From patchwork Mon Dec 20 08:56:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 12687381 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 5FBE2C433EF for ; Mon, 20 Dec 2021 08:57:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238116AbhLTI5N (ORCPT ); Mon, 20 Dec 2021 03:57:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37130 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238113AbhLTI5N (ORCPT ); Mon, 20 Dec 2021 03:57:13 -0500 Received: from mail-pg1-x52e.google.com (mail-pg1-x52e.google.com [IPv6:2607:f8b0:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0C771C06173F for ; Mon, 20 Dec 2021 00:57:13 -0800 (PST) Received: by mail-pg1-x52e.google.com with SMTP id r5so8805033pgi.6 for ; Mon, 20 Dec 2021 00:57:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=fRj/9FIIki/mj5XneuiirdQw0O2G4BK0XEjt6ww0jfs=; b=IkDFaLeQTXbh4xqB2+eeQIS6+LFRLLj+EbszkeO6/PDP92AxBsbft5EbyvXiA7eSE4 LTBpHD9XyNriu7KV9nhblvVnB6h8LdeT62qh5utA8obRFLuQEqCJ9rbxuPkPcgl39s42 byRdIpT3Z9LrK+XWR6K0zZ2VOVfZ83eC7sLUB2t+PNwchV6lDz8vwgBE+LANmq2hpywI r6dxTckgFRPz0Mg4bhvsyg1MLHJtLbuz5TdXVlgmx5BxDJHF7+h12vF5H0VuYnljAPGS 8penXUk7OvXiXvrwBVKjtPFk2TT3H7zv5my/+wwk+8FdbiRoNbAhlajNAjOe04MyfHWr Bocg== 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:mime-version :content-transfer-encoding; bh=fRj/9FIIki/mj5XneuiirdQw0O2G4BK0XEjt6ww0jfs=; b=eGWtwgpIK3f1bfGIWdqzN/0YD5TtjtKiASle/7m9fP5dAh4cKy5fb/3Vkz83c5QdH6 gKhFI+kRWcnLO9c9ANcMVGP8bROFC91Zp/eZuZrQWdNODg4quCCyD7vLEU2p0sRzcnWV e1nksq5xIDAvHjcBeVYSptEUzlc0lC8xYHG3TM4xXbWsinw4Pjto0yAO6VoZSjKgPAii KHPJncanY+EUAx6MBoZ+JzOdTenCnvnWu3yJeqf0wl+xsKhexk3dTuzKFyfht3FtdQOT kXGc6amQkI/R++svxXaivEyUdYnaNv9qUtaqeqAAP75RDiseWSGCnUF+uGusTSWuT2g2 8jew== X-Gm-Message-State: AOAM531psxzXKLBNxrPgAM5dIH6Mou90P3Wsw8BAFhtVJBgiXuh9saXV IKG/RmFMa+A9POe/Q0LpumVa4Q== X-Google-Smtp-Source: ABdhPJyex2w+kvwNFCmu9uwGCkJuPKgsfqne7nlgorejT2LPnaUf7mULo4gG/ydeud2//sGbVNjMLg== X-Received: by 2002:a05:6a00:c88:b0:4ba:96e9:ffdc with SMTP id a8-20020a056a000c8800b004ba96e9ffdcmr10917315pfv.33.1639990632523; Mon, 20 Dec 2021 00:57:12 -0800 (PST) Received: from localhost.localdomain ([61.120.150.70]) by smtp.gmail.com with ESMTPSA id m11sm18441647pfk.27.2021.12.20.00.57.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 20 Dec 2021 00:57:12 -0800 (PST) From: Muchun Song To: willy@infradead.org, akpm@linux-foundation.org, hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com, shakeelb@google.com, guro@fb.com, shy828301@gmail.com, alexs@kernel.org, richard.weiyang@gmail.com, david@fromorbit.com, trond.myklebust@hammerspace.com, anna.schumaker@netapp.com, jaegeuk@kernel.org, chao@kernel.org, kari.argillander@gmail.com Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-nfs@vger.kernel.org, zhengqi.arch@bytedance.com, duanxiongchun@bytedance.com, fam.zheng@bytedance.com, smuchun@gmail.com, Muchun Song Subject: [PATCH v5 00/16] Optimize list lru memory consumption Date: Mon, 20 Dec 2021 16:56:33 +0800 Message-Id: <20211220085649.8196-1-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This series is based on Linux 5.16-rc3. In our server, we found a suspected memory leak problem. The kmalloc-32 consumes more than 6GB of memory. Other kmem_caches consume less than 2GB memory. After our in-depth analysis, the memory consumption of kmalloc-32 slab cache is the cause of list_lru_one allocation. crash> p memcg_nr_cache_ids