src/patches/suse-2.6.27.39/patches.trace/lttng-instrumentation-swap.patch

   1 From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
   2 Subject: LTTng instrumentation - swap
   3
   4 Original patch header:
   5   LTTng instrumentation - swap
   6
   7   Instrumentation of waits caused by swap activity. Also instrumentation
   8   swapon/swapoff events to keep track of active swap partitions.
   9
  10   Those tracepoints are used by LTTng.
  11
  12   About the performance impact of tracepoints (which is comparable to markers),
  13   even without immediate values optimizations, tests done by Hideo Aoki on ia64
  14   show no regression. His test case was using hackbench on a kernel where
  15   scheduler instrumentation (about 5 events in code scheduler code) was added.
  16   See the "Tracepoints" patch header for performance result detail.
  17
  18   Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
  19   CC: linux-mm@kvack.org
  20   CC: Dave Hansen <haveblue@us.ibm.com>
  21   CC: Masami Hiramatsu <mhiramat@redhat.com>
  22   CC: 'Peter Zijlstra' <peterz@infradead.org>
  23   CC: "Frank Ch. Eigler" <fche@redhat.com>
  24   CC: 'Ingo Molnar' <mingo@elte.hu>
  25   CC: 'Hideo AOKI' <haoki@redhat.com>
  26   CC: Takashi Nishiie <t-nishiie@np.css.fujitsu.com>
  27   CC: 'Steven Rostedt' <rostedt@goodmis.org>
  28   CC: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
  29
  30 Acked-by: Jan Blunck <jblunck@suse.de>
  31 ---
  32 ---
  33  include/trace/swap.h |   20 ++++++++++++++++++++
  34  mm/memory.c          |    3 +++
  35  mm/page_io.c         |    2 ++
  36  mm/swapfile.c        |    3 +++
  37  4 files changed, 28 insertions(+)
  38
  39 --- /dev/null
  40 +++ b/include/trace/swap.h
  41 @@ -0,0 +1,20 @@
  42 +#ifndef _TRACE_SWAP_H
  43 +#define _TRACE_SWAP_H
  44 +
  45 +#include <linux/swap.h>
  46 +#include <linux/tracepoint.h>
  47 +
  48 +DEFINE_TRACE(swap_in,
  49 +       TPPROTO(struct page *page, swp_entry_t entry),
  50 +       TPARGS(page, entry));
  51 +DEFINE_TRACE(swap_out,
  52 +       TPPROTO(struct page *page),
  53 +       TPARGS(page));
  54 +DEFINE_TRACE(swap_file_open,
  55 +       TPPROTO(struct file *file, char *filename),
  56 +       TPARGS(file, filename));
  57 +DEFINE_TRACE(swap_file_close,
  58 +       TPPROTO(struct file *file),
  59 +       TPARGS(file));
  60 +
  61 +#endif
  62 --- a/mm/memory.c
  63 +++ b/mm/memory.c
  64 @@ -64,6 +64,8 @@
  65
  66  #include "internal.h"
  67
  68 +#include <trace/swap.h>
  69 +
  70  #ifndef CONFIG_NEED_MULTIPLE_NODES
  71  /* use the per-pgdat data instead for discontigmem - mbligh */
  72  unsigned long max_mapnr;
  73 @@ -2441,6 +2443,7 @@ static int do_swap_page(struct mm_struct
  74                 /* Had to read the page from swap area: Major fault */
  75                 ret = VM_FAULT_MAJOR;
  76                 count_vm_event(PGMAJFAULT);
  77 +               trace_swap_in(page, entry);
  78         }
  79
  80         if (mem_cgroup_charge(page, mm, GFP_KERNEL)) {
  81 --- a/mm/page_io.c
  82 +++ b/mm/page_io.c
  83 @@ -17,6 +17,7 @@
  84  #include <linux/bio.h>
  85  #include <linux/swapops.h>
  86  #include <linux/writeback.h>
  87 +#include <trace/swap.h>
  88  #include <asm/pgtable.h>
  89
  90  static struct bio *get_swap_bio(gfp_t gfp_flags, pgoff_t index,
  91 @@ -114,6 +115,7 @@ int swap_writepage(struct page *page, st
  92                 rw |= (1 << BIO_RW_SYNC);
  93         count_vm_event(PSWPOUT);
  94         set_page_writeback(page);
  95 +       trace_swap_out(page);
  96         unlock_page(page);
  97         submit_bio(rw, bio);
  98  out:
  99 --- a/mm/swapfile.c
 100 +++ b/mm/swapfile.c
 101 @@ -36,6 +36,7 @@
 102  #include <asm/pgtable.h>
 103  #include <asm/tlbflush.h>
 104  #include <linux/swapops.h>
 105 +#include <trace/swap.h>
 106
 107  static DEFINE_SPINLOCK(swap_lock);
 108  static unsigned int nr_swapfiles;
 109 @@ -1325,6 +1326,7 @@ SYSCALL_DEFINE1(swapoff, const char __us
 110         swap_map = p->swap_map;
 111         p->swap_map = NULL;
 112         p->flags = 0;
 113 +       trace_swap_file_close(swap_file);
 114         spin_unlock(&swap_lock);
 115         mutex_unlock(&swapon_mutex);
 116         vfree(swap_map);
 117 @@ -1704,6 +1706,7 @@ SYSCALL_DEFINE2(swapon, const char __use
 118         } else {
 119                 swap_info[prev].next = p - swap_info;
 120         }
 121 +       trace_swap_file_open(swap_file, name);
 122         spin_unlock(&swap_lock);
 123         mutex_unlock(&swapon_mutex);
 124         error = 0;