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| author | Dmitry Monakhov <dmonakhov@gmail.com> | 2019-11-01 13:11:10 +0000 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-11-20 16:10:29 -0700 |
| commit | 40d47c155e8ae9bcb3f2d0d01cf14d903c664726 (patch) | |
| tree | 80e724192c2ecdb7b0f7199ecadc452fa17d48c8 /Documentation/ABI/testing/sysfs-block | |
| parent | c6da429ea988de8f9330405fc405ee32479b5bd5 (diff) | |
| download | linux-next-40d47c155e8ae9bcb3f2d0d01cf14d903c664726.tar.gz | |
block,bfq: Skip tracing hooks if possible
In most cases blk_tracing is not active, but bfq_log_bfqq macro
generate pid_str unconditionally, which result in significant overhead.
## Test
modprobe null_blk
echo bfq > /sys/block/nullb0/queue/scheduler
fio --name=t --ioengine=libaio --direct=1 --filename=/dev/nullb0 \
--runtime=30 --time_based=1 --rw=write --iodepth=128 --bs=4k
# Results
| | baseline | w/ patch | gain |
| iops | 113.19K | 126.42K | +11% |
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Dmitry Monakhov <dmonakhov@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'Documentation/ABI/testing/sysfs-block')
0 files changed, 0 insertions, 0 deletions