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| author | Jens Axboe <axboe@kernel.dk> | 2018-12-04 09:45:32 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-12-18 08:29:58 -0700 |
| commit | a79d40e9b0f309dcddc4e0bf5b64e51e28153e55 (patch) | |
| tree | f7974ad993b0b69c6702c2330cc0df37ade170df | |
| parent | 2bc4ca9bb600cbe36941da2b2a67189fc4302a04 (diff) | |
| download | blackbird-op-linux-a79d40e9b0f309dcddc4e0bf5b64e51e28153e55.tar.gz blackbird-op-linux-a79d40e9b0f309dcddc4e0bf5b64e51e28153e55.zip | |
aio: only use blk plugs for > 2 depth submissions
Plugging is meant to optimize submission of a string of IOs, if we don't
have more than 2 being submitted, don't bother setting up a plug.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | fs/aio.c | 18 |
1 files changed, 14 insertions, 4 deletions
@@ -70,6 +70,12 @@ struct aio_ring { struct io_event io_events[0]; }; /* 128 bytes + ring size */ +/* + * Plugging is meant to work with larger batches of IOs. If we don't + * have more than the below, then don't bother setting up a plug. + */ +#define AIO_PLUG_THRESHOLD 2 + #define AIO_RING_PAGES 8 struct kioctx_table { @@ -1921,7 +1927,8 @@ SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr, if (nr > ctx->nr_events) nr = ctx->nr_events; - blk_start_plug(&plug); + if (nr > AIO_PLUG_THRESHOLD) + blk_start_plug(&plug); for (i = 0; i < nr; i++) { struct iocb __user *user_iocb; @@ -1934,7 +1941,8 @@ SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr, if (ret) break; } - blk_finish_plug(&plug); + if (nr > AIO_PLUG_THRESHOLD) + blk_finish_plug(&plug); percpu_ref_put(&ctx->users); return i ? i : ret; @@ -1961,7 +1969,8 @@ COMPAT_SYSCALL_DEFINE3(io_submit, compat_aio_context_t, ctx_id, if (nr > ctx->nr_events) nr = ctx->nr_events; - blk_start_plug(&plug); + if (nr > AIO_PLUG_THRESHOLD) + blk_start_plug(&plug); for (i = 0; i < nr; i++) { compat_uptr_t user_iocb; @@ -1974,7 +1983,8 @@ COMPAT_SYSCALL_DEFINE3(io_submit, compat_aio_context_t, ctx_id, if (ret) break; } - blk_finish_plug(&plug); + if (nr > AIO_PLUG_THRESHOLD) + blk_finish_plug(&plug); percpu_ref_put(&ctx->users); return i ? i : ret; |
