forgot to CC Stephane jirka
--- hi, I'm getting following warning when running basic cgroup perf stuff: (perf stat -a -e faults -G krava -- sleep 10) WARNING: at kernel/events/core.c:397 perf_cgroup_switch+0x1c6/0x1e0() Hardware name: Montevina platform Modules linked in: Pid: 1173, comm: bash Not tainted 3.6.0+ #129 Call Trace: [<ffffffff8103736f>] warn_slowpath_common+0x7f/0xc0 [<ffffffff810dc025>] ? perf_ctx_lock+0x15/0x30 [<ffffffff810373ca>] warn_slowpath_null+0x1a/0x20 [<ffffffff810e0b96>] perf_cgroup_switch+0x1c6/0x1e0 [<ffffffff810e09d0>] ? perf_event_context_sched_in+0xc0/0xc0 [<ffffffff810e0fa9>] __perf_event_task_sched_in+0xa9/0x200 [<ffffffff81089c67>] ? lock_release_holdtime.part.3+0xc7/0x160 [<ffffffff810689f8>] finish_task_switch+0xb8/0xf0 [<ffffffff814fab2b>] __schedule+0x2eb/0x930 [<ffffffff814fca10>] ? _raw_spin_unlock_irq+0x30/0x60 [<ffffffff8108fd75>] ? trace_hardirqs_on_caller+0x105/0x190 [<ffffffff8108fe0d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff814fca1b>] ? _raw_spin_unlock_irq+0x3b/0x60 [<ffffffff81055238>] ? start_flush_work+0x108/0x180 [<ffffffff814fb289>] schedule+0x29/0x70 [<ffffffff814f8725>] schedule_timeout+0x1c5/0x210 [<ffffffff8105cecd>] ? add_wait_queue+0x4d/0x60 [<ffffffff814fc9c5>] ? _raw_spin_unlock_irqrestore+0x65/0x80 [<ffffffff8108fd75>] ? trace_hardirqs_on_caller+0x105/0x190 [<ffffffff8108fe0d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff814fc9a2>] ? _raw_spin_unlock_irqrestore+0x42/0x80 [<ffffffff812b5151>] n_tty_read+0x461/0x8b0 [<ffffffff8106d040>] ? try_to_wake_up+0x310/0x310 [<ffffffff812af2b9>] tty_read+0x99/0xf0 [<ffffffff81128fff>] vfs_read+0xaf/0x180 [<ffffffff8112911d>] sys_read+0x4d/0x90 [<ffffffff81504412>] system_call_fastpath+0x16/0x1b Looking at the code the cpuctx->cgrp condition seems legal, and need just some adjustment. However, I don't fully understand that code and could be wrong.. just want to get rid of probably wrong warning.. ;) thanks, jirka --- Changing WARN_ON_ONCE condition for PERF_CGROUP_SWIN leg. It's legal to have cpuctx->cgrp already defined, but it's not legal not to have events active at the same time. Cc: Peter Zijlstra <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> CC: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: Jiri Olsa <[email protected]> --- kernel/events/core.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 7b9df35..733f794 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -394,7 +394,8 @@ void perf_cgroup_switch(struct task_struct *task, int mode) } if (mode & PERF_CGROUP_SWIN) { - WARN_ON_ONCE(cpuctx->cgrp); + WARN_ON_ONCE(cpuctx->cgrp && !cpuctx->ctx.is_active); + /* set cgrp before ctxsw in to * allow event_filter_match() to not * have to pass task around -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
