cpu *c
 	if (!error && cpu->hotpluggable)
 		register_cpu_control(cpu);
 	if (!error)
-		cpu_sys_devices[num] = &cpu->sysdev;
+		per_cpu(cpu_sys_devices, num) = &cpu->sysdev;
 	if (!error)
 		register_cpu_under_node(num, cpu_to_node(num));
 
@@ -135,8 +135,8 @@ int __cpuinit register_cpu(struct cpu *c
 
 struct sys_device *get_cpu_sysdev(unsigned cpu)
 {
-	if (cpu < NR_CPUS)
-		return cpu_sys_devices[cpu];
+	if (cpu < nr_cpu_ids && cpu_possible(cpu))
+		return per_cpu(cpu_sys_devices, cpu);
 	else
 		return NULL;
 }

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[PATCH 08/10] net: remove NR_CPUS arrays in net/core/dev.c v2

[Mike Travis]

[-- Attachment #1: nr_cpus-in-net_core_dev --]
[-- Type: text/plain, Size: 2371 bytes --]

Remove the fixed size channels[NR_CPUS] array in
net/core/dev.c and dynamically allocate array based on
nr_cpu_ids.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
	git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git

Cc: David S. Miller <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Mike Travis <travis@sgi.com>
---
v2: fixed logic error in netdev_dma_register().
---
 net/core/dev.c |   15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

--- linux.trees.git.orig/net/core/dev.c
+++ linux.trees.git/net/core/dev.c
@@ -162,7 +162,7 @@ struct net_dma {
 	struct dma_client client;
 	spinlock_t lock;
 	cpumask_t channel_mask;
-	struct dma_chan *channels[NR_CPUS];
+	struct dma_chan **channels;
 };
 
 static enum dma_state_client
@@ -2444,7 +2444,7 @@ static struct netif_rx_stats *softnet_ge
 {
 	struct netif_rx_stats *rc = NULL;
 
-	while (*pos < NR_CPUS)
+	while (*pos < nr_cpu_ids)
 		if (cpu_online(*pos)) {
 			rc = &per_cpu(netdev_rx_stat, *pos);
 			break;
@@ -4316,7 +4316,7 @@ netdev_dma_event(struct dma_client *clie
 	spin_lock(&net_dma->lock);
 	switch (state) {
 	case DMA_RESOURCE_AVAILABLE:
-		for (i = 0; i < NR_CPUS; i++)
+		for (i = 0; i < nr_cpu_ids; i++)
 			if (net_dma->channels[i] == chan) {
 				found = 1;
 				break;
@@ -4331,7 +4331,7 @@ netdev_dma_event(struct dma_client *clie
 		}
 		break;
 	case DMA_RESOURCE_REMOVED:
-		for (i = 0; i < NR_CPUS; i++)
+		for (i = 0; i < nr_cpu_ids; i++)
 			if (net_dma->channels[i] == chan) {
 				found = 1;
 				pos = i;
@@ -4358,6 +4358,13 @@ netdev_dma_event(struct dma_client *clie
  */
 static int __init netdev_dma_register(void)
 {
+	net_dma.channels = kzalloc(nr_cpu_ids * sizeof(struct net_dma),
+								GFP_KERNEL);
+	if (unlikely(!net_dma.channels)) {
+		printk(KERN_NOTICE
+				"netdev_dma: no memory for net_dma.channels\n");
+		return -ENOMEM;
+	}
 	spin_lock_init(&net_dma.lock);
 	dma_cap_set(DMA_MEMCPY, net_dma.client.cap_mask);
 	dma_async_client_register(&net_dma.client);

-- 

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[PATCH 09/10] x86: oprofile: remove NR_CPUS arrays in arch/x86/oprofile/nmi_int.c

[Mike Travis]

[-- Attachment #1: nr_cpus-in-nmi_int_c --]
[-- Type: text/plain, Size: 5867 bytes --]

Change the following arrays sized by NR_CPUS to be PERCPU variables:

	static struct op_msrs cpu_msrs[NR_CPUS];
	static unsigned long saved_lvtpc[NR_CPUS];

Also some minor complaints from checkpatch.pl fixed.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
	git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git

Cc: Philippe Elie <phil.el@wanadoo.fr>

Signed-off-by: Mike Travis <travis@sgi.com>
---

All changes were transparent except for:

 static void nmi_shutdown(void)
 {
+	struct op_msrs *msrs = &__get_cpu_var(cpu_msrs);
 	nmi_enabled = 0;
 	on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1);
 	unregister_die_notifier(&profile_exceptions_nb);
-	model->shutdown(cpu_msrs);
+	model->shutdown(msrs);
 	free_msrs();
 }

