mm: trace filemap add and del

Use the events API to trace filemap loading and unloading of file pieces
into the page cache.

This patch aims at tracing the eviction reload cycle of executable and
shared libraries pages in a memory constrained environment.

The typical usage is to spot a specific device and inode (for example
/lib/libc.so) to see the eviction cycles, and find out if frequently
used code is rather spread across many pages (bad) or coallesced (good).

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Robert Jarzmik
2013-04-29 15:06:10 -07:00
committed by Linus Torvalds
parent e39862958d
commit fe0bfaaff8
2 changed files with 63 additions and 0 deletions

View File

@@ -0,0 +1,58 @@
#undef TRACE_SYSTEM
#define TRACE_SYSTEM filemap
#if !defined(_TRACE_FILEMAP_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_FILEMAP_H
#include <linux/types.h>
#include <linux/tracepoint.h>
#include <linux/mm.h>
#include <linux/memcontrol.h>
#include <linux/device.h>
#include <linux/kdev_t.h>
DECLARE_EVENT_CLASS(mm_filemap_op_page_cache,
TP_PROTO(struct page *page),
TP_ARGS(page),
TP_STRUCT__entry(
__field(struct page *, page)
__field(unsigned long, i_ino)
__field(unsigned long, index)
__field(dev_t, s_dev)
),
TP_fast_assign(
__entry->page = page;
__entry->i_ino = page->mapping->host->i_ino;
__entry->index = page->index;
if (page->mapping->host->i_sb)
__entry->s_dev = page->mapping->host->i_sb->s_dev;
else
__entry->s_dev = page->mapping->host->i_rdev;
),
TP_printk("dev %d:%d ino %lx page=%p pfn=%lu ofs=%lu",
MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
__entry->i_ino,
__entry->page,
page_to_pfn(__entry->page),
__entry->index << PAGE_SHIFT)
);
DEFINE_EVENT(mm_filemap_op_page_cache, mm_filemap_delete_from_page_cache,
TP_PROTO(struct page *page),
TP_ARGS(page)
);
DEFINE_EVENT(mm_filemap_op_page_cache, mm_filemap_add_to_page_cache,
TP_PROTO(struct page *page),
TP_ARGS(page)
);
#endif /* _TRACE_FILEMAP_H */
/* This part must be outside protection */
#include <trace/define_trace.h>