Commits
Jens Axboe committed 54a91f3bb9b
io_uring: limit parallelism of buffered writes All the popular filesystems need to grab the inode lock for buffered writes. With io_uring punting buffered writes to async context, we observe a lot of contention with all workers hamming this mutex. For buffered writes, we generally don't need a lot of parallelism on the submission side, as the flushing will take care of that for us. Hence we don't need a deep queue on the write side, as long as we can safely punt from the original submission context. Add a workqueue with a limit of 2 that we can use for buffered writes. This greatly improves the performance and efficiency of higher queue depth buffered async writes with io_uring. Reported-by: Andres Freund <andres@anarazel.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>