The existing code passed a reference to cpu 0's instance of struct op_msrs
to model->shutdown, whilst the other functions are passed a reference to
<this cpu's> instance of a struct op_msrs.  This seemed to be a bug to me
even though as long as cpu 0 and <this cpu> are of the same type it would
have the same effect...?
---
 arch/x86/oprofile/nmi_int.c |   49 ++++++++++++++++++++++++--------------------
 1 file changed, 27 insertions(+), 22 deletions(-)

--- linux.trees.git.orig/arch/x86/oprofile/nmi_int.c
+++ linux.trees.git/arch/x86/oprofile/nmi_int.c
@@ -23,8 +23,8 @@
 #include "op_x86_model.h"
 
 static struct op_x86_model_spec const *model;
-static struct op_msrs cpu_msrs[NR_CPUS];
-static unsigned long saved_lvtpc[NR_CPUS];
+static DEFINE_PER_CPU(struct op_msrs, cpu_msrs);
+static DEFINE_PER_CPU(unsigned long, saved_lvtpc);
 
 static int nmi_start(void);
 static void nmi_stop(void);
@@ -89,7 +89,7 @@ static int profile_exceptions_notify(str
 
 	switch (val) {
 	case DIE_NMI:
-		if (model->check_ctrs(args->regs, &cpu_msrs[cpu]))
+		if (model->check_ctrs(args->regs, &per_cpu(cpu_msrs, cpu)))
 			ret = NOTIFY_STOP;
 		break;
 	default:
@@ -126,7 +126,7 @@ static void nmi_cpu_save_registers(struc
 static void nmi_save_registers(void *dummy)
 {
 	int cpu = smp_processor_id();
-	struct op_msrs *msrs = &cpu_msrs[cpu];
+	struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
 	nmi_cpu_save_registers(msrs);
 }
 
@@ -134,10 +134,10 @@ static void free_msrs(void)
 {
 	int i;
 	for_each_possible_cpu(i) {
-		kfree(cpu_msrs[i].counters);
-		cpu_msrs[i].counters = NULL;
-		kfree(cpu_msrs[i].controls);
-		cpu_msrs[i].controls = NULL;
+		kfree(per_cpu(cpu_msrs, i).counters);
+		per_cpu(cpu_msrs, i).counters = NULL;
+		kfree(per_cpu(cpu_msrs, i).controls);
+		per_cpu(cpu_msrs, i).controls = NULL;
 	}
 }
 
@@ -149,13 +149,15 @@ static int allocate_msrs(void)
 
 	int i;
 	for_each_possible_cpu(i) {
-		cpu_msrs[i].counters = kmalloc(counters_size, GFP_KERNEL);
-		if (!cpu_msrs[i].counters) {
+		per_cpu(cpu_msrs, i).counters = kmalloc(counters_size,
+								GFP_KERNEL);
+		if (!per_cpu(cpu_msrs, i).counters) {
 			success = 0;
 			break;
 		}
-		cpu_msrs[i].controls = kmalloc(controls_size, GFP_KERNEL);
-		if (!cpu_msrs[i].controls) {
+		per_cpu(cpu_msrs, i).controls = kmalloc(controls_size,
+								GFP_KERNEL);
+		if (!per_cpu(cpu_msrs, i).controls) {
 			success = 0;
 			break;
 		}
@@ -170,11 +172,11 @@ static int allocate_msrs(void)
 static void nmi_cpu_setup(void *dummy)
 {
 	int cpu = smp_processor_id();
-	struct op_msrs *msrs = &cpu_msrs[cpu];
+	struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
 	spin_lock(&oprofilefs_lock);
 	model->setup_ctrs(msrs);
 	spin_unlock(&oprofilefs_lock);
-	saved_lvtpc[cpu] = apic_read(APIC_LVTPC);
+	per_cpu(saved_lvtpc, cpu) = apic_read(APIC_LVTPC);
 	apic_write(APIC_LVTPC, APIC_DM_NMI);
 }
 
@@ -203,13 +205,15 @@ static int nmi_setup(void)
 	 */
 
 	/* Assume saved/restored counters are the same on all CPUs */
-	model->fill_in_addresses(&cpu_msrs[0]);
+	model->fill_in_addresses(&per_cpu(cpu_msrs, 0));
 	for_each_possible_cpu(cpu) {
 		if (cpu != 0) {
-			memcpy(cpu_msrs[cpu].counters, cpu_msrs[0].counters,
+			memcpy(per_cpu(cpu_msrs, cpu).counters,
+				per_cpu(cpu_msrs, 0).counters,
 				sizeof(struct op_msr) * model->num_counters);
 
