perf/x86: Fix n_pair for cancelled txn (871a93b0) · Commits · 戴 / test

Kan reported that n_metric gets corrupted for cancelled transactions; a similar issue exists for n_pair for AMD's Large Increment thing. The problem was confirmed and confirmed fixed by Kim using: sudo perf stat -e "{cycles,cycles,cycles,cycles}:D" -a sleep 10 & # should succeed: sudo perf stat -e "{fp_ret_sse_avx_ops.all}:D" -a workload # should fail: sudo perf stat -e "{fp_ret_sse_avx_ops.all,fp_ret_sse_avx_ops.all,cycles}:D" -a workload # previously failed, now succeeds with this patch: sudo perf stat -e "{fp_ret_sse_avx_ops.all}:D" -a workload Fixes: ("perf/x86/amd: Add support for Large Increment per Cycle Events") Reported-by:

Kan Liang <kan.liang@linux.intel.com> Signed-off-by:

Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by:

Kim Phillips <kim.phillips@amd.com> Link: https://lkml.kernel.org/r/20201005082516.GG2628@hirez.programming.kicks-ass.net

arch/x86/events/core.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -1064,8 +1064,10 @@ static int collect_event(struct cpu_hw_events cpuc, struct perf_event event,
		return -EINVAL;

		cpuc->event_list[n] = event;
		if (is_counter_pair(&event->hw))
		if (is_counter_pair(&event->hw)) {
		cpuc->n_pair++;
		cpuc->n_txn_pair++;
		}

		return 0;
		}
		@@ -2006,6 +2008,7 @@ static void x86_pmu_start_txn(struct pmu *pmu, unsigned int txn_flags)

		perf_pmu_disable(pmu);
		__this_cpu_write(cpu_hw_events.n_txn, 0);
		__this_cpu_write(cpu_hw_events.n_txn_pair, 0);
		}

		/*
		@@ -2031,6 +2034,7 @@ static void x86_pmu_cancel_txn(struct pmu *pmu)
		*/
		__this_cpu_sub(cpu_hw_events.n_added, __this_cpu_read(cpu_hw_events.n_txn));
		__this_cpu_sub(cpu_hw_events.n_events, __this_cpu_read(cpu_hw_events.n_txn));
		__this_cpu_sub(cpu_hw_events.n_pair, __this_cpu_read(cpu_hw_events.n_txn_pair));
		perf_pmu_enable(pmu);
		}

arch/x86/events/perf_event.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -235,6 +235,7 @@ struct cpu_hw_events {
		they've never been enabled yet */
		int n_txn; /* the # last events in the below arrays;
		added in the current transaction */
		int n_txn_pair;
		int assign[X86_PMC_IDX_MAX]; /* event to counter assignment */
		u64 tags[X86_PMC_IDX_MAX];

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