diff options
| -rw-r--r-- | arch/x86/events/intel/core.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index dff6623804c2..332954cccece 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -1945,6 +1945,14 @@ static __initconst const u64 knl_hw_cache_extra_regs * intel_bts events don't coexist with intel PMU's BTS events because of * x86_add_exclusive(x86_lbr_exclusive_lbr); there's no need to keep them * disabled around intel PMU's event batching etc, only inside the PMI handler. + * + * Avoid PEBS_ENABLE MSR access in PMIs. + * The GLOBAL_CTRL has been disabled. All the counters do not count anymore. + * It doesn't matter if the PEBS is enabled or not. + * Usually, the PEBS status are not changed in PMIs. It's unnecessary to + * access PEBS_ENABLE MSR in disable_all()/enable_all(). + * However, there are some cases which may change PEBS status, e.g. PMI + * throttle. The PEBS_ENABLE should be updated where the status changes. */ static void __intel_pmu_disable_all(void) { @@ -1954,13 +1962,12 @@ static void __intel_pmu_disable_all(void) if (test_bit(INTEL_PMC_IDX_FIXED_BTS, cpuc->active_mask)) intel_pmu_disable_bts(); - - intel_pmu_pebs_disable_all(); } static void intel_pmu_disable_all(void) { __intel_pmu_disable_all(); + intel_pmu_pebs_disable_all(); intel_pmu_lbr_disable_all(); } @@ -1968,7 +1975,6 @@ static void __intel_pmu_enable_all(int added, bool pmi) { struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); - intel_pmu_pebs_enable_all(); intel_pmu_lbr_enable_all(pmi); wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, x86_pmu.intel_ctrl & ~cpuc->intel_ctrl_guest_mask); @@ -1986,6 +1992,7 @@ static void __intel_pmu_enable_all(int added, bool pmi) static void intel_pmu_enable_all(int added) { + intel_pmu_pebs_enable_all(); __intel_pmu_enable_all(added, false); } @@ -2374,9 +2381,21 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status) * PEBS overflow sets bit 62 in the global status register */ if (__test_and_clear_bit(62, (unsigned long *)&status)) { + u64 pebs_enabled = cpuc->pebs_enabled; + handled++; x86_pmu.drain_pebs(regs); status &= x86_pmu.intel_ctrl | GLOBAL_STATUS_TRACE_TOPAPMI; + + /* + * PMI throttle may be triggered, which stops the PEBS event. + * Although cpuc->pebs_enabled is updated accordingly, the + * MSR_IA32_PEBS_ENABLE is not updated. Because the + * cpuc->enabled has been forced to 0 in PMI. + * Update the MSR if pebs_enabled is changed. + */ + if (pebs_enabled != cpuc->pebs_enabled) + wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled); } /* |