On Wed, Feb 10, 2016 at 05:38:02PM -0500, Tong Zhang wrote: > commit a7b58d211ba18c9175b139e18b68c86a6bcc3c3f introduced feature of > timestamp on free running PEBSv3, however, the timestamp is later > overwritten, which makes the effort in vain. > > This patch fixed this problem by detecting whether timestamp is provided. > > Signed-off-by: Tong Zhang <[email protected]> > --- > include/linux/perf_event.h | 1 + > kernel/events/core.c | 45 > +++++++++++++++++++++++++++++++++------------ > kernel/events/ring_buffer.c | 4 +++- > 3 files changed, 37 insertions(+), 13 deletions(-) > > diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h > index f9828a4..12d7b95 100644 > --- a/include/linux/perf_event.h > +++ b/include/linux/perf_event.h > @@ -815,6 +815,7 @@ static inline void perf_sample_data_init(struct > perf_sample_data *data, > data->weight = 0; > data->data_src.val = PERF_MEM_NA; > data->txn = 0; > + data->time = 0; > }
Argh, you just touched a new cacheline and made _every_ single event slower.
