From: Pavel Begunkov <[email protected]> Any changes interesting to tasks waiting in io_cqring_wait() are commited with io_cqring_ev_posted(). However, io_ring_drop_ctx_refs() also tries to do that but with no reason, that means spurious wakeups every io_free_req() and io_uring_enter().
Just use percpu_ref_put() instead. Signed-off-by: Pavel Begunkov <[email protected]> --- fs/io_uring.c | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index c934f91c51e9..89d77a626063 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -591,14 +591,6 @@ static void io_cqring_add_event(struct io_ring_ctx *ctx, u64 user_data, io_cqring_ev_posted(ctx); } -static void io_ring_drop_ctx_refs(struct io_ring_ctx *ctx, unsigned refs) -{ - percpu_ref_put_many(&ctx->refs, refs); - - if (waitqueue_active(&ctx->wait)) - wake_up(&ctx->wait); -} - static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx, struct io_submit_state *state) { @@ -646,7 +638,7 @@ static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx, req->result = 0; return req; out: - io_ring_drop_ctx_refs(ctx, 1); + percpu_ref_put(&ctx->refs); return NULL; } @@ -654,7 +646,7 @@ static void io_free_req_many(struct io_ring_ctx *ctx, void **reqs, int *nr) { if (*nr) { kmem_cache_free_bulk(req_cachep, *nr, reqs); - io_ring_drop_ctx_refs(ctx, *nr); + percpu_ref_put_many(&ctx->refs, *nr); *nr = 0; } } @@ -663,7 +655,7 @@ static void __io_free_req(struct io_kiocb *req) { if (req->file && !(req->flags & REQ_F_FIXED_FILE)) fput(req->file); - io_ring_drop_ctx_refs(req->ctx, 1); + percpu_ref_put(&req->ctx->refs); kmem_cache_free(req_cachep, req); } @@ -3630,7 +3622,7 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, } } - io_ring_drop_ctx_refs(ctx, 1); + percpu_ref_put(&ctx->refs); out_fput: fdput(f); return submitted ? submitted : ret; -- 2.23.0