-			memcpy(cpu_msrs[cpu].controls, cpu_msrs[0].controls,
+			memcpy(per_cpu(cpu_msrs, cpu).controls,
+				per_cpu(cpu_msrs, 0).controls,
 				sizeof(struct op_msr) * model->num_controls);
 		}
 
@@ -249,7 +253,7 @@ static void nmi_cpu_shutdown(void *dummy
 {
 	unsigned int v;
 	int cpu = smp_processor_id();
-	struct op_msrs *msrs = &cpu_msrs[cpu];
+	struct op_msrs *msrs = &__get_cpu_var(cpu_msrs);
 
 	/* restoring APIC_LVTPC can trigger an apic error because the delivery
 	 * mode and vector nr combination can be illegal. That's by design: on
@@ -258,23 +262,24 @@ static void nmi_cpu_shutdown(void *dummy
 	 */
 	v = apic_read(APIC_LVTERR);
 	apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
-	apic_write(APIC_LVTPC, saved_lvtpc[cpu]);
+	apic_write(APIC_LVTPC, per_cpu(saved_lvtpc, cpu));
 	apic_write(APIC_LVTERR, v);
 	nmi_restore_registers(msrs);
 }
 
 static void nmi_shutdown(void)
 {
+	struct op_msrs *msrs = &__get_cpu_var(cpu_msrs);
 	nmi_enabled = 0;
 	on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1);
 	unregister_die_notifier(&profile_exceptions_nb);
-	model->shutdown(cpu_msrs);
+	model->shutdown(msrs);
 	free_msrs();
 }
 
 static void nmi_cpu_start(void *dummy)
 {
-	struct op_msrs const *msrs = &cpu_msrs[smp_processor_id()];
+	struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
 	model->start(msrs);
 }
 
@@ -286,7 +291,7 @@ static int nmi_start(void)
 
 static void nmi_cpu_stop(void *dummy)
 {
-	struct op_msrs const *msrs = &cpu_msrs[smp_processor_id()];
+	struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
 	model->stop(msrs);
 }
 

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Re: [PATCH 09/10] x86: oprofile: remove NR_CPUS arrays in arch/x86/oprofile/nmi_int.c

[Ingo Molnar]

* Mike Travis <travis@sgi.com> wrote:

> Change the following arrays sized by NR_CPUS to be PERCPU variables:
> 
> 	static struct op_msrs cpu_msrs[NR_CPUS];
> 	static unsigned long saved_lvtpc[NR_CPUS];
> 
> Also some minor complaints from checkpatch.pl fixed.

thanks, applied.

> All changes were transparent except for:
> 
>  static void nmi_shutdown(void)
>  {
> +	struct op_msrs *msrs = &__get_cpu_var(cpu_msrs);
>  	nmi_enabled = 0;
>  	on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1);
>  	unregister_die_notifier(&profile_exceptions_nb);
> -	model->shutdown(cpu_msrs);
> +	model->shutdown(msrs);
>  	free_msrs();
>  }
> 
> The existing code passed a reference to cpu 0's instance of struct 
> op_msrs to model->shutdown, whilst the other functions are passed a 
> reference to <this cpu's> instance of a struct op_msrs.  This seemed 
> to be a bug to me even though as long as cpu 0 and <this cpu> are of 
> the same type it would have the same effect...?

i dont think this has any real effect in practice (the model pointers 
are not expected to change across cpus on the same system) - but in any 
case i've promoted your observation to the main portion of the changelog 
so that we'll have notice of this.

(someone might want to play with simulating a weaker CPU on a secondary 
core, but we've got tons of other assumptions on CPU type symmetry.)

	Ingo

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[PATCH 10/10] sched: Remove fixed NR_CPUS sized arrays in kernel_sched.c

[Mike Travis]

[-- Attachment #1: nr_cpus-in-kernel_sched --]
[-- Type: text/plain, Size: 7993 bytes --]

Change fixed size arrays to per_cpu variables or dynamically allocated
arrays in sched_init() and sched_init_smp().

 (1)	static struct sched_entity *init_sched_entity_p[NR_CPUS];
 (1)	static struct cfs_rq *init_cfs_rq_p[NR_CPUS];
 (1)	static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS];
 (1)	static struct rt_rq *init_rt_rq_p[NR_CPUS];
	static struct sched_group **sched_group_nodes_bycpu[NR_CPUS];
	char str[NR_CPUS];
	int ints[NR_CPUS], i;

(1 - these arrays are allocated via alloc_bootmem_low())

Also in sched_create_group() we allocate new arrays based on nr_cpu_ids.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
	git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git

Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Travis <travis@sgi.com>
---
 kernel/sched.c |   92 +++++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 63 insertions(+), 29 deletions(-)

