On Mon, Oct 12, 2015 at 09:02:42AM +0000, Kaixu Xia wrote: > --- a/include/linux/perf_event.h > +++ b/include/linux/perf_event.h > @@ -483,6 +483,8 @@ struct perf_event { > perf_overflow_handler_t overflow_handler; > void *overflow_handler_context; > > + atomic_t *sample_disable; > + > #ifdef CONFIG_EVENT_TRACING > struct trace_event_call *tp_event; > struct event_filter *filter;
> diff --git a/kernel/events/core.c b/kernel/events/core.c > index b11756f..f6ef45c 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -6337,6 +6337,9 @@ static int __perf_event_overflow(struct perf_event > *event, > irq_work_queue(&event->pending); > } > > + if ((event->sample_disable) && atomic_read(event->sample_disable)) > + return ret; > + > if (event->overflow_handler) > event->overflow_handler(event, data, regs); > else Try and guarantee sample_disable lives in the same cacheline as overflow_handler. I think we should at the very least replace the kzalloc() currently used with a cacheline aligned alloc, and check the structure layout to verify these two do in fact share a cacheline. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/