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authorYan, Zheng <zheng.z.yan@intel.com>2014-11-05 02:56:02 (GMT)
committerIngo Molnar <mingo@kernel.org>2015-02-18 16:16:07 (GMT)
commit5a158c3ccd2183a7b0866be6685d001fe653430f (patch)
treeb270d5bca5169d27285abead59f8cbf74dda683a
parent4af57ef28c2c1047fda9e1a5be02aa7a6a69cf9e (diff)
downloadlinux-5a158c3ccd2183a7b0866be6685d001fe653430f.tar.xz
perf: Always switch pmu specific data during context switch
If two tasks were both forked from the same parent task, Events in their perf task contexts can be the same. Perf core may leave out switching the perf event contexts. Previous patch inroduces pmu specific data. The data is for saving the LBR stack, it is task specific. So we need to switch the data even when context switch is optimized out. Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: eranian@google.com Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/1415156173-10035-7-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--kernel/events/core.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 688086b..84451c0 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2562,6 +2562,9 @@ static void perf_event_context_sched_out(struct task_struct *task, int ctxn,
next->perf_event_ctxp[ctxn] = ctx;
ctx->task = next;
next_ctx->task = task;
+
+ swap(ctx->task_ctx_data, next_ctx->task_ctx_data);
+
do_switch = 0;
perf_event_sync_stat(ctx, next_ctx);