--- linux.trees.git.orig/kernel/sched.c
+++ linux.trees.git/kernel/sched.c
@@ -66,6 +66,7 @@
 #include <linux/unistd.h>
 #include <linux/pagemap.h>
 #include <linux/hrtimer.h>
+#include <linux/bootmem.h>
 
 #include <asm/tlb.h>
 #include <asm/irq_regs.h>
@@ -193,17 +194,11 @@ struct task_group {
 static DEFINE_PER_CPU(struct sched_entity, init_sched_entity);
 /* Default task group's cfs_rq on each cpu */
 static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp;
-
-static struct sched_entity *init_sched_entity_p[NR_CPUS];
-static struct cfs_rq *init_cfs_rq_p[NR_CPUS];
 #endif
 
 #ifdef CONFIG_RT_GROUP_SCHED
 static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity);
 static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp;
-
-static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS];
-static struct rt_rq *init_rt_rq_p[NR_CPUS];
 #endif
 
 /* task_group_lock serializes add/remove of task groups and also changes to
@@ -227,17 +222,7 @@ static int init_task_group_load = INIT_T
 /* Default task group.
  *	Every task in system belong to this group at bootup.
  */
-struct task_group init_task_group = {
-#ifdef CONFIG_FAIR_GROUP_SCHED
-	.se	= init_sched_entity_p,
-	.cfs_rq = init_cfs_rq_p,
-#endif
-
-#ifdef CONFIG_RT_GROUP_SCHED
-	.rt_se	= init_sched_rt_entity_p,
-	.rt_rq	= init_rt_rq_p,
-#endif
-};
+struct task_group init_task_group;
 
 /* return group to which a task belongs */
 static inline struct task_group *task_group(struct task_struct *p)
@@ -3518,7 +3503,7 @@ static inline void trigger_load_balance(
 			 */
 			int ilb = first_cpu(nohz.cpu_mask);
 
-			if (ilb != NR_CPUS)
+			if (ilb < nr_cpu_ids)
 				resched_cpu(ilb);
 		}
 	}
@@ -5470,11 +5455,11 @@ static void move_task_off_dead_cpu(int d
 		dest_cpu = any_online_cpu(mask);
 
 		/* On any allowed CPU? */
-		if (dest_cpu == NR_CPUS)
+		if (dest_cpu >= nr_cpu_ids)
 			dest_cpu = any_online_cpu(p->cpus_allowed);
 
 		/* No more Mr. Nice Guy. */
-		if (dest_cpu == NR_CPUS) {
+		if (dest_cpu >= nr_cpu_ids) {
 			cpumask_t cpus_allowed = cpuset_cpus_allowed_locked(p);
 			/*
 			 * Try to stay on the same cpuset, where the
@@ -5929,9 +5914,16 @@ static int sched_domain_debug_one(struct
 {
 	struct sched_group *group = sd->groups;
 	cpumask_t groupmask;
-	char str[NR_CPUS];
+	int len = cpumask_scnprintf_len(nr_cpu_ids);
+	char *str = kmalloc(len, GFP_KERNEL);
+	int ret = 0;
+
+	if (!str) {
+		printk(KERN_DEBUG "Cannot load-balance (no memory)\n");
+		return -1;
+	}
 
-	cpumask_scnprintf(str, NR_CPUS, sd->span);
+	cpumask_scnprintf(str, len, sd->span);
 	cpus_clear(groupmask);
 
 	printk(KERN_DEBUG "%*s domain %d: ", level, "", level);
@@ -5941,6 +5933,7 @@ static int sched_domain_debug_one(struct
 		if (sd->parent)
 			printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain"
 					" has parent");
+		kfree(str);
 		return -1;
 	}
 
@@ -5984,7 +5977,7 @@ static int sched_domain_debug_one(struct
 
 		cpus_or(groupmask, groupmask, group->cpumask);
 
-		cpumask_scnprintf(str, NR_CPUS, group->cpumask);
+		cpumask_scnprintf(str, len, group->cpumask);
 		printk(KERN_CONT " %s", str);
 
 		group = group->next;
@@ -5997,6 +5990,8 @@ static int sched_domain_debug_one(struct
 	if (sd->parent && !cpus_subset(groupmask, sd->parent->span))
 		printk(KERN_ERR "ERROR: parent span is not a superset "
 			"of domain->span\n");
+
+	kfree(str);
 	return 0;
 }
 
