linux/include/trace/events/task.h
KAMEZAWA Hiroyuki 43d2b11324 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>
2012-01-10 16:30:44 -08:00

62 lines
1.4 KiB
C

#undef TRACE_SYSTEM
#define TRACE_SYSTEM task
#if !defined(_TRACE_TASK_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_TASK_H
#include <linux/tracepoint.h>
TRACE_EVENT(task_newtask,
TP_PROTO(struct task_struct *task, unsigned long clone_flags),
TP_ARGS(task, clone_flags),
TP_STRUCT__entry(
__field( pid_t, pid)
__array( char, comm, TASK_COMM_LEN)
__field( unsigned long, clone_flags)
__field( int, oom_score_adj)
),
TP_fast_assign(
__entry->pid = task->pid;
memcpy(__entry->comm, task->comm, TASK_COMM_LEN);
__entry->clone_flags = clone_flags;
__entry->oom_score_adj = task->signal->oom_score_adj;
),
TP_printk("pid=%d comm=%s clone_flags=%lx oom_score_adj=%d",
__entry->pid, __entry->comm,
__entry->clone_flags, __entry->oom_score_adj)
);
TRACE_EVENT(task_rename,
TP_PROTO(struct task_struct *task, char *comm),
TP_ARGS(task, comm),
TP_STRUCT__entry(
__field( pid_t, pid)
__array( char, oldcomm, TASK_COMM_LEN)
__array( char, newcomm, TASK_COMM_LEN)
__field( int, oom_score_adj)
),
TP_fast_assign(
__entry->pid = task->pid;
memcpy(entry->oldcomm, task->comm, TASK_COMM_LEN);
memcpy(entry->newcomm, comm, TASK_COMM_LEN);
__entry->oom_score_adj = task->signal->oom_score_adj;
),
TP_printk("pid=%d oldcomm=%s newcomm=%s oom_score_adj=%d",
__entry->pid, __entry->oldcomm,
__entry->newcomm, __entry->oom_score_adj)
);
#endif
/* This part must be outside protection */
#include <trace/define_trace.h>