From: Kan Liang kan.liang@linux.intel.com
mainline inclusion from mainline-v5.10-rc1 commit 75608cb02ea5dd997990e2998eca3670cb71a18c category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I47H3V CVE: NA
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commit 75608cb02ea5dd997990e2998eca3670cb71a18c upstream Backport summary: backport to kernel 4.19.57 for ICX perf topdown support
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 Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Link: https://lkml.kernel.org/r/20200723171117.9918-2-kan.liang@linux.intel.com Signed-off-by: Yunying Sun yunying.sun@intel.com Signed-off-by: Jackie Liu liuyun01@kylinos.cn Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Reviewed-by: Wei Li liwei391@huawei.com Reviewed-by: Xie XiuQi xiexiuqi@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.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 b4b3ecc9bbba..60bca5389ed5 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -2149,17 +2149,12 @@ 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,