@@ -6198,7 +6193,7 @@ __setup("isolcpus=", isolated_cpu_setup)
 /*
  * init_sched_build_groups takes the cpumask we wish to span, and a pointer
  * to a function which identifies what group(along with sched group) a CPU
- * belongs to. The return value of group_fn must be a >= 0 and < NR_CPUS
+ * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids
  * (due to the fact that we keep track of groups covered with a cpumask_t).
  *
  * init_sched_build_groups will build a circular linked list of the groups
@@ -6396,7 +6391,7 @@ cpu_to_phys_group(int cpu, const cpumask
  * gets dynamically allocated.
  */
 static DEFINE_PER_CPU(struct sched_domain, node_domains);
-static struct sched_group **sched_group_nodes_bycpu[NR_CPUS];
+static struct sched_group ***sched_group_nodes_bycpu;
 
 static DEFINE_PER_CPU(struct sched_domain, allnodes_domains);
 static DEFINE_PER_CPU(struct sched_group, sched_group_allnodes);
@@ -7039,6 +7034,11 @@ void __init sched_init_smp(void)
 {
 	cpumask_t non_isolated_cpus;
 
+#if defined(CONFIG_NUMA)
+	sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **),
+								GFP_KERNEL);
+	BUG_ON(sched_group_nodes_bycpu == NULL);
+#endif
 	get_online_cpus();
 	arch_init_sched_domains(&cpu_online_map);
 	cpus_andnot(non_isolated_cpus, cpu_possible_map, cpu_isolated_map);
@@ -7056,6 +7056,11 @@ void __init sched_init_smp(void)
 #else
 void __init sched_init_smp(void)
 {
+#if defined(CONFIG_NUMA)
+	sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **),
+								GFP_KERNEL);
+	BUG_ON(sched_group_nodes_bycpu == NULL);
+#endif
 	sched_init_granularity();
 }
 #endif /* CONFIG_SMP */
@@ -7149,6 +7154,35 @@ static void init_tg_rt_entry(struct rq *
 void __init sched_init(void)
 {
 	int i, j;
+	unsigned long alloc_size = 0, ptr;
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+	alloc_size += 2 * nr_cpu_ids * sizeof(void **);
+#endif
+#ifdef CONFIG_RT_GROUP_SCHED
+	alloc_size += 2 * nr_cpu_ids * sizeof(void **);
+#endif
+	/*
+	 * As sched_init() is called before page_alloc is setup,
+	 * we use alloc_bootmem().
+	 */
+	if (alloc_size) {
+		ptr = (unsigned long)alloc_bootmem_low(alloc_size);
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+		init_task_group.se = (struct sched_entity **)ptr;
+		ptr += nr_cpu_ids * sizeof(void **);
+
+		init_task_group.cfs_rq = (struct cfs_rq **)ptr;
+		ptr += nr_cpu_ids * sizeof(void **);
+#endif
+#ifdef CONFIG_RT_GROUP_SCHED
+		init_task_group.rt_se = (struct sched_rt_entity **)ptr;
+		ptr += nr_cpu_ids * sizeof(void **);
+
+		init_task_group.rt_rq = (struct rt_rq **)ptr;
+#endif
+	}
 
 #ifdef CONFIG_SMP
 	init_defrootdomain();
@@ -7394,10 +7428,10 @@ static int alloc_fair_sched_group(struct
 	struct rq *rq;
 	int i;
 
-	tg->cfs_rq = kzalloc(sizeof(cfs_rq) * NR_CPUS, GFP_KERNEL);
+	tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL);
 	if (!tg->cfs_rq)
 		goto err;
-	tg->se = kzalloc(sizeof(se) * NR_CPUS, GFP_KERNEL);
+	tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL);
 	if (!tg->se)
 		goto err;
 
@@ -7477,10 +7511,10 @@ static int alloc_rt_sched_group(struct t
 	struct rq *rq;
 	int i;
 
-	tg->rt_rq = kzalloc(sizeof(rt_rq) * NR_CPUS, GFP_KERNEL);
+	tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL);
 	if (!tg->rt_rq)
 		goto err;
-	tg->rt_se = kzalloc(sizeof(rt_se) * NR_CPUS, GFP_KERNEL);
+	tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL);
 	if (!tg->rt_se)
 		goto err;
 

-- 

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Re: [PATCH 00/10] NR_CPUS: third reduction of NR_CPUS memory usage x86-version v2

[Ingo Molnar]

* Mike Travis <travis@sgi.com> wrote:

> Wii, isn't this fun...!  This is a resubmission of yesterday's patches 
> based on the x86.git/latest tree.  Yes, it _is_ a maze of twisty litle 
> passages. ;-)

just to make patch dependencies clear: most of the patches here can be 
applied to their base trees as-is, without depending on any other patch, 
correct?

the only undeclared dependency i found was the cpumask_scnprintf_len() 
patch - please prominently list dependencies in the changelog like this:

 [ this patch depends on "cpumask: Add cpumask_scnprintf_len function" ]

	Ingo

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Re: [PATCH 00/10] NR_CPUS: third reduction of NR_CPUS memory usage x86-version v2

