perf: Extend the mmap control page with time (TSC) fields

Extend the mmap control page with fields so that userspace can compute
time deltas relative to the provided time fields.

Currently only implemented for x86 with constant and nonstop TSC.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Arun Sharma <asharma@fb.com>
Link: http://lkml.kernel.org/n/tip-3u1jucza77j3wuvs0x2bic0f@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 3 insertions, 1 deletions

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 5311b79fe62c..0b91db2522cc 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -291,12 +291,14 @@ struct perf_event_mmap_page {
         __s64   offset;                 /* add to hardware event value */
         __u64   time_enabled;           /* time event active */
         __u64   time_running;           /* time event on cpu */
+        __u32   time_mult, time_shift;
+        __u64   time_offset;
 
                 /*
                  * Hole for extension of the self monitor capabilities
                  */
 
-        __u64   __reserved[123];        /* align to 1k */
+        __u64   __reserved[121];        /* align to 1k */
 
         /*
          * Control data for the mmap() data buffer.