From: Kan Liang kan.liang@linux.intel.com
[ Upstream commit 75be6f703a141b048590d659a3954c4fedd30bba ]
The events in the same group don't start or stop simultaneously. Here is the ftrace when enabling event group for uncore_iio_0:
# perf stat -e "{uncore_iio_0/event=0x1/,uncore_iio_0/event=0xe/}"
<idle>-0 [000] d.h. 8959.064832: read_msr: a41, value b2b0b030 //Read counter reg of IIO unit0 counter0 <idle>-0 [000] d.h. 8959.064835: write_msr: a48, value 400001 //Write Ctrl reg of IIO unit0 counter0 to enable counter0. <------ Although counter0 is enabled, Unit Ctrl is still freezed. Nothing will count. We are still good here. <idle>-0 [000] d.h. 8959.064836: read_msr: a40, value 30100 //Read Unit Ctrl reg of IIO unit0 <idle>-0 [000] d.h. 8959.064838: write_msr: a40, value 30000 //Write Unit Ctrl reg of IIO unit0 to enable all counters in the unit by clear Freeze bit <------Unit0 is un-freezed. Counter0 has been enabled. Now it starts counting. But counter1 has not been enabled yet. The issue starts here. <idle>-0 [000] d.h. 8959.064846: read_msr: a42, value 0 //Read counter reg of IIO unit0 counter1 <idle>-0 [000] d.h. 8959.064847: write_msr: a49, value 40000e //Write Ctrl reg of IIO unit0 counter1 to enable counter1. <------ Now, counter1 just starts to count. Counter0 has been running for a while.
Current code un-freezes the Unit Ctrl right after the first counter is enabled. The subsequent group events always loses some counter values.
Implement pmu_enable and pmu_disable support for uncore, which can help to batch hardware accesses.
No one uses uncore_enable_box and uncore_disable_box. Remove them.
Signed-off-by: Kan Liang kan.liang@linux.intel.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Arnaldo Carvalho de Melo acme@redhat.com Cc: Jiri Olsa jolsa@redhat.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Mark Rutland mark.rutland@arm.com Cc: Namhyung Kim namhyung@kernel.org Cc: Stephane Eranian eranian@google.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Vince Weaver vincent.weaver@maine.edu Cc: linux-drivers-review@eclists.intel.com Cc: linux-perf@eclists.intel.com Fixes: 087bfbb03269 ("perf/x86: Add generic Intel uncore PMU support") Link: https://lkml.kernel.org/r/1572014593-31591-1-git-send-email-kan.liang@linux.... Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/events/intel/uncore.c | 44 +++++++++++++++++++++++++++++----- arch/x86/events/intel/uncore.h | 12 ---------- 2 files changed, 38 insertions(+), 18 deletions(-)
diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c index 3694a5d0703d9..f7b191d3c9b01 100644 --- a/arch/x86/events/intel/uncore.c +++ b/arch/x86/events/intel/uncore.c @@ -502,10 +502,8 @@ void uncore_pmu_event_start(struct perf_event *event, int flags) local64_set(&event->hw.prev_count, uncore_read_counter(box, event)); uncore_enable_event(box, event);
- if (box->n_active == 1) { - uncore_enable_box(box); + if (box->n_active == 1) uncore_pmu_start_hrtimer(box); - } }
void uncore_pmu_event_stop(struct perf_event *event, int flags) @@ -529,10 +527,8 @@ void uncore_pmu_event_stop(struct perf_event *event, int flags) WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED); hwc->state |= PERF_HES_STOPPED;
- if (box->n_active == 0) { - uncore_disable_box(box); + if (box->n_active == 0) uncore_pmu_cancel_hrtimer(box); - } }
if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) { @@ -778,6 +774,40 @@ static int uncore_pmu_event_init(struct perf_event *event) return ret; }
+static void uncore_pmu_enable(struct pmu *pmu) +{ + struct intel_uncore_pmu *uncore_pmu; + struct intel_uncore_box *box; + + uncore_pmu = container_of(pmu, struct intel_uncore_pmu, pmu); + if (!uncore_pmu) + return; + + box = uncore_pmu_to_box(uncore_pmu, smp_processor_id()); + if (!box) + return; + + if (uncore_pmu->type->ops->enable_box) + uncore_pmu->type->ops->enable_box(box); +} + +static void uncore_pmu_disable(struct pmu *pmu) +{ + struct intel_uncore_pmu *uncore_pmu; + struct intel_uncore_box *box; + + uncore_pmu = container_of(pmu, struct intel_uncore_pmu, pmu); + if (!uncore_pmu) + return; + + box = uncore_pmu_to_box(uncore_pmu, smp_processor_id()); + if (!box) + return; + + if (uncore_pmu->type->ops->disable_box) + uncore_pmu->type->ops->disable_box(box); +} + static ssize_t uncore_get_attr_cpumask(struct device *dev, struct device_attribute *attr, char *buf) { @@ -803,6 +833,8 @@ static int uncore_pmu_register(struct intel_uncore_pmu *pmu) pmu->pmu = (struct pmu) { .attr_groups = pmu->type->attr_groups, .task_ctx_nr = perf_invalid_context, + .pmu_enable = uncore_pmu_enable, + .pmu_disable = uncore_pmu_disable, .event_init = uncore_pmu_event_init, .add = uncore_pmu_event_add, .del = uncore_pmu_event_del, diff --git a/arch/x86/events/intel/uncore.h b/arch/x86/events/intel/uncore.h index f36f7bebbc1bb..bbfdaa720b456 100644 --- a/arch/x86/events/intel/uncore.h +++ b/arch/x86/events/intel/uncore.h @@ -441,18 +441,6 @@ static inline int uncore_freerunning_hw_config(struct intel_uncore_box *box, return -EINVAL; }
-static inline void uncore_disable_box(struct intel_uncore_box *box) -{ - if (box->pmu->type->ops->disable_box) - box->pmu->type->ops->disable_box(box); -} - -static inline void uncore_enable_box(struct intel_uncore_box *box) -{ - if (box->pmu->type->ops->enable_box) - box->pmu->type->ops->enable_box(box); -} - static inline void uncore_disable_event(struct intel_uncore_box *box, struct perf_event *event) {