memcg_nr_cache_ids = $2 = 24574 memcg_nr_cache_ids is very large and memory consumption of each list_lru can be calculated with the following formula. num_numa_node * memcg_nr_cache_ids * 32 (kmalloc-32) There are 4 numa nodes in our system, so each list_lru consumes ~3MB. crash> list super_blocks | wc -l 952 Every mount will register 2 list lrus, one is for inode, another is for dentry. There are 952 super_blocks. So the total memory is 952 * 2 * 3 MB (~5.6GB). But now the number of memory cgroups is less than 500. So I guess more than 12286 memory cgroups have been created on this machine (I do not know why there are so many cgroups, it may be a user's bug or the user really want to do that). Because memcg_nr_cache_ids has not been reduced to a suitable value. It leads to waste a lot of memory. If we want to reduce memcg_nr_cache_ids, we have to *reboot* the server. This is not what we want. In order to reduce memcg_nr_cache_ids, I had posted a patchset [1] to do this. But this did not fundamentally solve the problem. We currently allocate scope for every memcg to be able to tracked on every superblock instantiated in the system, regardless of whether that superblock is even accessible to that memcg. These huge memcg counts come from container hosts where memcgs are confined to just a small subset of the total number of superblocks that instantiated at any given point in time. For these systems with huge container counts, list_lru does not need the capability of tracking every memcg on every superblock. What it comes down to is that the list_lru is only needed for a given memcg if that memcg is instatiating and freeing objects on a given list_lru. As Dave said, "Which makes me think we should be moving more towards 'add the memcg to the list_lru at the first insert' model rather than 'instantiate all at memcg init time just in case'." This patchset aims to optimize the list lru memory consumption from different aspects. I had done a easy test to show the optimization. I create 10k memory cgroups and mount 10k filesystems in the systems. We use free command to show how many memory does the systems comsumes after this operation (There are 2 numa nodes in the system). +-----------------------+------------------------+ | condition | memory consumption | +-----------------------+------------------------+ | without this patchset | 24464 MB | +-----------------------+------------------------+ | after patch 1 | 21957 MB | <--------+ +-----------------------+------------------------+ | | after patch 11 | 6895 MB | | +-----------------------+------------------------+ | | after patch 13 | 4367 MB | | +-----------------------+------------------------+ | | The more the number of nodes, the more obvious the effect---+ BTW, there was a recent discussion [2] on the same issue. [1] https://lore.kernel.org/linux-fsdevel/20210428094949.43579-1-songmuchun@bytedance.com/ [2] https://lore.kernel.org/linux-fsdevel/20210405054848.GA1077931@in.ibm.com/ This series not only optimizes the memory usage of list_lru but also simplifies the code. Changelog in v5: - Fix sleeping from atomic context reported by kernel test robot. - Add a figure to patch 1 suggested by Johannes. - Squash patch 9 into patch 8 suggested by Johannes. - Remove LRUS_CLEAR_MASK and use GFP_RECLAIM_MASK directly suggested by Johannes. - Collect Acked-by