Commit-ID: 109717de57b95d6dd9582c18a74f154d69fea536
Gitweb: https://git.kernel.org/tip/109717de57b95d6dd9582c18a74f154d69fea536
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Thu, 14 Mar 2019 13:17:51 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 3 Apr 2019 09:25:33 +0200
perf/x86: Optimize x86_schedule_events()
Now that cpuc->event_constraint[] is retained, we can avoid calling
get_event_constraints() over and over again.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vince Weaver <vincent.weaver@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/events/core.c | 13 +++++++++++--
arch/x86/events/intel/core.c | 3 ++-
2 files changed, 13 insertions(+), 3 deletions(-)
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 279530111d8e..fa88acf0daad 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -858,8 +858,17 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
x86_pmu.start_scheduling(cpuc);
for (i = 0, wmin = X86_PMC_IDX_MAX, wmax = 0; i < n; i++) {
- c = x86_pmu.get_event_constraints(cpuc, i, cpuc->event_list[i]);
- cpuc->event_constraint[i] = c;
+ c = cpuc->event_constraint[i];
+
+ /*
+ * Request constraints for new events; or for those events that
+ * have a dynamic constraint -- for those the constraint can
+ * change due to external factors (sibling state, allow_tfa).
+ */
+ if (!c || (c->flags & PERF_X86_EVENT_DYNAMIC)) {
+ c = x86_pmu.get_event_constraints(cpuc, i, cpuc->event_list[i]);
+ cpuc->event_constraint[i] = c;
+ }
wmin = min(wmin, c->weight);
wmax = max(wmax, c->weight);
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index a80015fa8aed..62394e1b2390 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -2945,7 +2945,8 @@ intel_get_event_constraints(struct cpu_hw_events *cpuc, int idx,
* - dynamic constraint: handled by intel_get_excl_constraints()
*/
c2 = __intel_get_event_constraints(cpuc, idx, event);
- if (c1 && (c1->flags & PERF_X86_EVENT_DYNAMIC)) {
+ if (c1) {
+ WARN_ON_ONCE(!(c1->flags & PERF_X86_EVENT_DYNAMIC));
bitmap_copy(c1->idxmsk, c2->idxmsk, X86_PMC_IDX_MAX);
c1->weight = c2->weight;
c2 = c1;
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