[PATCH] block: small performance optimization

Matias Bjørling
2014-05-09T09:18:32Z

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 Bjørling (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(-)

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1.9.1