On Fri 29-04-16 12:27:56, Waiman Long wrote:

This patch changes the es_stats_cache_hits and es_stats_cache_misses
statistics counts to percpu counters to reduce cacheline contention
issues whem multiple threads are trying to update those counts
simultaneously.

With a 38-threads fio I/O test with 2 shared files (on DAX-mount
NVDIMM) running on a 4-socket Haswell-EX server with 4.6-rc1 kernel,
the aggregated bandwidths before and after the patch were:

  Test          W/O patch       With patch      % change
  ----          ---------       ----------      --------
  Read-only     16499MB/s       17215MB/s        +4.3%
  Read-write     4361MB/s        4794MB/s        +9.9%

Signed-off-by: Waiman Long <redacted>

The patch looks good. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

-- 
Jan Kara [off-list ref]
SUSE Labs, CR