| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 025/124] perf/x86/intel/uncore: Correct fixed counter index check for NHM | Date | Sat, 4 Aug 2018 11:00:14 +0200 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Kan Liang <kan.liang@intel.com>
[ Upstream commit d71f11c076c420c4e2fceb4faefa144e055e0935 ]
For Nehalem and Westmere, there is only one fixed counter for W-Box. There is no index which is bigger than UNCORE_PMC_IDX_FIXED. It is not correct to use >= to check fixed counter. The code quality issue will bring problem when new counter index is introduced.
Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: acme@kernel.org Cc: eranian@google.com Link: http://lkml.kernel.org/r/1525371913-10597-2-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- arch/x86/kernel/cpu/perf_event_intel_uncore_nhmex.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore_nhmex.c +++ b/arch/x86/kernel/cpu/perf_event_intel_uncore_nhmex.c @@ -240,7 +240,7 @@ static void nhmex_uncore_msr_enable_even { struct hw_perf_event *hwc = &event->hw; - if (hwc->idx >= UNCORE_PMC_IDX_FIXED) + if (hwc->idx == UNCORE_PMC_IDX_FIXED) wrmsrl(hwc->config_base, NHMEX_PMON_CTL_EN_BIT0); else if (box->pmu->type->event_mask & NHMEX_PMON_CTL_EN_BIT0) wrmsrl(hwc->config_base, hwc->config | NHMEX_PMON_CTL_EN_BIT22);
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