From: "Palik, Imre" <[email protected]> commit 2c33645d366d13b969d936b68b9f4875b1fdddea upstream.
Architectural performance monitoring, version 1, doesn't support fixed counters. Currently, even if a hypervisor advertises support for architectural performance monitoring version 1, perf may still try to use the fixed counters, as the constraints are set up based on the CPU model. This patch ensures that perf honors the architectural performance monitoring version returned by CPUID, and it only uses the fixed counters for version 2 and above. (Some of the ideas in this patch came from Peter Zijlstra.) Signed-off-by: Imre Palik <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Anthony Liguori <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> [wt: FIXED_EVENT_FLAGS was X86_RAW_EVENT_MASK in 3.10] Cc: Kevin Christopher <[email protected]> Signed-off-by: Willy Tarreau <[email protected]> --- arch/x86/kernel/cpu/perf_event_intel.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index ac05758..bfc6bb5 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -2241,13 +2241,16 @@ __init int intel_pmu_init(void) * counter, so do not extend mask to generic counters */ for_each_event_constraint(c, x86_pmu.event_constraints) { - if (c->cmask != X86_RAW_EVENT_MASK - || c->idxmsk64 == INTEL_PMC_MSK_FIXED_REF_CYCLES) { + if (c->cmask == X86_RAW_EVENT_MASK + && c->idxmsk64 == INTEL_PMC_MSK_FIXED_REF_CYCLES) { + c->idxmsk64 |= (1ULL << x86_pmu.num_counters) - 1; continue; } - c->idxmsk64 |= (1ULL << x86_pmu.num_counters) - 1; - c->weight += x86_pmu.num_counters; + c->idxmsk64 &= + ~(~0UL << (INTEL_PMC_IDX_FIXED + x86_pmu.num_counters_fixed)); + c->weight = hweight64(c->idxmsk64); + } } -- 2.8.0.rc2.1.gbe9624a