[Mike Travis]

Ingo Molnar wrote:
> * Mike Travis <travis@sgi.com> wrote:
> 
>> Wii, isn't this fun...!  This is a resubmission of yesterday's patches 
>> based on the x86.git/latest tree.  Yes, it _is_ a maze of twisty litle 
>> passages. ;-)
> 
> just to make patch dependencies clear: most of the patches here can be 
> applied to their base trees as-is, without depending on any other patch, 
> correct?
> 
> the only undeclared dependency i found was the cpumask_scnprintf_len() 
> patch - please prominently list dependencies in the changelog like this:
> 
>  [ this patch depends on "cpumask: Add cpumask_scnprintf_len function" ]
> 
> 	Ingo


Ahh, ok.  I was under the assumption that an entire patchset would be
applied en-mass and only divided up by bi-sect debugging...?

The second patchset (cpumask) is highly incremental and I did it like
this to show memory gains (or losses).  I tossed a few patches that
didn't have any overall goodness (and have a few more to help with
the memory footprint or performance in the queue.)

Thanks,
Mike

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[PATCH 00/10] NR_CPUS: third reduction of NR_CPUS memory usage

[Mike Travis]

Here's the third round of removing static allocations of arrays using
NR_CPUS to size the length.  The change is to use PER_CPU variables in
place of the static tables, or allocate the array based on nr_cpu_ids.

In addition, there's a cleanup of x86 non-smp code, the movement of
setting nr_cpu_ids to setup_per_cpu_areas() so it's available as soon
as possible, and a new function cpumask_scnprintf_len() to return the
number of characters needed to display "len" cpumask bits.

Affected files:

	arch/ia64/kernel/acpi.c
	arch/ia64/kernel/setup.c
	arch/powerpc/kernel/setup_64.c
	arch/sparc64/mm/init.c
	arch/x86/kernel/cpu/intel_cacheinfo.c
	arch/x86/kernel/genapic_64.c
	arch/x86/kernel/mpparse_64.c
	arch/x86/kernel/setup64.c
	arch/x86/kernel/smpboot_32.c
	arch/x86/mm/numa_64.c
	arch/x86/oprofile/nmi_int.c
	drivers/acpi/processor_core.c
	drivers/acpi/processor_idle.c
	drivers/acpi/processor_perflib.c
	drivers/acpi/processor_throttling.c
	drivers/base/cpu.c
	drivers/cpufreq/cpufreq.c
	drivers/cpufreq/cpufreq_stats.c
	drivers/cpufreq/freq_table.c
	include/acpi/processor.h
	include/asm-x86/smp_32.h
	include/asm-x86/smp_64.h
	include/asm-x86/topology.h
	include/linux/bitmap.h
	include/linux/cpumask.h
	init/main.c
	kernel/sched.c
	lib/bitmap.c
	net/core/dev.c

Based on linux-2.6.25-rc5-mm1

Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Andi Kleen <ak@suse.de>
Cc: Anton Blanchard <anton@samba.org>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: David S. Miller <davem@davemloft.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Paul Jackson <pj@sgi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Philippe Elie <phil.el@wanadoo.fr>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: William L. Irwin <wli@holomorphy.com>

Signed-off-by: Mike Travis <travis@sgi.com>
---

I moved the x86_64 cleanup and move-set-nr_cpu_ids from the zero-based
percpu variables patchset to this one, as I was encountering a panic
from system_call_after_swapgs() after an unknown device interrupt during
module loading.  That problem will be dealt with in another patch.


Here's the various effects of the patches on memory usages using the
akpm2 config file with NR_CPUS=4096 and MAXNODES=512:

====== Data (-l 500)
    1 - initial
    2 - cleanup
    4 - nr_cpus-in-cpufreq-cpu_alloc
    5 - nr_cpus-in-acpi-driver-cpu_alloc
    7 - nr_cpus-in-intel_cacheinfo
    8 - nr_cpus-in-cpu_c
   11 - nr_cpus-in-kernel_sched

    .1.   .2.     .4.     .5.   .7.     .8.    .11.  
  32768     .  -32768       .     .       .       .   show_table(.bss)
  32768     .       .       .     .       .  -32768   sched_group_nodes_bycpu(.bss)
  32768     .       .  -32768     .       .       .   processors(.bss)
  32768     .       .  -32768     .       .       .   processor_device_array(.bss)
  32768     .       .       .     .       .  -32768   init_sched_entity_p(.bss)
  32768     .       .       .     .       .  -32768   init_cfs_rq_p(.bss)
  32768     .       .       .-32768       .       .   index_kobject(.bss)
  32768     .       .       .-32768       .       .   cpuid4_info(.bss)
  32768     .  -32768       .     .       .       .   cpufreq_cpu_governor(.bss)
  32768     .  -32768       .     .       .       .   cpufreq_cpu_data(.bss)
  32768     .       .       .     .  -32768       .   cpu_sys_devices(.bss)
  32768     .       .       .-32768       .       .   cache_kobject(.bss)

