Peter Zijlstra <pet...@infradead.org> writes: > On Fri, Nov 14, 2014 at 03:43:45PM +0200, Alexander Shishkin wrote: >> +static void pt_event_stop(struct perf_event *event, int mode) >> +{ >> + struct pt *pt = this_cpu_ptr(&pt_ctx); >> + >> + ACCESS_ONCE(pt->handle_nmi) = 0; > > Why is this needed? Will the hardware still generate interrupts if you > stop the PT thing?
It's meant to serialize nmi handler against the pmu:: callbacks, but now you mentioned it, it looks very much redundant. Cheers, -- Alex -- 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/