perf_counter: track task-comm data

Similar to the mmap data stream, add one that tracks the task COMM field,
so that the userspace reporting knows what to call a task.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090408130409.127422406@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 15 insertions, 1 deletions

diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index 8bf764fc6220..a70a55f27598 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -142,8 +142,9 @@ struct perf_counter_hw_event {
                                 exclude_idle   :  1, /* don't count when idle */
                                 mmap           :  1, /* include mmap data     */
                                 munmap         :  1, /* include munmap data   */
+                                comm           :  1, /* include comm data     */
 
-                                __reserved_1   : 53;
+                                __reserved_1   : 52;
 
         __u32                   extra_config_len;
         __u32                   wakeup_events;  /* wakeup every n events */
@@ -231,6 +232,16 @@ enum perf_event_type {
         PERF_EVENT_MUNMAP               = 2,
 
         /*
+         * struct {
+         *      struct perf_event_header        header;
+         *
+         *      u32                             pid, tid;
+         *      char                            comm[];
+         * };
+         */
+        PERF_EVENT_COMM                 = 3,
+
+        /*
          * When header.misc & PERF_EVENT_MISC_OVERFLOW the event_type field
          * will be PERF_RECORD_*
          *
@@ -545,6 +556,8 @@ extern void perf_counter_mmap(unsigned long addr, unsigned long len,
 extern void perf_counter_munmap(unsigned long addr, unsigned long len,
                                 unsigned long pgoff, struct file *file);
 
+extern void perf_counter_comm(struct task_struct *tsk);
+
 #define MAX_STACK_DEPTH         255
 
 struct perf_callchain_entry {
@@ -583,6 +596,7 @@ static inline void
 perf_counter_munmap(unsigned long addr, unsigned long len,
                     unsigned long pgoff, struct file *file)             { }
 
+static inline void perf_counter_comm(struct task_struct *tsk)           { }
 #endif
 
 #endif /* __KERNEL__ */