perf: Add pmu specific data for perf task context

Introduce a new flag PERF_ATTACH_TASK_DATA for perf event's attach
stata. The flag is set by PMU's event_init() callback, it indicates
that perf event needs PMU specific data.

The PMU specific data are initialized to zeros. Later patches will
use PMU specific data to save LBR stack.

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/1415156173-10035-6-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index c7007a564440..270cd0173e61 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -271,6 +271,10 @@ struct pmu {
          */
         void (*sched_task)              (struct perf_event_context *ctx,
                                         bool sched_in);
+        /*
+         * PMU specific data size
+         */
+        size_t                          task_ctx_size;
 
 };
 
@@ -307,6 +311,7 @@ struct swevent_hlist {
 #define PERF_ATTACH_CONTEXT     0x01
 #define PERF_ATTACH_GROUP       0x02
 #define PERF_ATTACH_TASK        0x04
+#define PERF_ATTACH_TASK_DATA   0x08
 
 struct perf_cgroup;
 struct ring_buffer;
@@ -511,6 +516,7 @@ struct perf_event_context {
         u64                             generation;
         int                             pin_count;
         int                             nr_cgroups;      /* cgroup evts */
+        void                            *task_ctx_data; /* pmu specific data */
         struct rcu_head                 rcu_head;
 
         struct delayed_work             orphans_remove;