From patchwork Thu Oct 24 13:19:42 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 13850723 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C613BD0C610 for ; Fri, 25 Oct 2024 13:33:34 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C7FAF10EADE; Fri, 25 Oct 2024 13:33:32 +0000 (UTC) Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2095410E94C; Thu, 24 Oct 2024 13:41:50 +0000 (UTC) Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4XZ6661sy8z4f3jdc; Thu, 24 Oct 2024 21:22:38 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id B4AD81A0359; Thu, 24 Oct 2024 21:22:55 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgCHusYpShpn7tb6Ew--.444S5; Thu, 24 Oct 2024 21:22:54 +0800 (CST) From: Yu Kuai To: stable@vger.kernel.org, gregkh@linuxfoundation.org, harry.wentland@amd.com, sunpeng.li@amd.com, Rodrigo.Siqueira@amd.com, alexander.deucher@amd.com, christian.koenig@amd.com, Xinhui.Pan@amd.com, airlied@gmail.com, daniel@ffwll.ch, viro@zeniv.linux.org.uk, brauner@kernel.org, Liam.Howlett@oracle.com, akpm@linux-foundation.org, hughd@google.com, willy@infradead.org, sashal@kernel.org, srinivasan.shanmugam@amd.com, chiahsuan.chung@amd.com, mingo@kernel.org, mgorman@techsingularity.net, yukuai3@huawei.com, chengming.zhou@linux.dev, zhangpeng.00@bytedance.com, chuck.lever@oracle.com Cc: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, maple-tree@lists.infradead.org, linux-mm@kvack.org, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com Subject: [PATCH 6.6 01/28] maple_tree: add mt_free_one() and mt_attr() helpers Date: Thu, 24 Oct 2024 21:19:42 +0800 Message-Id: <20241024132009.2267260-2-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20241024132009.2267260-1-yukuai1@huaweicloud.com> References: <20241024132009.2267260-1-yukuai1@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgCHusYpShpn7tb6Ew--.444S5 X-Coremail-Antispam: 1UD129KBjvJXoWxZryUtF17GFWUCw4xuw48WFg_yoWrur4kpr ZrK345tFsavr18G3yxKa1UJ34rXFs3X3yjqa4qkw1DA3Z8Ar1SqFyIv3yrZFWfu3ykG3W3 Ar4qgw18CF4qyFJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUmI14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jr4l82xGYIkIc2 x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS 0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2 IY67AKxVWUGVWUXwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0 Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2kIc2 xKxwCY1x0262kKe7AKxVWrXVW3AwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWU JVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67 kF1VAFwI0_Wrv_Gr1UMIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_JFI_Gr1lIxAI cVC0I7IYx2IY6xkF7I0E14v26r4UJVWxJr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMI IF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr1j6F4UJbIYCTnI WIevJa73UjIFyTuYvjTRCpBTUUUUU X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ X-Mailman-Approved-At: Fri, 25 Oct 2024 13:32:50 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Peng Zhang commit 4f2267b58a22d972be98edef8e6b3c7a67c9fb91 upstream. Patch series "Introduce __mt_dup() to improve the performance of fork()", v7. This series introduces __mt_dup() to improve the performance of fork(). During the duplication process of mmap, all VMAs are traversed and inserted one by one into the new maple tree, causing the maple tree to be rebalanced multiple times. Balancing the maple tree is a costly operation. To duplicate VMAs more efficiently, mtree_dup() and __mt_dup() are introduced for the maple tree. They can efficiently duplicate a maple tree. Here are some algorithmic details about {mtree,__mt}_dup(). We perform a DFS pre-order traversal of all nodes in the source maple tree. During this process, we fully copy the nodes from the source tree to the new tree. This involves memory allocation, and when encountering a new node, if it is a non-leaf node, all its child nodes are allocated at once. This idea was originally from Liam R. Howlett's Maple Tree Work email, and I added some of my own ideas to implement it. Some previous discussions can be found in [1]. For a more detailed analysis of the algorithm, please refer to the logs for patch [3/10] and patch [10/10]. There is a "spawn" in byte-unixbench[2], which can be used to test the performance of fork(). I modified it slightly to make it work with different number of VMAs. Below are the test results. The first row shows the number of VMAs. The second and third rows show the number of fork() calls per ten seconds, corresponding to next-20231006 and the this patchset, respectively. The test results were obtained with CPU binding to avoid scheduler load balancing that could cause unstable results. There are still some fluctuations in the test results, but at least they are better than the original performance. 21 121 221 421 821 1621 3221 6421 12821 25621 51221 112100 76261 54227 34035 20195 11112 6017 3161 1606 802 393 114558 83067 65008 45824 28751 16072 8922 4747 2436 1233 599 2.19% 8.92% 19.88% 34.64% 42.37% 44.64% 48.28% 50.17% 51.68% 53.74% 52.42% Thanks to Liam and Matthew for the review. This patch (of 10): Add two helpers: 1. mt_free_one(), used to free a maple node. 2. mt_attr(), used to obtain the attributes of maple tree. Link: https://lkml.kernel.org/r/20231027033845.90608-1-zhangpeng.00@bytedance.com Link: https://lkml.kernel.org/r/20231027033845.90608-2-zhangpeng.00@bytedance.com Signed-off-by: Peng Zhang Reviewed-by: Liam R. Howlett Cc: Christian Brauner Cc: Jonathan Corbet Cc: Mateusz Guzik Cc: Mathieu Desnoyers Cc: Matthew Wilcox Cc: Michael S. Tsirkin Cc: Mike Christie Cc: Nicholas Piggin Cc: Peter Zijlstra Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton Signed-off-by: Yu Kuai --- lib/maple_tree.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/lib/maple_tree.c b/lib/maple_tree.c index 4e05511c8d1e..e7228bb86ef6 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -165,6 +165,11 @@ static inline int mt_alloc_bulk(gfp_t gfp, size_t size, void **nodes) return kmem_cache_alloc_bulk(maple_node_cache, gfp, size, nodes); } +static inline void mt_free_one(struct maple_node *node) +{ + kmem_cache_free(maple_node_cache, node); +} + static inline void mt_free_bulk(size_t size, void __rcu **nodes) { kmem_cache_free_bulk(maple_node_cache, size, (void **)nodes); @@ -205,6 +210,11 @@ static unsigned int mas_mt_height(struct ma_state *mas) return mt_height(mas->tree); } +static inline unsigned int mt_attr(struct maple_tree *mt) +{ + return mt->ma_flags & ~MT_FLAGS_HEIGHT_MASK; +} + static inline enum maple_type mte_node_type(const struct maple_enode *entry) { return ((unsigned long)entry >> MAPLE_NODE_TYPE_SHIFT) & @@ -5584,7 +5594,7 @@ void mas_destroy(struct ma_state *mas) mt_free_bulk(count, (void __rcu **)&node->slot[1]); total -= count; } - kmem_cache_free(maple_node_cache, node); + mt_free_one(ma_mnode_ptr(node)); total--; }