Commit d9713ad3 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: remove async request cache 



io_req_complete_post() was a sole user of ->locked_free_list, but
since we just gutted the function, the cache is not used anymore and
can be removed.

->locked_free_list served as an asynhronous counterpart of the main
request (i.e. struct io_kiocb) cache for all unlocked cases like io-wq.
Now they're all forced to be completed into the main cache directly,
off of the normal completion path or via io_free_req().

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7bffccd213e370abd4de480e739d8b08ab6c1326.1712331455.git.asml.silence@gmail.com


Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent de96e9ae

include/linux/io_uring_types.h

+0 −4
Original line number Diff line number Diff line
@@ -346,10 +346,6 @@ struct io_ring_ctx { 


	spinlock_t		completion_lock;



	/* IRQ completion list, under ->completion_lock */

	unsigned int		locked_free_nr;

	struct io_wq_work_list	locked_free_list;



	struct list_head	io_buffers_comp;

	struct list_head	cq_overflow_list;

	struct io_hash_table	cancel_table;

io_uring/io_uring.c

+0 −22
Original line number Diff line number Diff line
@@ -334,7 +334,6 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) 
	init_llist_head(&ctx->work_llist);

	INIT_LIST_HEAD(&ctx->tctx_list);

	ctx->submit_state.free_list.next = NULL;

	INIT_WQ_LIST(&ctx->locked_free_list);

	INIT_HLIST_HEAD(&ctx->waitid_list);

#ifdef CONFIG_FUTEX

	INIT_HLIST_HEAD(&ctx->futex_list);
@@ -988,15 +987,6 @@ static void io_preinit_req(struct io_kiocb *req, struct io_ring_ctx *ctx) 
	memset(&req->big_cqe, 0, sizeof(req->big_cqe));

}



static void io_flush_cached_locked_reqs(struct io_ring_ctx *ctx,

					struct io_submit_state *state)

{

	spin_lock(&ctx->completion_lock);

	wq_list_splice(&ctx->locked_free_list, &state->free_list);

	ctx->locked_free_nr = 0;

	spin_unlock(&ctx->completion_lock);

}



/*

 * A request might get retired back into the request caches even before opcode

 * handlers and io_issue_sqe() are done with it, e.g. inline completion path.
@@ -1010,17 +1000,6 @@ __cold bool __io_alloc_req_refill(struct io_ring_ctx *ctx) 
	void *reqs[IO_REQ_ALLOC_BATCH];

	int ret;



	/*

	 * If we have more than a batch's worth of requests in our IRQ side

	 * locked cache, grab the lock and move them over to our submission

	 * side cache.

	 */

	if (data_race(ctx->locked_free_nr) > IO_COMPL_BATCH) {

		io_flush_cached_locked_reqs(ctx, &ctx->submit_state);

		if (!io_req_cache_empty(ctx))

			return true;

	}



	ret = kmem_cache_alloc_bulk(req_cachep, gfp, ARRAY_SIZE(reqs), reqs);



	/*
@@ -2654,7 +2633,6 @@ static void io_req_caches_free(struct io_ring_ctx *ctx) 
	int nr = 0;



	mutex_lock(&ctx->uring_lock);

	io_flush_cached_locked_reqs(ctx, &ctx->submit_state);



	while (!io_req_cache_empty(ctx)) {

		req = io_extract_req(ctx);