From patchwork Fri Jul 8 13:30:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 12911161 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4AE98C433EF for ; Fri, 8 Jul 2022 13:30:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238183AbiGHNag (ORCPT ); Fri, 8 Jul 2022 09:30:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36640 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237827AbiGHNac (ORCPT ); Fri, 8 Jul 2022 09:30:32 -0400 Received: from mail-pl1-x634.google.com (mail-pl1-x634.google.com [IPv6:2607:f8b0:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 83C2F2CDD0 for ; Fri, 8 Jul 2022 06:30:31 -0700 (PDT) Received: by mail-pl1-x634.google.com with SMTP id f11so3815934plr.4 for ; Fri, 08 Jul 2022 06:30:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=IVdTfss5KaSAak1AOrGr/5IMWzulflFQjH6JxUOu+Vk=; b=c6W4keu7lJCtMbmRmlL+4OUqaFt05ytd2v8ccXyK5ndAcfLq9O8Tcvrgd8i64WUUB4 cwOVBqOoZtJ5hlILICrdXzD215ShaN5b3iEmPccCKwUHkErNheyPEkrqni1ocDITGNYN IjMKwEF5ZSfFnApDXsPBtICiNjOTJNfIjCQfJxoo9siXZMyWe1QwNdpfhCH5ibGPhnsq BWujmI/zjXS71B8EdkgKL9ye5cI2QpnxoCAaKqKN+oFi1JLHPZHjEzc9WtnQGaGyo+IR N9LuwzeVhQvLIQtnv/0vCq7vLgTuqSjoWq+41xnYvGS2xNp7hlBTy8tw3xsYG8BaU33Z wqsQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=IVdTfss5KaSAak1AOrGr/5IMWzulflFQjH6JxUOu+Vk=; b=DBsuK0KpxnV+B1atktUbrd5NfMF/qJQtA7VWij3RTioPbD8EXZKbM+AufqghJYMJcs 6OndLFDcxZL1S9Z/CZa6nNGq2Io9jezT8AwW8LGAM+EWEGjmFgqP8Mi/rOAyAe5PJY7z WPMQRC4jLL2ivTndvMrN5ECH4TMpPWH+7sDa4TZDxRglEUcSzhtyxheeuQ7pJZKdUB9x GOD1UrFLL/SlU96W1ktoBnzSfc6x11/9kXhjL/D8EbbxDi3xlrPCEJeCopQPS7V9lnLI xtQ2UQ5LIScan4v4m25aYzvmF47rQVviyzSaAFn871KDivWDYoqcjFWdKsrGiVdbTeKU nxFA== X-Gm-Message-State: AJIora9nSjPi03M0G7m93ajeYIJab27z8js4UlB79WQcQ/3sSNVMUzIj 0ebi5sZBMv+/OKbaLxBFvsqxbxfuSoFUQw== X-Google-Smtp-Source: AGRyM1tfHXCCyJg1Zojl1A5XmPoJnz1FGkYSXIDxkKmMO5rNOsJe6ZouyTKAwY12EAa+1W65zugtlQ== X-Received: by 2002:a17:902:c947:b0:16b:f442:8568 with SMTP id i7-20020a170902c94700b0016bf4428568mr3759288pla.55.1657287030759; Fri, 08 Jul 2022 06:30:30 -0700 (PDT) Received: from localhost.localdomain ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id a16-20020aa794b0000000b0052844157f09sm3800502pfl.51.2022.07.08.06.30.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 08 Jul 2022 06:30:30 -0700 (PDT) From: Jens Axboe To: io-uring@vger.kernel.org Cc: asml.silence@gmail.com, dylany@fb.com, Jens Axboe Subject: [PATCH 3/4] io_uring: impose max limit on apoll cache Date: Fri, 8 Jul 2022 07:30:21 -0600 Message-Id: <20220708133022.383961-4-axboe@kernel.dk> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220708133022.383961-1-axboe@kernel.dk> References: <20220708133022.383961-1-axboe@kernel.dk> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Caches like this tend to grow to the peak size, and then never get any smaller. Impose a max limit on the size, to prevent it from growing too big. A somewhat randomly chosen 512 is the max size we'll allow the cache to get. If a batch of frees come in and would bring it over that, we simply start kfree'ing the surplus. Signed-off-by: Jens Axboe --- include/linux/io_uring_types.h | 1 + io_uring/alloc_cache.h | 16 ++++++++++++++-- io_uring/io_uring.c | 3 ++- 3 files changed, 17 insertions(+), 3 deletions(-) diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index b548da03b563..bf8f95332eda 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -160,6 +160,7 @@ struct io_ev_fd { struct io_alloc_cache { struct hlist_head list; + unsigned int nr_cached; }; struct io_ring_ctx { diff --git a/io_uring/alloc_cache.h b/io_uring/alloc_cache.h index 98f2374c37c7..729793ae9712 100644 --- a/io_uring/alloc_cache.h +++ b/io_uring/alloc_cache.h @@ -1,14 +1,24 @@ #ifndef IOU_ALLOC_CACHE_H #define IOU_ALLOC_CACHE_H +/* + * Don't allow the cache to grow beyond this size. + */ +#define IO_ALLOC_CACHE_MAX 512 + struct io_cache_entry { struct hlist_node node; }; -static inline void io_alloc_cache_put(struct io_alloc_cache *cache, +static inline bool io_alloc_cache_put(struct io_alloc_cache *cache, struct io_cache_entry *entry) { - hlist_add_head(&entry->node, &cache->list); + if (cache->nr_cached < IO_ALLOC_CACHE_MAX) { + cache->nr_cached++; + hlist_add_head(&entry->node, &cache->list); + return true; + } + return false; } static inline struct io_cache_entry *io_alloc_cache_get(struct io_alloc_cache *cache) @@ -26,6 +36,7 @@ static inline struct io_cache_entry *io_alloc_cache_get(struct io_alloc_cache *c static inline void io_alloc_cache_init(struct io_alloc_cache *cache) { INIT_HLIST_HEAD(&cache->list); + cache->nr_cached = 0; } static inline void io_alloc_cache_free(struct io_alloc_cache *cache, @@ -37,5 +48,6 @@ static inline void io_alloc_cache_free(struct io_alloc_cache *cache, hlist_del(node); free(container_of(node, struct io_cache_entry, node)); } + cache->nr_cached = 0; } #endif diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index a360a3d390c6..c9c23e459766 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -1181,7 +1181,8 @@ void io_free_batch_list(struct io_ring_ctx *ctx, struct io_wq_work_node *node) if (apoll->double_poll) kfree(apoll->double_poll); - io_alloc_cache_put(&ctx->apoll_cache, &apoll->cache); + if (!io_alloc_cache_put(&ctx->apoll_cache, &apoll->cache)) + kfree(apoll); req->flags &= ~REQ_F_POLLED; } if (req->flags & IO_REQ_LINK_FLAGS)