Hi,
Can you add the below to 6.1-stable? Thanks!
commit 3181e22fb79910c7071e84a43af93ac89e8a7106
Author: Pavel Begunkov <asml.silence@xxxxxxxxx>
Date: Mon Jan 9 14:46:10 2023 +0000
io_uring: wake up optimisations
Commit 3181e22fb79910c7071e84a43af93ac89e8a7106 upstream.
Flush completions is done either from the submit syscall or by the
task_work, both are in the context of the submitter task, and when it
goes for a single threaded rings like implied by ->task_complete, there
won't be any waiters on ->cq_wait but the master task. That means that
there can be no tasks sleeping on cq_wait while we run
__io_submit_flush_completions() and so waking up can be skipped.
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Link: https://lore.kernel.org/r/60ad9768ec74435a0ddaa6eec0ffa7729474f69f.1673274244.git.asml.silence@xxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 4f0ae938b146..0b1361663267 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -582,6 +582,16 @@ static inline void __io_cq_unlock_post(struct io_ring_ctx *ctx)
io_cqring_ev_posted(ctx);
}
+static inline void __io_cq_unlock_post_flush(struct io_ring_ctx *ctx)
+ __releases(ctx->completion_lock)
+{
+ io_commit_cqring(ctx);
+ spin_unlock(&ctx->completion_lock);
+ io_commit_cqring_flush(ctx);
+ if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN))
+ __io_cqring_wake(ctx);
+}
+
void io_cq_unlock_post(struct io_ring_ctx *ctx)
{
__io_cq_unlock_post(ctx);
@@ -1339,7 +1349,7 @@ static void __io_submit_flush_completions(struct io_ring_ctx *ctx)
if (!(req->flags & REQ_F_CQE_SKIP))
__io_fill_cqe_req(ctx, req);
}
- __io_cq_unlock_post(ctx);
+ __io_cq_unlock_post_flush(ctx);
io_free_batch_list(ctx, state->compl_reqs.first);
INIT_WQ_LIST(&state->compl_reqs);
--
Jens Axboe
