lkml.org 
[lkml]   [2017]   [May]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] mm,oom: add tracepoints for oom reaper-related events
Date
Add tracepoints to simplify the debugging of the oom reaper code.

Trace the following events:
1) a process is marked as an oom victim,
2) a process is added to the oom reaper list,
3) the oom reaper starts reaping process's mm,
4) the oom reaper finished reaping,
5) the oom reaper skips reaping.

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: kernel-team@fb.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
---
include/trace/events/oom.h | 80 ++++++++++++++++++++++++++++++++++++++++++++++
mm/oom_kill.c | 7 ++++
2 files changed, 87 insertions(+)

diff --git a/include/trace/events/oom.h b/include/trace/events/oom.h
index 38baeb2..c3c19d4 100644
--- a/include/trace/events/oom.h
+++ b/include/trace/events/oom.h
@@ -70,6 +70,86 @@ TRACE_EVENT(reclaim_retry_zone,
__entry->wmark_check)
);

+TRACE_EVENT(mark_victim,
+ TP_PROTO(int pid),
+
+ TP_ARGS(pid),
+
+ TP_STRUCT__entry(
+ __field(int, pid)
+ ),
+
+ TP_fast_assign(
+ __entry->pid = pid;
+ ),
+
+ TP_printk("pid=%d", __entry->pid)
+);
+
+TRACE_EVENT(wake_reaper,
+ TP_PROTO(int pid),
+
+ TP_ARGS(pid),
+
+ TP_STRUCT__entry(
+ __field(int, pid)
+ ),
+
+ TP_fast_assign(
+ __entry->pid = pid;
+ ),
+
+ TP_printk("pid=%d", __entry->pid)
+);
+
+TRACE_EVENT(start_task_reaping,
+ TP_PROTO(int pid),
+
+ TP_ARGS(pid),
+
+ TP_STRUCT__entry(
+ __field(int, pid)
+ ),
+
+ TP_fast_assign(
+ __entry->pid = pid;
+ ),
+
+ TP_printk("pid=%d", __entry->pid)
+);
+
+TRACE_EVENT(finish_task_reaping,
+ TP_PROTO(int pid),
+
+ TP_ARGS(pid),
+
+ TP_STRUCT__entry(
+ __field(int, pid)
+ ),
+
+ TP_fast_assign(
+ __entry->pid = pid;
+ ),
+
+ TP_printk("pid=%d", __entry->pid)
+);
+
+TRACE_EVENT(skip_task_reaping,
+ TP_PROTO(int pid),
+
+ TP_ARGS(pid),
+
+ TP_STRUCT__entry(
+ __field(int, pid)
+ ),
+
+ TP_fast_assign(
+ __entry->pid = pid;
+ ),
+
+ TP_printk("pid=%d", __entry->pid)
+);
+
#ifdef CONFIG_COMPACTION
TRACE_EVENT(compact_retry,

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 04c9143..409b685 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -490,6 +490,7 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)

if (!down_read_trylock(&mm->mmap_sem)) {
ret = false;
+ trace_skip_task_reaping(tsk->pid);
goto unlock_oom;
}

@@ -500,9 +501,12 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
*/
if (!mmget_not_zero(mm)) {
up_read(&mm->mmap_sem);
+ trace_skip_task_reaping(tsk->pid);
goto unlock_oom;
}

+ trace_start_task_reaping(tsk->pid);
+
/*
* Tell all users of get_user/copy_from_user etc... that the content
* is no longer stable. No barriers really needed because unmapping
@@ -544,6 +548,7 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
* put the oom_reaper out of the way.
*/
mmput_async(mm);
+ trace_finish_task_reaping(tsk->pid);
unlock_oom:
mutex_unlock(&oom_lock);
return ret;
@@ -615,6 +620,7 @@ static void wake_oom_reaper(struct task_struct *tsk)
tsk->oom_reaper_list = oom_reaper_list;
oom_reaper_list = tsk;
spin_unlock(&oom_reaper_lock);
+ trace_wake_reaper(tsk->pid);
wake_up(&oom_reaper_wait);
}

@@ -666,6 +672,7 @@ static void mark_oom_victim(struct task_struct *tsk)
*/
__thaw_task(tsk);
atomic_inc(&oom_victims);
+ trace_mark_victim(tsk->pid);
}

/**
--
2.7.4
\
 
 \ /
  Last update: 2017-05-30 14:08    [W:0.222 / U:0.024 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site