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authorZhou Chengming <zhouchengming1@huawei.com>2017-01-16 11:21:11 +0800
committerThomas Gleixner <tglx@linutronix.de>2017-01-17 11:08:36 +0100
commit4e71de7986386d5fd3765458f27d612931f27f5e (patch)
treeb5ca21b15c61a7645057a489271c0daf546e90a1 /arch
parent49def1853334396f948dcb4cedb9347abb318df5 (diff)
downloadlinux-4e71de7986386d5fd3765458f27d612931f27f5e.tar.bz2
perf/x86/intel: Handle exclusive threadid correctly on CPU hotplug
The CPU hotplug function intel_pmu_cpu_starting() sets cpu_hw_events.excl_thread_id unconditionally to 1 when the shared exclusive counters data structure is already availabe for the sibling thread. This works during the boot process because the first sibling gets threadid 0 assigned and the second sibling which shares the data structure gets 1. But when the first thread of the core is offlined and onlined again it shares the data structure with the second thread and gets exclusive thread id 1 assigned as well. Prevent this by checking the threadid of the already online thread. [ tglx: Rewrote changelog ] Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com> Cc: NuoHan Qiao <qiaonuohan@huawei.com> Cc: ak@linux.intel.com Cc: peterz@infradead.org Cc: kan.liang@intel.com Cc: dave.hansen@linux.intel.com Cc: eranian@google.com Cc: qiaonuohan@huawei.com Cc: davidcc@google.com Cc: guohanjun@huawei.com Link: http://lkml.kernel.org/r/1484536871-3131-1-git-send-email-zhouchengming1@huawei.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- --- arch/x86/events/intel/core.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/events/intel/core.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index d611cab214a6..eb1484c86bb4 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3176,13 +3176,16 @@ static void intel_pmu_cpu_starting(int cpu)
if (x86_pmu.flags & PMU_FL_EXCL_CNTRS) {
for_each_cpu(i, topology_sibling_cpumask(cpu)) {
+ struct cpu_hw_events *sibling;
struct intel_excl_cntrs *c;
- c = per_cpu(cpu_hw_events, i).excl_cntrs;
+ sibling = &per_cpu(cpu_hw_events, i);
+ c = sibling->excl_cntrs;
if (c && c->core_id == core_id) {
cpuc->kfree_on_online[1] = cpuc->excl_cntrs;
cpuc->excl_cntrs = c;
- cpuc->excl_thread_id = 1;
+ if (!sibling->excl_thread_id)
+ cpuc->excl_thread_id = 1;
break;
}
}