Commit-ID: 827db839cd051cfde5a618fb4427e86dc91bc9aa
Gitweb: http://git.kernel.org/tip/827db839cd051cfde5a618fb4427e86dc91bc9aa
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Mon, 22 Feb 2016 22:19:20 +0000
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Mon, 29 Feb 2016 09:35:21 +0100
perf/x86/intel/cqm: Get rid of the silly for_each_cpu() lookups
CQM is a strict per package facility. Use the proper cpumasks to lookup the
readers.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Andi Kleen <andi.kleen@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Harish Chegondi <harish.chegondi@xxxxxxxxx>
Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Vince Weaver <vincent.weaver@xxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20160222221012.054916179@xxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/events/intel/cqm.c | 32 +++++++++++---------------------
1 file changed, 11 insertions(+), 21 deletions(-)
diff --git a/arch/x86/events/intel/cqm.c b/arch/x86/events/intel/cqm.c
index 1b064c4..93cb412 100644
--- a/arch/x86/events/intel/cqm.c
+++ b/arch/x86/events/intel/cqm.c
@@ -1244,15 +1244,12 @@ static struct pmu intel_cqm_pmu = {
static inline void cqm_pick_event_reader(int cpu)
{
- int phys_id = topology_physical_package_id(cpu);
- int i;
+ int reader;
- for_each_cpu(i, &cqm_cpumask) {
- if (phys_id == topology_physical_package_id(i))
- return; /* already got reader for this socket */
- }
-
- cpumask_set_cpu(cpu, &cqm_cpumask);
+ /* First online cpu in package becomes the reader */
+ reader = cpumask_any_and(&cqm_cpumask, topology_core_cpumask(cpu));
+ if (reader >= nr_cpu_ids)
+ cpumask_set_cpu(cpu, &cqm_cpumask);
}
static void intel_cqm_cpu_starting(unsigned int cpu)
@@ -1270,24 +1267,17 @@ static void intel_cqm_cpu_starting(unsigned int cpu)
static void intel_cqm_cpu_exit(unsigned int cpu)
{
- int phys_id = topology_physical_package_id(cpu);
- int i;
+ int target;
- /*
- * Is @cpu a designated cqm reader?
- */
+ /* Is @cpu the current cqm reader for this package ? */
if (!cpumask_test_and_clear_cpu(cpu, &cqm_cpumask))
return;
- for_each_online_cpu(i) {
- if (i == cpu)
- continue;
+ /* Find another online reader in this package */
+ target = cpumask_any_but(topology_core_cpumask(cpu), cpu);
- if (phys_id == topology_physical_package_id(i)) {
- cpumask_set_cpu(i, &cqm_cpumask);
- break;
- }
- }
+ if (target < nr_cpu_ids)
+ cpumask_set_cpu(target, &cqm_cpumask);
}
static int intel_cqm_cpu_notifier(struct notifier_block *nb,
--
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