from Johannes. Thanks. Changelog in v4: - Remove some code cleanup patches since they are already merged. - Collect Acked-by from Theodore. Changelog in v3: - Fix mixing advanced and normal XArray concepts (Thanks to Matthew). - Split one patch into per-filesystem patches. Changelog in v2: - Update Documentation/filesystems/porting.rst suggested by Dave. - Add a comment above alloc_inode_sb() suggested by Dave. - Rework some patch's commit log. - Add patch 18-21. Thanks Dave. Muchun Song (16): mm: list_lru: optimize memory consumption of arrays of per cgroup lists mm: introduce kmem_cache_alloc_lru fs: introduce alloc_inode_sb() to allocate filesystems specific inode fs: allocate inode by using alloc_inode_sb() f2fs: allocate inode by using alloc_inode_sb() nfs42: use a specific kmem_cache to allocate nfs4_xattr_entry mm: dcache: use kmem_cache_alloc_lru() to allocate dentry xarray: use kmem_cache_alloc_lru to allocate xa_node mm: memcontrol: move memcg_online_kmem() to mem_cgroup_css_online() mm: list_lru: allocate list_lru_one only when needed mm: list_lru: rename memcg_drain_all_list_lrus to memcg_reparent_list_lrus mm: list_lru: replace linear array with xarray mm: memcontrol: reuse memory cgroup ID for kmem ID mm: memcontrol: fix cannot alloc the maximum memcg ID mm: list_lru: rename list_lru_per_memcg to list_lru_memcg mm: memcontrol: rename memcg_cache_id to memcg_kmem_id Documentation/filesystems/porting.rst | 5 + block/bdev.c | 2 +- drivers/dax/super.c | 2 +- fs/9p/vfs_inode.c | 2 +- fs/adfs/super.c | 2 +- fs/affs/super.c | 2 +- fs/afs/super.c | 2 +- fs/befs/linuxvfs.c | 2 +- fs/bfs/inode.c | 2 +- fs/btrfs/inode.c | 2 +- fs/ceph/inode.c | 2 +- fs/cifs/cifsfs.c | 2 +- fs/coda/inode.c | 2 +- fs/dcache.c | 3 +- fs/ecryptfs/super.c | 2 +- fs/efs/super.c | 2 +- fs/erofs/super.c | 2 +- fs/exfat/super.c | 2 +- fs/ext2/super.c | 2 +- fs/ext4/super.c | 2 +- fs/f2fs/super.c | 8 +- fs/fat/inode.c | 2 +- fs/freevxfs/vxfs_super.c | 2 +- fs/fuse/inode.c | 2 +- fs/gfs2/super.c | 2 +- fs/hfs/super.c | 2 +- fs/hfsplus/super.c | 2 +- fs/hostfs/hostfs_kern.c | 2 +- fs/hpfs/super.c | 2 +- fs/hugetlbfs/inode.c | 2 +- fs/inode.c | 2 +- fs/isofs/inode.c | 2 +- fs/jffs2/super.c | 2 +- fs/jfs/super.c | 2 +- fs/minix/inode.c | 2 +- fs/nfs/inode.c | 2 +- fs/nfs/nfs42xattr.c | 95 ++++---- fs/nilfs2/super.c | 2 +- fs/ntfs/inode.c | 2 +- fs/ntfs3/super.c | 2 +- fs/ocfs2/dlmfs/dlmfs.c | 2 +- fs/ocfs2/super.c | 2 +- fs/openpromfs/inode.c | 2 +- fs/orangefs/super.c | 2 +- fs/overlayfs/super.c | 2 +- fs/proc/inode.c | 2 +- fs/qnx4/inode.c | 2 +- fs/qnx6/inode.c | 2 +- fs/reiserfs/super.c | 2 +- fs/romfs/super.c | 2 +- fs/squashfs/super.c | 2 +- fs/sysv/inode.c | 2 +- fs/ubifs/super.c | 2 +- fs/udf/super.c | 2 +- fs/ufs/super.c | 2 +- fs/vboxsf/super.c | 2 +- fs/xfs/xfs_icache.c | 2 +- fs/zonefs/super.c | 2 +- include/linux/fs.h | 11 + include/linux/list_lru.h | 17 +- include/linux/memcontrol.h | 42 ++-- include/linux/slab.h | 3 + include/linux/swap.h | 5 +- include/linux/xarray.h | 9 +- ipc/mqueue.c | 2 +- lib/xarray.c | 10 +- mm/list_lru.c | 417 ++++++++++++++++------------------ mm/memcontrol.c | 164 +++---------- mm/shmem.c | 2 +- mm/slab.c | 39 +++- mm/slab.h | 25 +- mm/slob.c | 6 + mm/slub.c | 42 ++-- mm/workingset.c | 2 +- net/socket.c | 2 +- net/sunrpc/rpc_pipe.c | 2 +- 76 files changed, 480 insertions(+), 539 deletions(-)