====== Text/Data ()
    1 - initial
    4 - nr_cpus-in-cpufreq-cpu_alloc
    5 - nr_cpus-in-acpi-driver-cpu_alloc
    7 - nr_cpus-in-intel_cacheinfo
    8 - nr_cpus-in-cpu_c
   11 - nr_cpus-in-kernel_sched

       .1.     .4.     .5.     .7.     .8.    .11.    ..final..
   3373056       .   +2048       .       .       . 3375104    <1%  TextSize
   1656832       .   +2048       .       .       . 1658880    <1%  DataSize
   1855488  -98304  -65536  -98304  -32768  -98304 1462272   -21%  BssSize
  10395648       .   +4096       .       .       . 10399744   <1%  OtherSize
  17281024  -98304  -57344  -98304  -32768  -98304 16896000   -2%  Totals

====== Stack (-l 500)
... files 11 vars 928 all 0 lim 500 unch 0

    1 - initial
    7 - nr_cpus-in-intel_cacheinfo
   11 - nr_cpus-in-kernel_sched

   .1.    .7.   .11.    ..final..
  4648      .  -4080  568   -87%  cpu_attach_domain
  4104  -4104      .    .  -100%  show_shared_cpu_map
  8752  -4104  -4080  568   -93%  Totals

-- 

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[PATCH 09/10] x86: oprofile: remove NR_CPUS arrays in arch/x86/oprofile/nmi_int.c

[Mike Travis]

[-- Attachment #1: nr_cpus-in-nmi_int_c --]
[-- Type: text/plain, Size: 5750 bytes --]

Change the following arrays sized by NR_CPUS to be PERCPU variables:

	static struct op_msrs cpu_msrs[NR_CPUS];
	static unsigned long saved_lvtpc[NR_CPUS];

Also some minor complaints from checkpatch.pl fixed.

Based on linux-2.6.25-rc5-mm1

Cc: Philippe Elie <phil.el@wanadoo.fr>

Signed-off-by: Mike Travis <travis@sgi.com>
---

All changes were transparent except for:

 static void nmi_shutdown(void)
 {
+	struct op_msrs *msrs = &__get_cpu_var(cpu_msrs);
 	nmi_enabled = 0;
 	on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1);
 	unregister_die_notifier(&profile_exceptions_nb);
-	model->shutdown(cpu_msrs);
+	model->shutdown(msrs);
 	free_msrs();
 }

The existing code passed a reference to cpu 0's instance of struct op_msrs
to model->shutdown, whilst the other functions are passed a reference to
<this cpu's> instance of a struct op_msrs.  This seemed to be a bug to me
even though as long as cpu 0 and <this cpu> are of the same type it would
have the same effect...?
---
 arch/x86/oprofile/nmi_int.c |   49 ++++++++++++++++++++++++--------------------
 1 file changed, 27 insertions(+), 22 deletions(-)

--- linux-2.6.25-rc5.orig/arch/x86/oprofile/nmi_int.c
+++ linux-2.6.25-rc5/arch/x86/oprofile/nmi_int.c
@@ -23,8 +23,8 @@
 #include "op_x86_model.h"
 
 static struct op_x86_model_spec const *model;
-static struct op_msrs cpu_msrs[NR_CPUS];
-static unsigned long saved_lvtpc[NR_CPUS];
+static DEFINE_PER_CPU(struct op_msrs, cpu_msrs);
+static DEFINE_PER_CPU(unsigned long, saved_lvtpc);
 
 static int nmi_start(void);
 static void nmi_stop(void);
@@ -89,7 +89,7 @@ static int profile_exceptions_notify(str
 
 	switch (val) {
 	case DIE_NMI:
-		if (model->check_ctrs(args->regs, &cpu_msrs[cpu]))
+		if (model->check_ctrs(args->regs, &per_cpu(cpu_msrs, cpu)))
 			ret = NOTIFY_STOP;
 		break;
 	default:
@@ -126,7 +126,7 @@ static void nmi_cpu_save_registers(struc
 static void nmi_save_registers(void *dummy)
 {
 	int cpu = smp_processor_id();
-	struct op_msrs *msrs = &cpu_msrs[cpu];
+	struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
 	nmi_cpu_save_registers(msrs);
 }
 
