From: Pavel Begunkov Date: Wed, 5 Feb 2025 11:36:42 +0000 (+0000) Subject: io_uring/kbuf: remove legacy kbuf bulk allocation X-Git-Tag: for-6.15/io_uring-20250322~99 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=7919292a961421bfdb22f83c16657684c96076b3;p=linux-block.git io_uring/kbuf: remove legacy kbuf bulk allocation Legacy provided buffers are slow and discouraged in favour of the ring variant. Remove the bulk allocation to keep it simpler as we don't care about performance. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/a064d70370e590efed8076e9501ae4cfc20fe0ca.1738724373.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index 8e72de7712ac..f152afdf0bc7 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -501,12 +501,9 @@ int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe return 0; } -#define IO_BUFFER_ALLOC_BATCH 64 - static int io_refill_buffer_cache(struct io_ring_ctx *ctx) { - struct io_buffer *bufs[IO_BUFFER_ALLOC_BATCH]; - int allocated; + struct io_buffer *buf; /* * Completions that don't happen inline (eg not under uring_lock) will @@ -524,27 +521,10 @@ static int io_refill_buffer_cache(struct io_ring_ctx *ctx) spin_unlock(&ctx->completion_lock); } - /* - * No free buffers and no completion entries either. Allocate a new - * batch of buffer entries and add those to our freelist. - */ - - allocated = kmem_cache_alloc_bulk(io_buf_cachep, GFP_KERNEL_ACCOUNT, - ARRAY_SIZE(bufs), (void **) bufs); - if (unlikely(!allocated)) { - /* - * Bulk alloc is all-or-nothing. If we fail to get a batch, - * retry single alloc to be on the safe side. - */ - bufs[0] = kmem_cache_alloc(io_buf_cachep, GFP_KERNEL); - if (!bufs[0]) - return -ENOMEM; - allocated = 1; - } - - while (allocated) - list_add_tail(&bufs[--allocated]->list, &ctx->io_buffers_cache); - + buf = kmem_cache_alloc(io_buf_cachep, GFP_KERNEL); + if (!buf) + return -ENOMEM; + list_add_tail(&buf->list, &ctx->io_buffers_cache); return 0; }