From: Robert Richter Date: Mon, 2 Apr 2012 18:19:17 +0000 (+0200) Subject: perf/x86-ibs: Catch spurious interrupts after stopping IBS X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=fc5fb2b5e1874e5894e2ac503bfb744220db89a1;p=deliverable%2Flinux.git perf/x86-ibs: Catch spurious interrupts after stopping IBS After disabling IBS there could be still incomming NMIs with samples that even have the valid bit cleared. Mark all this NMIs as handled to avoid spurious interrupt messages. Signed-off-by: Robert Richter Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1333390758-10893-12-git-send-email-robert.richter@amd.com Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/kernel/cpu/perf_event_amd_ibs.c b/arch/x86/kernel/cpu/perf_event_amd_ibs.c index b14e71127c82..5a9f95b5cc26 100644 --- a/arch/x86/kernel/cpu/perf_event_amd_ibs.c +++ b/arch/x86/kernel/cpu/perf_event_amd_ibs.c @@ -473,11 +473,13 @@ static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs) u64 *buf, *config, period; if (!test_bit(IBS_STARTED, pcpu->state)) { - /* Catch spurious interrupts after stopping IBS: */ - if (!test_and_clear_bit(IBS_STOPPING, pcpu->state)) - return 0; - rdmsrl(perf_ibs->msr, *ibs_data.regs); - return (*ibs_data.regs & perf_ibs->valid_mask) ? 1 : 0; + /* + * Catch spurious interrupts after stopping IBS: After + * disabling IBS there could be still incomming NMIs + * with samples that even have the valid bit cleared. + * Mark all this NMIs as handled. + */ + return test_and_clear_bit(IBS_STOPPING, pcpu->state) ? 1 : 0; } msr = hwc->config_base;