[patch 08/15] LTTng instrumentation - filemap

[patch 08/15] LTTng instrumentation - filemap

[Mathieu Desnoyers]

[-- Attachment #1: lttng-instrumentation-filemap.patch --]
[-- Type: text/plain, Size: 2815 bytes --]

Instrumentation of waits caused by memory accesses on mmap regions.

Those tracepoints are used by LTTng.

About the performance impact of tracepoints (which is comparable to markers),
even without immediate values optimizations, tests done by Hideo Aoki on ia64
show no regression. His test case was using hackbench on a kernel where
scheduler instrumentation (about 5 events in code scheduler code) was added.
See the "Tracepoints" patch header for performance result detail.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: linux-mm@kvack.org
CC: Dave Hansen <haveblue@us.ibm.com>
CC: Masami Hiramatsu <mhiramat@redhat.com>
CC: 'Peter Zijlstra' <peterz@infradead.org>
CC: "Frank Ch. Eigler" <fche@redhat.com>
CC: 'Ingo Molnar' <mingo@elte.hu>
CC: 'Hideo AOKI' <haoki@redhat.com>
CC: Takashi Nishiie <t-nishiie@np.css.fujitsu.com>
CC: 'Steven Rostedt' <rostedt@goodmis.org>
CC: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
---
 mm/filemap-trace.h |   13 +++++++++++++
 mm/filemap.c       |    3 +++
 2 files changed, 16 insertions(+)

Index: linux-2.6-lttng/mm/filemap.c
===================================================================
--- linux-2.6-lttng.orig/mm/filemap.c	2008-07-09 10:55:46.000000000 -0400
+++ linux-2.6-lttng/mm/filemap.c	2008-07-09 10:58:27.000000000 -0400
@@ -33,6 +33,7 @@
 #include <linux/cpuset.h>
 #include <linux/hardirq.h> /* for BUG_ON(!in_atomic()) only */
 #include <linux/memcontrol.h>
+#include "filemap-trace.h"
 #include "internal.h"
 
 /*
@@ -541,9 +542,11 @@ void wait_on_page_bit(struct page *page,
 {
 	DEFINE_WAIT_BIT(wait, &page->flags, bit_nr);
 
+	trace_filemap_wait_start(page, bit_nr);
 	if (test_bit(bit_nr, &page->flags))
 		__wait_on_bit(page_waitqueue(page), &wait, sync_page,
 							TASK_UNINTERRUPTIBLE);
+	trace_filemap_wait_end(page, bit_nr);
 }
 EXPORT_SYMBOL(wait_on_page_bit);
 
Index: linux-2.6-lttng/mm/filemap-trace.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6-lttng/mm/filemap-trace.h	2008-07-09 10:58:27.000000000 -0400
@@ -0,0 +1,13 @@
+#ifndef _FILEMAP_TRACE_H
+#define _FILEMAP_TRACE_H
+
+#include <linux/tracepoint.h>
+
+DEFINE_TRACE(filemap_wait_start,
+	TPPROTO(struct page *page, int bit_nr),
+	TPARGS(page, bit_nr));
+DEFINE_TRACE(filemap_wait_end,
+	TPPROTO(struct page *page, int bit_nr),
+	TPARGS(page, bit_nr));
+
+#endif

-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68

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[patch 09/15] LTTng instrumentation - swap

[Mathieu Desnoyers]

[-- Attachment #1: lttng-instrumentation-swap.patch --]
[-- Type: text/plain, Size: 4775 bytes --]

Instrumentation of waits caused by swap activity. Also instrumentation
swapon/swapoff events to keep track of active swap partitions.

Those tracepoints are used by LTTng.

About the performance impact of tracepoints (which is comparable to markers),
even without immediate values optimizations, tests done by Hideo Aoki on ia64
show no regression. His test case was using hackbench on a kernel where
scheduler instrumentation (about 5 events in code scheduler code) was added.
See the "Tracepoints" patch header for performance result detail.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: linux-mm@kvack.org
CC: Dave Hansen <haveblue@us.ibm.com>
CC: Masami Hiramatsu <mhiramat@redhat.com>
CC: 'Peter Zijlstra' <peterz@infradead.org>
CC: "Frank Ch. Eigler" <fche@redhat.com>
CC: 'Ingo Molnar' <mingo@elte.hu>
CC: 'Hideo AOKI' <haoki@redhat.com>
CC: Takashi Nishiie <t-nishiie@np.css.fujitsu.com>
CC: 'Steven Rostedt' <rostedt@goodmis.org>
CC: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
---
 mm/memory.c     |    2 ++
 mm/page_io.c    |    2 ++
 mm/swap-trace.h |   20 ++++++++++++++++++++
 mm/swapfile.c   |    4 ++++
 4 files changed, 28 insertions(+)

