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authorKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>2012-01-11 00:08:09 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-11 01:30:44 +0100
commit43d2b113241d6797b890318767e0af78e313414b (patch)
tree6f25647f2660f8fca63cc8355b70ad643993dab8 /kernel/fork.c
parentmm: simplify find_vma_prev() (diff)
downloadlinux-43d2b113241d6797b890318767e0af78e313414b.tar.xz
linux-43d2b113241d6797b890318767e0af78e313414b.zip
tracepoint: add tracepoints for debugging oom_score_adj
oom_score_adj is used for guarding processes from OOM-Killer. One of problem is that it's inherited at fork(). When a daemon set oom_score_adj and make children, it's hard to know where the value is set. This patch adds some tracepoints useful for debugging. This patch adds 3 trace points. - creating new task - renaming a task (exec) - set oom_score_adj To debug, users need to enable some trace pointer. Maybe filtering is useful as # EVENT=/sys/kernel/debug/tracing/events/task/ # echo "oom_score_adj != 0" > $EVENT/task_newtask/filter # echo "oom_score_adj != 0" > $EVENT/task_rename/filter # echo 1 > $EVENT/enable # EVENT=/sys/kernel/debug/tracing/events/oom/ # echo 1 > $EVENT/enable output will be like this. # grep oom /sys/kernel/debug/tracing/trace bash-7699 [007] d..3 5140.744510: oom_score_adj_update: pid=7699 comm=bash oom_score_adj=-1000 bash-7699 [007] ...1 5151.818022: task_newtask: pid=7729 comm=bash clone_flags=1200011 oom_score_adj=-1000 ls-7729 [003] ...2 5151.818504: task_rename: pid=7729 oldcomm=bash newcomm=ls oom_score_adj=-1000 bash-7699 [002] ...1 5175.701468: task_newtask: pid=7730 comm=bash clone_flags=1200011 oom_score_adj=-1000 grep-7730 [007] ...2 5175.701993: task_rename: pid=7730 oldcomm=bash newcomm=grep oom_score_adj=-1000 Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index b00711ce7c13..5e1391b5ade0 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -76,6 +76,9 @@
#include <trace/events/sched.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/task.h>
+
/*
* Protected counters by write_lock_irq(&tasklist_lock)
*/
@@ -1370,6 +1373,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
if (clone_flags & CLONE_THREAD)
threadgroup_change_end(current);
perf_event_fork(p);
+
+ trace_task_newtask(p, clone_flags);
+
return p;
bad_fork_free_pid: