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Subject[PATCH V7 01/14] perf/x86: Use event_base_rdpmc for the RDPMC userspace support
Date
From: Kan Liang <kan.liang@linux.intel.com>

The RDPMC index is always re-calculated for the RDPMC userspace support,
which is unnecessary.

The RDPMC index value is stored in the variable event_base_rdpmc for
the kernel usage, which can be used for RDPMC userspace support as well.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
---
arch/x86/events/core.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 1cbf57dc2ac8..8e108ea378e3 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2208,17 +2208,12 @@ static void x86_pmu_event_unmapped(struct perf_event *event, struct mm_struct *m

static int x86_pmu_event_idx(struct perf_event *event)
{
- int idx = event->hw.idx;
+ struct hw_perf_event *hwc = &event->hw;

- if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED))
+ if (!(hwc->flags & PERF_X86_EVENT_RDPMC_ALLOWED))
return 0;

- if (x86_pmu.num_counters_fixed && idx >= INTEL_PMC_IDX_FIXED) {
- idx -= INTEL_PMC_IDX_FIXED;
- idx |= 1 << 30;
- }
-
- return idx + 1;
+ return hwc->event_base_rdpmc + 1;
}

static ssize_t get_attr_rdpmc(struct device *cdev,
--
2.17.1
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