Index: linux-2.6-lttng/mm/memory.c
===================================================================
--- linux-2.6-lttng.orig/mm/memory.c	2008-07-09 10:46:33.000000000 -0400
+++ linux-2.6-lttng/mm/memory.c	2008-07-09 10:58:31.000000000 -0400
@@ -51,6 +51,7 @@
 #include <linux/init.h>
 #include <linux/writeback.h>
 #include <linux/memcontrol.h>
+#include "swap-trace.h"
 
 #include <asm/pgalloc.h>
 #include <asm/uaccess.h>
@@ -2213,6 +2214,7 @@ static int do_swap_page(struct mm_struct
 		/* Had to read the page from swap area: Major fault */
 		ret = VM_FAULT_MAJOR;
 		count_vm_event(PGMAJFAULT);
+		trace_swap_in(page, entry);
 	}
 
 	if (mem_cgroup_charge(page, mm, GFP_KERNEL)) {
Index: linux-2.6-lttng/mm/page_io.c
===================================================================
--- linux-2.6-lttng.orig/mm/page_io.c	2008-07-09 10:46:33.000000000 -0400
+++ linux-2.6-lttng/mm/page_io.c	2008-07-09 10:58:31.000000000 -0400
@@ -17,6 +17,7 @@
 #include <linux/bio.h>
 #include <linux/swapops.h>
 #include <linux/writeback.h>
+#include "swap-trace.h"
 #include <asm/pgtable.h>
 
 static struct bio *get_swap_bio(gfp_t gfp_flags, pgoff_t index,
@@ -114,6 +115,7 @@ int swap_writepage(struct page *page, st
 		rw |= (1 << BIO_RW_SYNC);
 	count_vm_event(PSWPOUT);
 	set_page_writeback(page);
+	trace_swap_out(page);
 	unlock_page(page);
 	submit_bio(rw, bio);
 out:
Index: linux-2.6-lttng/mm/swapfile.c
===================================================================
--- linux-2.6-lttng.orig/mm/swapfile.c	2008-07-09 10:46:33.000000000 -0400
+++ linux-2.6-lttng/mm/swapfile.c	2008-07-09 10:58:31.000000000 -0400
@@ -32,6 +32,7 @@
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
 #include <linux/swapops.h>
+#include "swap-trace.h"
 
 DEFINE_SPINLOCK(swap_lock);
 unsigned int nr_swapfiles;
@@ -1310,6 +1311,7 @@ asmlinkage long sys_swapoff(const char _
 	swap_map = p->swap_map;
 	p->swap_map = NULL;
 	p->flags = 0;
+	trace_swap_file_close(swap_file);
 	spin_unlock(&swap_lock);
 	mutex_unlock(&swapon_mutex);
 	vfree(swap_map);
@@ -1695,6 +1697,7 @@ asmlinkage long sys_swapon(const char __
 	} else {
 		swap_info[prev].next = p - swap_info;
 	}
+	trace_swap_file_open(swap_file, name);
 	spin_unlock(&swap_lock);
 	mutex_unlock(&swapon_mutex);
 	error = 0;
@@ -1796,6 +1799,7 @@ get_swap_info_struct(unsigned type)
 {
 	return &swap_info[type];
 }
+EXPORT_SYMBOL_GPL(get_swap_info_struct);
 
 /*
  * swap_lock prevents swap_map being freed. Don't grab an extra
Index: linux-2.6-lttng/mm/swap-trace.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6-lttng/mm/swap-trace.h	2008-07-09 10:58:31.000000000 -0400
@@ -0,0 +1,20 @@
+#ifndef _SWAP_TRACE_H
+#define _SWAP_TRACE_H
+
+#include <linux/swap.h>
+#include <linux/tracepoint.h>
+
+DEFINE_TRACE(swap_in,
+	TPPROTO(struct page *page, swp_entry_t entry),
+	TPARGS(page, entry));
+DEFINE_TRACE(swap_out,
+	TPPROTO(struct page *page),
+	TPARGS(page));
+DEFINE_TRACE(swap_file_open,
+	TPPROTO(struct file *file, char *filename),
+	TPARGS(file, filename));
+DEFINE_TRACE(swap_file_close,
+	TPPROTO(struct file *file),
+	TPARGS(file));
+
+#endif

-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68

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To unsubscribe, send a message with 'unsubscribe linux-mm' in
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[patch 10/15] LTTng instrumentation - memory page faults

[Mathieu Desnoyers]

[-- Attachment #1: lttng-instrumentation-memory.patch --]
[-- Type: text/plain, Size: 3865 bytes --]

Instrument the page fault entry and exit. Useful to detect delays caused by page
faults and bad memory usage patterns.

