diff options
| author | KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> | 2009-03-13 09:03:04 +0900 |
|---|---|---|
| committer | Steven Rostedt <srostedt@redhat.com> | 2009-03-12 21:23:47 -0400 |
| commit | 889a6c367283709a80dad9413488472596a1a1d2 (patch) | |
| tree | fabe1614e30f9d6e306376159a05e91721b6cb60 /kernel/trace/trace_workqueue.c | |
| parent | 39842323ceb368d2ea36ab7696aedbe296e13b61 (diff) | |
tracing: Don't use tracing_record_cmdline() in workqueue tracer fix
commit c3ffc7a40b7e94b094efe1c8ab4e24370a782b65
"Don't use tracing_record_cmdline() in workqueue tracer"
has a race window.
find_task_by_vpid() requires task_list_lock().
LKML-Reference: <20090313090042.43CD.A69D9226@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Diffstat (limited to 'kernel/trace/trace_workqueue.c')
| -rw-r--r-- | kernel/trace/trace_workqueue.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/kernel/trace/trace_workqueue.c b/kernel/trace/trace_workqueue.c index fb5ccac8bbc0..9ab035b58cf1 100644 --- a/kernel/trace/trace_workqueue.c +++ b/kernel/trace/trace_workqueue.c @@ -193,12 +193,20 @@ static int workqueue_stat_show(struct seq_file *s, void *p) struct cpu_workqueue_stats *cws = p; unsigned long flags; int cpu = cws->cpu; - struct task_struct *tsk = find_task_by_vpid(cws->pid); - - seq_printf(s, "%3d %6d %6u %s\n", cws->cpu, - atomic_read(&cws->inserted), - cws->executed, - tsk ? tsk->comm : "<...>"); + struct pid *pid; + struct task_struct *tsk; + + pid = find_get_pid(cws->pid); + if (pid) { + tsk = get_pid_task(pid, PIDTYPE_PID); + if (tsk) { + seq_printf(s, "%3d %6d %6u %s\n", cws->cpu, + atomic_read(&cws->inserted), cws->executed, + tsk->comm); + put_task_struct(tsk); + } + put_pid(pid); + } spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags); if (&cws->list == workqueue_cpu_stat(cpu)->list.next) |