From patchwork Mon Aug 7 11:09:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qi Zheng X-Patchwork-Id: 13343976 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 938F2C001DF for ; Mon, 7 Aug 2023 11:39:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230138AbjHGLjF (ORCPT ); Mon, 7 Aug 2023 07:39:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232357AbjHGLik (ORCPT ); Mon, 7 Aug 2023 07:38:40 -0400 Received: from mail-vs1-xe30.google.com (mail-vs1-xe30.google.com [IPv6:2607:f8b0:4864:20::e30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3DBA04697 for ; Mon, 7 Aug 2023 04:35:18 -0700 (PDT) Received: by mail-vs1-xe30.google.com with SMTP id ada2fe7eead31-447cd538b0fso155459137.0 for ; Mon, 07 Aug 2023 04:35:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1691408065; x=1692012865; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=+T9zoPssix7N9qfaGNa68znQHEAFyeYciCKXdVaHQFo=; b=fVyosP2wrWvgJwhgbJ4qkpsvW+DJoGPjCDgm3I7Ij005Qst/IVp8mTdjXsnMZm2k7j NpMH3uu7GHEv6HZlGEiRTV1BgeF+tAfl3Mx36XEDZd+s6qRzTR0sVCeksEzLWfYYOP8W 5p2/4Vgkyp2UN8gbeBe3rMIe2w1Cc4psiUnVofIADHADrC/VZLXuH7L3WWVL/xIB9kct hz3EmtSZqAR0ddRqunjUt9TtGz9DIjiyMPkZuQapdn+kdPOeWEXAqRPhqtLDnmafMeol Q7ETB2F8x7KkB3MJulSMbb1TFKUCn6GVCtR2ob0sgIMiSpRcB1ABn44ImL5Qhn2Bk1e3 fG4Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691408065; x=1692012865; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=+T9zoPssix7N9qfaGNa68znQHEAFyeYciCKXdVaHQFo=; b=KvnJCwUWa4lJYZE/h+I6zhg+9kAo3sHUIuFoFLF7grr1CsEbHB1yJO9D9O6TN4t5Ni jhTGJK7DwOUagt34Iu2MB4uXMKfZqXPYpE4al74PR6blKTdpAQdH6ZXDzUOgMdcgX9+p ipjxU0oa/b6WeQUUDidcuYviuAh4i541UVh0RYaguAEGSP0ODaw0igtDjMNUyIK84H6g 9+wsShxGIr35Ij/+7iqkXstuu6ZcAXaJM+r3dxsyzDLJh+3HBOftnT44tL233fDOGTsy tAJwYvCGVfsupQtMol7QBRq5C3v/4gT1hVjicd3R04KOtzd7oSURLFFN5ASEvqC2RgOK Xy4A== X-Gm-Message-State: ABy/qLYXFzx4EePNp+4kr0IAeWJPkECDei8sjV1EvgeohBPpZh+aLHWb M26eFI/MW/HN32P4fcsAZGnxocQXVBvwYDODbvY= X-Google-Smtp-Source: AGHT+IF0evmdLrDlsDTr5Y4TU4NmdZynXgLSKug5uHjkOo8cedCVYEqxJp+s7Xi+ZKGxMcrB3jNS6g== X-Received: by 2002:a17:90a:648:b0:269:60ed:d493 with SMTP id q8-20020a17090a064800b0026960edd493mr1830877pje.4.1691407213020; Mon, 07 Aug 2023 04:20:13 -0700 (PDT) Received: from C02DW0BEMD6R.bytedance.net ([203.208.167.146]) by smtp.gmail.com with ESMTPSA id y13-20020a17090aca8d00b0025be7b69d73sm5861191pjt.12.2023.08.07.04.20.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Aug 2023 04:20:12 -0700 (PDT) From: Qi Zheng To: akpm@linux-foundation.org, david@fromorbit.com, tkhai@ya.ru, vbabka@suse.cz, roman.gushchin@linux.dev, djwong@kernel.org, brauner@kernel.org, paulmck@kernel.org, tytso@mit.edu, steven.price@arm.com, cel@kernel.org, senozhatsky@chromium.org, yujie.liu@intel.com, gregkh@linuxfoundation.org, muchun.song@linux.dev, simon.horman@corigine.com, dlemoal@kernel.org Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, kvm@vger.kernel.org, xen-devel@lists.xenproject.org, linux-erofs@lists.ozlabs.org, linux-f2fs-devel@lists.sourceforge.net, cluster-devel@redhat.com, linux-nfs@vger.kernel.org, linux-mtd@lists.infradead.org, rcu@vger.kernel.org, netdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, dm-devel@redhat.com, linux-raid@vger.kernel.org, linux-bcache@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, linux-btrfs@vger.kernel.org, Qi Zheng Subject: [PATCH v4 48/48] mm: shrinker: convert shrinker_rwsem to mutex Date: Mon, 7 Aug 2023 19:09:36 +0800 Message-Id: <20230807110936.21819-49-zhengqi.arch@bytedance.com> X-Mailer: git-send-email 2.24.3 (Apple Git-128) In-Reply-To: <20230807110936.21819-1-zhengqi.arch@bytedance.com> References: <20230807110936.21819-1-zhengqi.arch@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Now there are no readers of shrinker_rwsem, so we can simply replace it with mutex lock. Signed-off-by: Qi Zheng --- drivers/md/dm-cache-metadata.c | 2 +- fs/super.c | 2 +- mm/shrinker.c | 28 ++++++++++++++-------------- mm/shrinker_debug.c | 14 +++++++------- 4 files changed, 23 insertions(+), 23 deletions(-) diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c index acffed750e3e..9e0c69958587 100644 --- a/drivers/md/dm-cache-metadata.c +++ b/drivers/md/dm-cache-metadata.c @@ -1828,7 +1828,7 @@ int dm_cache_metadata_abort(struct dm_cache_metadata *cmd) * Replacement block manager (new_bm) is created and old_bm destroyed outside of * cmd root_lock to avoid ABBA deadlock that would result (due to life-cycle of * shrinker associated with the block manager's bufio client vs cmd root_lock). - * - must take shrinker_rwsem without holding cmd->root_lock + * - must take shrinker_mutex without holding cmd->root_lock */ new_bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT, CACHE_MAX_CONCURRENT_LOCKS); diff --git a/fs/super.c b/fs/super.c index a28193045345..60c2d290c754 100644 --- a/fs/super.c +++ b/fs/super.c @@ -54,7 +54,7 @@ static char *sb_writers_name[SB_FREEZE_LEVELS] = { * One thing we have to be careful of with a per-sb shrinker is that we don't * drop the last active reference to the superblock from within the shrinker. * If that happens we could trigger unregistering the shrinker from within the - * shrinker path and that leads to deadlock on the shrinker_rwsem. Hence we + * shrinker path and that leads to deadlock on the shrinker_mutex. Hence we * take a passive reference to the superblock to avoid this from occurring. */ static unsigned long super_cache_scan(struct shrinker *shrink, diff --git a/mm/shrinker.c b/mm/shrinker.c index a12dede5d21f..3d44a335ef3c 100644 --- a/mm/shrinker.c +++ b/mm/shrinker.c @@ -8,7 +8,7 @@ #include "internal.h" LIST_HEAD(shrinker_list); -DECLARE_RWSEM(shrinker_rwsem); +DEFINE_MUTEX(shrinker_mutex); #ifdef CONFIG_MEMCG static int shrinker_nr_max; @@ -80,7 +80,7 @@ int alloc_shrinker_info(struct mem_cgroup *memcg) int nid, ret = 0; int array_size = 0; - down_write(&shrinker_rwsem); + mutex_lock(&shrinker_mutex); array_size = shrinker_unit_size(shrinker_nr_max); for_each_node(nid) { info = kvzalloc_node(sizeof(*info) + array_size, GFP_KERNEL, nid); @@ -91,7 +91,7 @@ int alloc_shrinker_info(struct mem_cgroup *memcg) goto err; rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_info, info); } - up_write(&shrinker_rwsem); + mutex_unlock(&shrinker_mutex); return ret; @@ -104,7 +104,7 @@ static struct shrinker_info *shrinker_info_protected(struct mem_cgroup *memcg, int nid) { return rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_info, - lockdep_is_held(&shrinker_rwsem)); + lockdep_is_held(&shrinker_mutex)); } static struct shrinker_info *shrinker_info_rcu(struct mem_cgroup *memcg, @@ -161,7 +161,7 @@ static int expand_shrinker_info(int new_id) if (!root_mem_cgroup) goto out; - lockdep_assert_held(&shrinker_rwsem); + lockdep_assert_held(&shrinker_mutex); new_size = shrinker_unit_size(new_nr_max); old_size = shrinker_unit_size(shrinker_nr_max); @@ -224,7 +224,7 @@ static int shrinker_memcg_alloc(struct shrinker *shrinker) if (mem_cgroup_disabled()) return -ENOSYS; - down_write(&shrinker_rwsem); + mutex_lock(&shrinker_mutex); id = idr_alloc(&shrinker_idr, shrinker, 0, 0, GFP_KERNEL); if (id < 0) goto unlock; @@ -238,7 +238,7 @@ static int