On Thu, 19 Feb 2015, Peter Zijlstra wrote:
> On Thu, Feb 19, 2015 at 11:54:40AM -0500, Vince Weaver wrote:
>
> > [ 7938.802139] [<ffffffff8115e114>] perf_tp_event+0xc4/0x210
> > [ 7938.861174] [<ffffffff810b4f8a>] perf_trace_lock+0x12a/0x160
> > [ 7938.882197] [<ffffffff810b7f10>] lock_release+0x130/0x260
> > [ 7938.888754] [<ffffffff816c7474>] _raw_spin_unlock_irqrestore+0x24/0x40
> > [ 7938.896510] [<ffffffff8107bb4d>] do_send_sig_info+0x5d/0x80
> > [ 7938.903240] [<ffffffff811f69df>] send_sigio_to_task+0x12f/0x1a0
> > [ 7938.923894] [<ffffffff811f71ce>] send_sigio+0xae/0x100
> > [ 7938.930132] [<ffffffff811f72b7>] kill_fasync+0x97/0xf0
> > [ 7938.942707] [<ffffffff8115d0b4>] perf_event_wakeup+0xd4/0xf0
> > [ 7938.956367] [<ffffffff8115d103>] perf_pending_event+0x33/0x60
> > [ 7938.963199] [<ffffffff8114e3fc>] irq_work_run_list+0x4c/0x80
> > [ 7938.969932] [<ffffffff8114e448>] irq_work_run+0x18/0x40
> > [ 7938.976212] [<ffffffff810196af>] smp_trace_irq_work_interrupt+0x3f/0xc0
> > [ 7938.983957] [<ffffffff816c99bd>] trace_irq_work_interrupt+0x6d/0x80
>
> Ah, it looks like the never ending irq_work..
>
> Could you try this?
sorry for the delay. I managed to reproduce this problem again on 4.0-rc1,
verified it was reproducible, then applied the patch below and I could no
longer trigger the issue.
Tested-by: Vince Weaver <vincent.wea...@maine.edu>
>
> ---
> kernel/events/core.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index f04daabfd1cf..088e81ae43cb 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -4574,6 +4574,13 @@ static void perf_pending_event(struct irq_work *entry)
> {
> struct perf_event *event = container_of(entry,
> struct perf_event, pending);
> + int rctx;
> +
> + rctx = perf_swevent_get_recursion_context();
> + /*
> + * If we 'fail' here, that's OK, it means recursion is already disabled
> + * and we won't recurse 'further'.
> + */
>
> if (event->pending_disable) {
> event->pending_disable = 0;
> @@ -4584,6 +4591,9 @@ static void perf_pending_event(struct irq_work *entry)
> event->pending_wakeup = 0;
> perf_event_wakeup(event);
> }
> +
> + if (rctx >= 0)
> + perf_swevent_put_recursion_context(rctx);
> }
>
> /*
--
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