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| author | Jens Axboe <axboe@kernel.dk> | 2021-10-05 09:23:59 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-10-18 06:17:03 -0600 |
| commit | 0006707723233cb2a9a23ca19fc3d0864835704c (patch) | |
| tree | 6bbd7e9c8b99456d8d993b38aacbc2e07129e6dd /block/blk-core.c | |
| parent | a7b36ee6ba299ffa5c3b36af187b4d0fb32a557c (diff) | |
block: inherit request start time from bio for BLK_CGROUP
Doing high IOPS testing with blk-cgroups enabled spends ~15-20% of the
time just doing ktime_get_ns() -> readtsc. We essentially read and
set the start time twice, one for the bio and then again when that bio
is mapped to a request.
Given that the time between the two is very short, inherit the bio
start time instead of reading it again. This cuts 1/3rd of the overhead
of the time keeping.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-core.c')
0 files changed, 0 insertions, 0 deletions