Those tracepoints are used by LTTng.

About the performance impact of tracepoints (which is comparable to markers),
even without immediate values optimizations, tests done by Hideo Aoki on ia64
show no regression. His test case was using hackbench on a kernel where
scheduler instrumentation (about 5 events in code scheduler code) was added.
See the "Tracepoints" patch header for performance result detail.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: Andi Kleen <ak@suse.de>
CC: linux-mm@kvack.org
CC: Dave Hansen <haveblue@us.ibm.com>
CC: Masami Hiramatsu <mhiramat@redhat.com>
CC: 'Peter Zijlstra' <peterz@infradead.org>
CC: "Frank Ch. Eigler" <fche@redhat.com>
CC: 'Ingo Molnar' <mingo@elte.hu>
CC: 'Hideo AOKI' <haoki@redhat.com>
CC: Takashi Nishiie <t-nishiie@np.css.fujitsu.com>
CC: 'Steven Rostedt' <rostedt@goodmis.org>
CC: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
---
 mm/memory-trace.h |   14 ++++++++++++++
 mm/memory.c       |   33 ++++++++++++++++++++++++---------
 2 files changed, 38 insertions(+), 9 deletions(-)

Index: linux-2.6-lttng/mm/memory.c
===================================================================
--- linux-2.6-lttng.orig/mm/memory.c	2008-07-09 10:58:31.000000000 -0400
+++ linux-2.6-lttng/mm/memory.c	2008-07-09 10:58:34.000000000 -0400
@@ -61,6 +61,7 @@
 
 #include <linux/swapops.h>
 #include <linux/elf.h>
+#include "memory-trace.h"
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 /* use the per-pgdat data instead for discontigmem - mbligh */
@@ -2664,30 +2665,44 @@ unlock:
 int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 		unsigned long address, int write_access)
 {
+	int res;
 	pgd_t *pgd;
 	pud_t *pud;
 	pmd_t *pmd;
 	pte_t *pte;
 
+	trace_memory_handle_fault_entry(mm, vma, address, write_access);
+
 	__set_current_state(TASK_RUNNING);
 
 	count_vm_event(PGFAULT);
 
-	if (unlikely(is_vm_hugetlb_page(vma)))
-		return hugetlb_fault(mm, vma, address, write_access);
+	if (unlikely(is_vm_hugetlb_page(vma))) {
+		res = hugetlb_fault(mm, vma, address, write_access);
+		goto end;
+	}
 
 	pgd = pgd_offset(mm, address);
 	pud = pud_alloc(mm, pgd, address);
-	if (!pud)
-		return VM_FAULT_OOM;
+	if (!pud) {
+		res = VM_FAULT_OOM;
+		goto end;
+	}
 	pmd = pmd_alloc(mm, pud, address);
-	if (!pmd)
-		return VM_FAULT_OOM;
+	if (!pmd) {
+		res = VM_FAULT_OOM;
+		goto end;
+	}
 	pte = pte_alloc_map(mm, pmd, address);
-	if (!pte)
-		return VM_FAULT_OOM;
+	if (!pte) {
+		res = VM_FAULT_OOM;
+		goto end;
+	}
 
-	return handle_pte_fault(mm, vma, address, pte, pmd, write_access);
+	res = handle_pte_fault(mm, vma, address, pte, pmd, write_access);
+end:
+	trace_memory_handle_fault_exit(res);
+	return res;
 }
 
 #ifndef __PAGETABLE_PUD_FOLDED
Index: linux-2.6-lttng/mm/memory-trace.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6-lttng/mm/memory-trace.h	2008-07-09 10:58:34.000000000 -0400
@@ -0,0 +1,14 @@
+#ifndef _MEMORY_TRACE_H
+#define _MEMORY_TRACE_H
+
+#include <linux/tracepoint.h>
+
+DEFINE_TRACE(memory_handle_fault_entry,
+	TPPROTO(struct mm_struct *mm, struct vm_area_struct *vma,
+		unsigned long address, int write_access),
+	TPARGS(mm, vma, address, write_access));
+DEFINE_TRACE(memory_handle_fault_exit,
+	TPPROTO(int res),
+	TPARGS(res));
+
+#endif

-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68

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To unsubscribe, send a message with 'unsubscribe linux-mm' in
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