tree 6949a688812bbf7a87aaea690873598364e4eb2a
parent bdcd3eab2a9ae0ac93f27275b6895dd95e5bf360
author Jens Axboe <axboe@kernel.dk> 1582645650 -0700
committer Jens Axboe <axboe@kernel.dk> 1582646257 -0700

io-wq: remove spin-for-work optimization

Andres reports that buffered IO seems to suck up more cycles than we
would like, and he narrowed it down to the fact that the io-wq workers
will briefly spin for more work on completion of a work item. This was
a win on the networking side, but apparently some other cases take a
hit because of it. Remove the optimization to avoid burning more CPU
than we have to for disk IO.

Reported-by: Andres Freund <andres@anarazel.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>