[PATCH] block: small performance optimization

[Matias BjÃrling]

Hi Jens,

The IO accounting stats contribute significant overhead on high IO/multi-node
workloads. By moving the in_flight IO tracking to per-cpu counters, we can
elevate some of the cache coherence overhead, at the cost of setup/teardown
and percpu counters structure within the hd_struct structure.

Sam Bradshaw reported an IOPS increase of 20% on his fio workloads.

Thanks,
Matias

Matias BjÃrling (1):
  blk: per-cpu counters for in-flight IO accounting

 block/partition-generic.c |  4 ++--
 include/linux/genhd.h     | 25 ++++++++++++++++++-------
 2 files changed, 20 insertions(+), 9 deletions(-)

-- 
1.9.1

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