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authorYan, Zheng2014-11-05 03:56:02 +0100
committerIngo Molnar2015-02-18 17:16:07 +0100
commit5a158c3ccd2183a7b0866be6685d001fe653430f (patch)
treeb270d5bca5169d27285abead59f8cbf74dda683a /kernel/events/core.c
parentperf: Add pmu specific data for perf task context (diff)
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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>
Diffstat (limited to 'kernel/events/core.c')
-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 688086bb7144..84451c0debba 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);