[ Upstream commit 871a93b0aad65a7f44ee25f2d17932ef6d559850 ]
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: 5738891229a2 ("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.... Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/events/core.c | 6 +++++- arch/x86/events/perf_event.h | 1 + 2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index 4103665c6e032..29640b4079af0 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -1087,8 +1087,10 @@ static int collect_events(struct cpu_hw_events *cpuc, struct perf_event *leader,
cpuc->event_list[n] = event; n++; - if (is_counter_pair(&event->hw)) + if (is_counter_pair(&event->hw)) { cpuc->n_pair++; + cpuc->n_txn_pair++; + } } return n; } @@ -1953,6 +1955,7 @@ 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); }
/* @@ -1978,6 +1981,7 @@ 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); }
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h index e17a3d8a47ede..d4d482d16fe18 100644 --- a/arch/x86/events/perf_event.h +++ b/arch/x86/events/perf_event.h @@ -198,6 +198,7 @@ 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];