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authorRobert Richter <robert.richter@amd.com>2012-04-02 20:19:17 +0200
committerIngo Molnar <mingo@kernel.org>2012-05-09 15:23:16 +0200
commitfc5fb2b5e1874e5894e2ac503bfb744220db89a1 (patch)
tree9f4f3913a971b5a7acb990038dc661da40ecc13b /arch
parentperf/x86-ibs: Implement workaround for IBS erratum #420 (diff)
downloadlinux-fc5fb2b5e1874e5894e2ac503bfb744220db89a1.tar.xz
linux-fc5fb2b5e1874e5894e2ac503bfb744220db89a1.zip
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 <robert.richter@amd.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1333390758-10893-12-git-send-email-robert.richter@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/cpu/perf_event_amd_ibs.c12
1 files changed, 7 insertions, 5 deletions
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;