@@ -134,10 +134,10 @@ static void free_msrs(void)
 {
 	int i;
 	for_each_possible_cpu(i) {
-		kfree(cpu_msrs[i].counters);
-		cpu_msrs[i].counters = NULL;
-		kfree(cpu_msrs[i].controls);
-		cpu_msrs[i].controls = NULL;
+		kfree(per_cpu(cpu_msrs, i).counters);
+		per_cpu(cpu_msrs, i).counters = NULL;
+		kfree(per_cpu(cpu_msrs, i).controls);
+		per_cpu(cpu_msrs, i).controls = NULL;
 	}
 }
 
@@ -149,13 +149,15 @@ static int allocate_msrs(void)
 
 	int i;
 	for_each_possible_cpu(i) {
-		cpu_msrs[i].counters = kmalloc(counters_size, GFP_KERNEL);
-		if (!cpu_msrs[i].counters) {
+		per_cpu(cpu_msrs, i).counters = kmalloc(counters_size,
+								GFP_KERNEL);
+		if (!per_cpu(cpu_msrs, i).counters) {
 			success = 0;
 			break;
 		}
-		cpu_msrs[i].controls = kmalloc(controls_size, GFP_KERNEL);
-		if (!cpu_msrs[i].controls) {
+		per_cpu(cpu_msrs, i).controls = kmalloc(controls_size,
+								GFP_KERNEL);
+		if (!per_cpu(cpu_msrs, i).controls) {
 			success = 0;
 			break;
 		}
@@ -170,11 +172,11 @@ static int allocate_msrs(void)
 static void nmi_cpu_setup(void *dummy)
 {
 	int cpu = smp_processor_id();
-	struct op_msrs *msrs = &cpu_msrs[cpu];
+	struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
 	spin_lock(&oprofilefs_lock);
 	model->setup_ctrs(msrs);
 	spin_unlock(&oprofilefs_lock);
-	saved_lvtpc[cpu] = apic_read(APIC_LVTPC);
+	per_cpu(saved_lvtpc, cpu) = apic_read(APIC_LVTPC);
 	apic_write(APIC_LVTPC, APIC_DM_NMI);
 }
 
@@ -203,13 +205,15 @@ static int nmi_setup(void)
 	 */
 
 	/* Assume saved/restored counters are the same on all CPUs */
-	model->fill_in_addresses(&cpu_msrs[0]);
+	model->fill_in_addresses(&per_cpu(cpu_msrs, 0));
 	for_each_possible_cpu(cpu) {
 		if (cpu != 0) {
-			memcpy(cpu_msrs[cpu].counters, cpu_msrs[0].counters,
+			memcpy(per_cpu(cpu_msrs, cpu).counters,
+				per_cpu(cpu_msrs, 0).counters,
 				sizeof(struct op_msr) * model->num_counters);
 
-			memcpy(cpu_msrs[cpu].controls, cpu_msrs[0].controls,
+			memcpy(per_cpu(cpu_msrs, cpu).controls,
+				per_cpu(cpu_msrs, 0).controls,
 				sizeof(struct op_msr) * model->num_controls);
 		}
 
@@ -249,7 +253,7 @@ static void nmi_cpu_shutdown(void *dummy
 {
 	unsigned int v;
 	int cpu = smp_processor_id();
-	struct op_msrs *msrs = &cpu_msrs[cpu];
+	struct op_msrs *msrs = &__get_cpu_var(cpu_msrs);
 
 	/* restoring APIC_LVTPC can trigger an apic error because the delivery
 	 * mode and vector nr combination can be illegal. That's by design: on
@@ -258,23 +262,24 @@ static void nmi_cpu_shutdown(void *dummy
 	 */
 	v = apic_read(APIC_LVTERR);
 	apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
-	apic_write(APIC_LVTPC, saved_lvtpc[cpu]);
+	apic_write(APIC_LVTPC, per_cpu(saved_lvtpc, cpu));
 	apic_write(APIC_LVTERR, v);
 	nmi_restore_registers(msrs);
 }
 
 static void nmi_shutdown(void)
 {
+	struct op_msrs *msrs = &__get_cpu_var(cpu_msrs);
 	nmi_enabled = 0;
 	on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1);
 	unregister_die_notifier(&profile_exceptions_nb);
-	model->shutdown(cpu_msrs);
+	model->shutdown(msrs);
 	free_msrs();
 }
 
 static void nmi_cpu_start(void *dummy)
 {
-	struct op_msrs const *msrs = &cpu_msrs[smp_processor_id()];
+	struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
 	model->start(msrs);
 }
 
@@ -286,7 +291,7 @@ static int nmi_start(void)
 
 static void nmi_cpu_stop(void *dummy)
 {
-	struct op_msrs const *msrs = &cpu_msrs[smp_processor_id()];
+	struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
 	model->stop(msrs);
 }
 

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