shrinker_memcg_alloc(struct shrinker *shrinker) shrinker->id = id; ret = 0; unlock: - up_write(&shrinker_rwsem); + mutex_unlock(&shrinker_mutex); return ret; } @@ -248,7 +248,7 @@ static void shrinker_memcg_remove(struct shrinker *shrinker) BUG_ON(id < 0); - lockdep_assert_held(&shrinker_rwsem); + lockdep_assert_held(&shrinker_mutex); idr_remove(&shrinker_idr, id); } @@ -299,7 +299,7 @@ void reparent_shrinker_deferred(struct mem_cgroup *memcg) parent = root_mem_cgroup; /* Prevent from concurrent shrinker_info expand */ - down_write(&shrinker_rwsem); + mutex_lock(&shrinker_mutex); for_each_node(nid) { child_info = shrinker_info_protected(memcg, nid); parent_info = shrinker_info_protected(parent, nid); @@ -312,7 +312,7 @@ void reparent_shrinker_deferred(struct mem_cgroup *memcg) } } } - up_write(&shrinker_rwsem); + mutex_unlock(&shrinker_mutex); } #else static int shrinker_memcg_alloc(struct shrinker *shrinker) @@ -708,11 +708,11 @@ void shrinker_register(struct shrinker *shrinker) return; } - down_write(&shrinker_rwsem); + mutex_lock(&shrinker_mutex); list_add_tail_rcu(&shrinker->list, &shrinker_list); shrinker->flags |= SHRINKER_REGISTERED; shrinker_debugfs_add(shrinker); - up_write(&shrinker_rwsem); + mutex_unlock(&shrinker_mutex); init_completion(&shrinker->done); /* @@ -745,7 +745,7 @@ void shrinker_free(struct shrinker *shrinker) wait_for_completion(&shrinker->done); } - down_write(&shrinker_rwsem); + mutex_lock(&shrinker_mutex); if (shrinker->flags & SHRINKER_REGISTERED) { /* * Lookups on the shrinker are over and will fail in the future, @@ -760,7 +760,7 @@ void shrinker_free(struct shrinker *shrinker) if (shrinker->flags & SHRINKER_MEMCG_AWARE) shrinker_memcg_remove(shrinker); - up_write(&shrinker_rwsem); + mutex_unlock(&shrinker_mutex); if (debugfs_entry) shrinker_debugfs_remove(debugfs_entry, debugfs_id); diff --git a/mm/shrinker_debug.c b/mm/shrinker_debug.c index aa2027075ed9..b698ca9e309e 100644 --- a/mm/shrinker_debug.c +++ b/mm/shrinker_debug.c @@ -7,7 +7,7 @@ #include /* defined in vmscan.c */ -extern struct rw_semaphore shrinker_rwsem; +extern struct mutex shrinker_mutex; extern struct list_head shrinker_list; static DEFINE_IDA(shrinker_debugfs_ida); @@ -163,7 +163,7 @@ int shrinker_debugfs_add(struct shrinker *shrinker) char buf[128]; int id; - lockdep_assert_held(&shrinker_rwsem); + lockdep_assert_held(&shrinker_mutex); /* debugfs isn't initialized yet, add debugfs entries later. */ if (!shrinker_debugfs_root) @@ -220,7 +220,7 @@ int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ...) if (!new) return -ENOMEM; - down_write(&shrinker_rwsem); + mutex_lock(&shrinker_mutex); old = shrinker->name; shrinker->name = new; @@ -238,7 +238,7 @@ int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ...) shrinker->debugfs_entry = entry; } - up_write(&shrinker_rwsem); + mutex_unlock(&shrinker_mutex); kfree_const(old); @@ -251,7 +251,7 @@ struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, { struct dentry *entry = shrinker->debugfs_entry; - lockdep_assert_held(&shrinker_rwsem); + lockdep_assert_held(&shrinker_mutex); shrinker_debugfs_name_free(shrinker); @@ -279,14 +279,14 @@ static int __init shrinker_debugfs_init(void) shrinker_debugfs_root = dentry; /* Create debugfs entries for shrinkers registered at boot */ - down_write(&shrinker_rwsem); + mutex_lock(&shrinker_mutex); list_for_each_entry(shrinker, &shrinker_list, list) if (!shrinker->debugfs_entry) { ret = shrinker_debugfs_add(shrinker); if (ret) break; } - up_write(&shrinker_rwsem); + mutex_unlock(&shrinker_mutex); return ret; }