Commit 2c33645d authored by Palik, Imre's avatar Palik, Imre Committed by Ingo Molnar

perf/x86: Honor the architectural performance monitoring version

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: default avatarImre Palik <imrep@amazon.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Anthony Liguori <aliguori@amazon.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
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: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1433767609-1039-1-git-send-email-imrep.amz@gmail.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 1b7b938f
......@@ -3324,13 +3324,13 @@ __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 != FIXED_EVENT_FLAGS
|| c->idxmsk64 == INTEL_PMC_MSK_FIXED_REF_CYCLES) {
continue;
if (c->cmask == FIXED_EVENT_FLAGS
&& c->idxmsk64 != INTEL_PMC_MSK_FIXED_REF_CYCLES) {
c->idxmsk64 |= (1ULL << x86_pmu.num_counters) - 1;
}
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);
}
}
......
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