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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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1b7b938f18
Intel PT is a separate PMU and it is not using any of the x86_pmu code paths, which means in particular that the active_events counter remains intact when new PT events are created. However, PT uses the generic x86_pmu PMI handler for its PMI handling needs. The problem here is that the latter checks active_events and in case of it being zero, exits without calling the actual x86_pmu.handle_nmi(), which results in unknown NMI errors and massive data loss for PT. The effect is not visible if there are other perf events in the system at the same time that keep active_events counter non-zero, for instance if the NMI watchdog is running, so one needs to disable it to reproduce the problem. At the same time, the active_events counter besides doing what the name suggests also implicitly serves as a PMC hardware and DS area reference counter. This patch adds a separate reference counter for the PMC hardware, leaving active_events for actually counting the events and makes sure it also counts PT and BTS events. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@infradead.org Cc: adrian.hunter@intel.com Link: http://lkml.kernel.org/r/87k2v92t0s.fsf@ashishki-desk.ger.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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| .. | ||
| mcheck | ||
| microcode | ||
| mtrr | ||
| .gitignore | ||
| amd.c | ||
| bugs_64.c | ||
| bugs.c | ||
| centaur.c | ||
| common.c | ||
| cpu.h | ||
| cyrix.c | ||
| hypervisor.c | ||
| intel_cacheinfo.c | ||
| intel_pt.h | ||
| intel.c | ||
| Makefile | ||
| match.c | ||
| mkcapflags.sh | ||
| mshyperv.c | ||
| perf_event_amd_ibs.c | ||
| perf_event_amd_iommu.c | ||
| perf_event_amd_iommu.h | ||
| perf_event_amd_uncore.c | ||
| perf_event_amd.c | ||
| perf_event_intel_bts.c | ||
| perf_event_intel_cqm.c | ||
| perf_event_intel_ds.c | ||
| perf_event_intel_lbr.c | ||
| perf_event_intel_pt.c | ||
| perf_event_intel_rapl.c | ||
| perf_event_intel_uncore_nhmex.c | ||
| perf_event_intel_uncore_snb.c | ||
| perf_event_intel_uncore_snbep.c | ||
| perf_event_intel_uncore.c | ||
| perf_event_intel_uncore.h | ||
| perf_event_intel.c | ||
| perf_event_knc.c | ||
| perf_event_p4.c | ||
| perf_event_p6.c | ||
| perf_event.c | ||
| perf_event.h | ||
| perfctr-watchdog.c | ||
| powerflags.c | ||
| proc.c | ||
| rdrand.c | ||
| scattered.c | ||
| topology.c | ||
| transmeta.c | ||
| umc.c | ||
| vmware.c | ||