From 3ab665b74e59ad467b3eab5b2b95d378cea78b22 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Fri, 24 Sep 2021 21:59:45 +0100 Subject: [PATCH] io_uring: remove allocation cache array We have several of request allocation layers, remove the last one, which is the submit->reqs array, and always use submit->free_reqs instead. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/8547095c35f7a87bab14f6447ecd30a273ed7500.1632516769.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- fs/io_uring.c | 60 +++++++++++++++++------------------------------------------ 1 file changed, 17 insertions(+), 43 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 0ccfd70af3e0..e3bfbd3f4787 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -310,12 +310,6 @@ struct io_submit_state { struct blk_plug plug; struct io_submit_link link; - /* - * io_kiocb alloc cache - */ - void *reqs[IO_REQ_CACHE_SIZE]; - unsigned int free_reqs; - bool plug_started; bool need_plug; @@ -1898,7 +1892,6 @@ static void io_flush_cached_locked_reqs(struct io_ring_ctx *ctx, static bool io_flush_cached_reqs(struct io_ring_ctx *ctx) { struct io_submit_state *state = &ctx->submit_state; - int nr; /* * If we have more than a batch's worth of requests in our IRQ side @@ -1907,20 +1900,7 @@ static bool io_flush_cached_reqs(struct io_ring_ctx *ctx) */ if (READ_ONCE(ctx->locked_free_nr) > IO_COMPL_BATCH) io_flush_cached_locked_reqs(ctx, state); - - nr = state->free_reqs; - while (!list_empty(&state->free_list)) { - struct io_kiocb *req = list_first_entry(&state->free_list, - struct io_kiocb, inflight_entry); - - list_del(&req->inflight_entry); - state->reqs[nr++] = req; - if (nr == ARRAY_SIZE(state->reqs)) - break; - } - - state->free_reqs = nr; - return nr != 0; + return !list_empty(&state->free_list); } /* @@ -1934,33 +1914,36 @@ static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx) { struct io_submit_state *state = &ctx->submit_state; gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; + void *reqs[IO_REQ_ALLOC_BATCH]; + struct io_kiocb *req; int ret, i; - BUILD_BUG_ON(ARRAY_SIZE(state->reqs) < IO_REQ_ALLOC_BATCH); - - if (likely(state->free_reqs || io_flush_cached_reqs(ctx))) + if (likely(!list_empty(&state->free_list) || io_flush_cached_reqs(ctx))) goto got_req; - ret = kmem_cache_alloc_bulk(req_cachep, gfp, IO_REQ_ALLOC_BATCH, - state->reqs); + ret = kmem_cache_alloc_bulk(req_cachep, gfp, ARRAY_SIZE(reqs), reqs); /* * Bulk alloc is all-or-nothing. If we fail to get a batch, * retry single alloc to be on the safe side. */ if (unlikely(ret <= 0)) { - state->reqs[0] = kmem_cache_alloc(req_cachep, gfp); - if (!state->reqs[0]) + reqs[0] = kmem_cache_alloc(req_cachep, gfp); + if (!reqs[0]) return NULL; ret = 1; } - for (i = 0; i < ret; i++) - io_preinit_req(state->reqs[i], ctx); - state->free_reqs = ret; + for (i = 0; i < ret; i++) { + req = reqs[i]; + + io_preinit_req(req, ctx); + list_add(&req->inflight_entry, &state->free_list); + } got_req: - state->free_reqs--; - return state->reqs[state->free_reqs]; + req = list_first_entry(&state->free_list, struct io_kiocb, inflight_entry); + list_del(&req->inflight_entry); + return req; } static inline void io_put_file(struct file *file) @@ -2318,10 +2301,7 @@ static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req, rb->task_refs++; rb->ctx_refs++; - if (state->free_reqs != ARRAY_SIZE(state->reqs)) - state->reqs[state->free_reqs++] = req; - else - list_add(&req->inflight_entry, &state->free_list); + list_add(&req->inflight_entry, &state->free_list); } static void __io_submit_flush_completions(struct io_ring_ctx *ctx) @@ -9228,12 +9208,6 @@ static void io_req_caches_free(struct io_ring_ctx *ctx) struct io_submit_state *state = &ctx->submit_state; mutex_lock(&ctx->uring_lock); - - if (state->free_reqs) { - kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs); - state->free_reqs = 0; - } - io_flush_cached_locked_reqs(ctx, state); io_req_cache_free(&state->free_list); mutex_unlock(&ctx->uring_lock); -- 2.11.0