From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: <20080325021954.979158000@polaris-admin.engr.sgi.com> Date: Mon, 24 Mar 2008 19:19:54 -0700 From: Mike Travis Subject: [PATCH 00/10] NR_CPUS: third reduction of NR_CPUS memory usage Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: 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 Cc: Andi Kleen Cc: Anton Blanchard Cc: Christoph Lameter Cc: Dave Jones Cc: David S. Miller Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Ingo Molnar Cc: James Morris Cc: Len Brown Cc: Patrick McHardy Cc: Paul Jackson Cc: Paul Mackerras Cc: Philippe Elie Cc: Thomas Gleixner Cc: Tony Luck Cc: William L. Irwin Signed-off-by: Mike Travis --- 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 -- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org