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| author | Ming Lei <ming.lei@redhat.com> | 2025-06-25 05:25:54 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2025-06-25 05:44:52 +0300 |
| commit | 524346e9d79f63a6e5aaa645140da3d1ec7a8a0f (patch) | |
| tree | 7100642594e9cb268a5660312aff30874b31695a | |
| parent | 8c8472855884355caf3d8e0c50adf825f83454b2 (diff) | |
| download | linux-524346e9d79f63a6e5aaa645140da3d1ec7a8a0f.tar.xz | |
ublk: build batch from IOs in same io_ring_ctx and io task
ublk_queue_cmd_list() dispatches the whole batch list by scheduling task
work via the tail request's io_uring_cmd, this way is fine even though
more than one io_ring_ctx are involved for this batch since it is just
one running context.
However, the task work handler ublk_cmd_list_tw_cb() takes `issue_flags`
of tail uring_cmd's io_ring_ctx for completing all commands. This way is
wrong if any uring_cmd is issued from different io_ring_ctx.
Fixes it by always building batch IOs from same io_ring_ctx and io task
because ublk_dispatch_req() does validate task context, and IO needs to
be aborted in case of running from fallback task work context.
For typical per-queue or per-io daemon implementation, this way shouldn't
make difference from performance viewpoint, because single io_ring_ctx is
taken in each daemon for normal use case.
Fixes: d796cea7b9f3 ("ublk: implement ->queue_rqs()")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250625022554.883571-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | drivers/block/ublk_drv.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index d36f44f5ee80..90c02ced392a 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -1416,6 +1416,14 @@ static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx, return BLK_STS_OK; } +static inline bool ublk_belong_to_same_batch(const struct ublk_io *io, + const struct ublk_io *io2) +{ + return (io_uring_cmd_ctx_handle(io->cmd) == + io_uring_cmd_ctx_handle(io2->cmd)) && + (io->task == io2->task); +} + static void ublk_queue_rqs(struct rq_list *rqlist) { struct rq_list requeue_list = { }; @@ -1427,7 +1435,8 @@ static void ublk_queue_rqs(struct rq_list *rqlist) struct ublk_queue *this_q = req->mq_hctx->driver_data; struct ublk_io *this_io = &this_q->ios[req->tag]; - if (io && io->task != this_io->task && !rq_list_empty(&submit_list)) + if (io && !ublk_belong_to_same_batch(io, this_io) && + !rq_list_empty(&submit_list)) ublk_queue_cmd_list(io, &submit_list); io = this_io; |