Lendacky, Thomas 3966c3feca x86/perf/amd: Remove need to check "running" bit in NMI handler ... Spurious interrupt support was added to perf in the following commit, almost a decade ago: 63e6be6d98 ("perf, x86: Catch spurious interrupts after disabling counters") The two previous patches (resolving the race condition when disabling a PMC and NMI latency mitigation) allow for the removal of this older spurious interrupt support. Currently in x86_pmu_stop(), the bit for the PMC in the active_mask bitmap is cleared before disabling the PMC, which sets up a race condition. This race condition was mitigated by introducing the running bitmap. That race condition can be eliminated by first disabling the PMC, waiting for PMC reset on overflow and then clearing the bit for the PMC in the active_mask bitmap. The NMI handler will not re-enable a disabled counter. If x86_pmu_stop() is called from the perf NMI handler, the NMI latency mitigation support will guard against any unhandled NMI messages. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> # 4.14.x- Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lkml.kernel.org/r/Message-ID: Signed-off-by: Ingo Molnar <mingo@kernel.org>		2019-04-10 13:03:18 +02:00
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amd	x86/perf/amd: Remove need to check "running" bit in NMI handler	2019-04-10 13:03:18 +02:00
intel	perf/x86/intel: Initialize TFA MSR	2019-04-03 11:40:32 +02:00
core.c	x86/perf/amd: Remove need to check "running" bit in NMI handler	2019-04-10 13:03:18 +02:00
Kconfig	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
Makefile	perf/x86/events: Add an AMD-specific Makefile	2017-01-30 12:01:19 +01:00
msr.c	perf/core, arch/x86: Use PERF_PMU_CAP_NO_EXCLUDE for exclusion incapable PMUs	2019-01-21 11:01:27 +01:00
perf_event.h	perf/x86: Fixup typo in stub functions	2019-03-15 13:12:42 +01:00