From patchwork Mon Sep 11 09:44:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qi Zheng X-Patchwork-Id: 13379701 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 75E40CA0EDE for ; Mon, 11 Sep 2023 20:53:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229461AbjIKUxb (ORCPT ); Mon, 11 Sep 2023 16:53:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45318 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236160AbjIKJv6 (ORCPT ); Mon, 11 Sep 2023 05:51:58 -0400 Received: from mail-pl1-x630.google.com (mail-pl1-x630.google.com [IPv6:2607:f8b0:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED44CE4E for ; Mon, 11 Sep 2023 02:51:53 -0700 (PDT) Received: by mail-pl1-x630.google.com with SMTP id d9443c01a7336-1bf11a7cf9fso7706865ad.1 for ; Mon, 11 Sep 2023 02:51:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1694425913; x=1695030713; darn=vger.kernel.org; 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=oLAG3LFr2H9IpWa0Q1CUXr98GG6fWERP+Y/K9cMxF58=; b=RvyF4pPKBy5hOAHnud4//9lFEclFjxmW5j3JQfPkPaYaOMsFxQKMu/UxmJy6OMi3L3 BPHS90rjo/y+fJR4oQcJLLXxnegjER8MQ9SUp3AoMyxNlZGd19xUSPuVNKUkl/O8r5KO p/dBHDDtkSqe4NAGtbDMzIR6jPPdMvwCI7pfWUX4/FV6PonfGVB+4MvIaK+hda/WfsnZ qHnwGtJjGtsZagqjLDfHppIiOMsEfJWBVeVDuCv3hROmy87gDA1aKjvePgTDAErDfkNe mu1ZdExuZMtTEDH3tdoN2B12n5DpbHFbAms9lc97RAG88IR62CVRMxoQy26Tm8VDwJm7 Cf6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1694425913; x=1695030713; 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=oLAG3LFr2H9IpWa0Q1CUXr98GG6fWERP+Y/K9cMxF58=; b=rRb6DLfGFDjnfxUQ1BMS+JuZZdlTNVrfmvMakqNQF1eebmN6/M12acQjQ/T5580bzh kWZy1J9Jph1/vb39cdxqlwdKMcCI4+F0JP8RELfPH/xjMy9GCOrpu1eInhncIyRW4Ac/ CTQC8SzoVZWPkP6pWBl+J8t/WbSyUSWxk26phOUixpDK+0htvni/0snwdf08yWjkNPCn TrZ61lL987ZMruzzLfXQgvTeizN6tnf2KZSNeK1W3Llplt8Y9Ltem06CKKjDmIz88eRW ijTIs2uxKgbRmCqyGXZyCJEHRa+VlR3dk/zoNP7baigI6Wgz8iRCMwKbqM3QOSS7/lS7 sDow== X-Gm-Message-State: AOJu0YyVzObH9RDuaC8krcxNhk+Pybmq82kT/4KZ4OYbjUok1VXPaEUz zy9B3WRPBpcItF8H3MsZ4SxyUA== X-Google-Smtp-Source: AGHT+IGwEyIZI7e/UGLTPntdnRUQTR+mAjNl7rxKGC9aX+dD26VCCxP8WJPLnCYFs0FvhQRvA39K8A== X-Received: by 2002:a17:902:f155:b0:1c3:a4f2:7c99 with SMTP id d21-20020a170902f15500b001c3a4f27c99mr5142339plb.4.1694425913461; Mon, 11 Sep 2023 02:51:53 -0700 (PDT) Received: from C02DW0BEMD6R.bytedance.net ([203.208.167.146]) by smtp.gmail.com with ESMTPSA id az7-20020a170902a58700b001bdc2fdcf7esm5988188plb.129.2023.09.11.02.51.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Sep 2023 02:51:53 -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 Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Qi Zheng Subject: [PATCH v6 45/45] mm: shrinker: convert shrinker_rwsem to mutex Date: Mon, 11 Sep 2023 17:44:44 +0800 Message-Id: <20230911094444.68966-46-zhengqi.arch@bytedance.com> X-Mailer: git-send-email 2.24.3 (Apple Git-128) In-Reply-To: <20230911094444.68966-1-zhengqi.arch@bytedance.com> References: <20230911094444.68966-1-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 Reviewed-by: Muchun Song --- 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 adadf6689611..816a22a5cad1 100644 --- a/fs/super.c +++ b/fs/super.c @@ -178,7 +178,7 @@ static void super_wake(struct super_block *sb, unsigned int flag) * 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 471c07d75c4a..2c44c3d7afe9 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 int expand_one_shrinker_info(struct mem_cgroup *memcg, int new_size, @@ -154,7 +154,7 @@ 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); @@ -217,7 +217,7 @@ 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; @@ -231,7 +231,7 @@ static int shrinker_memcg_alloc(struct shrinker *shrinker) shrinker->id = id; ret = 0; unlock: - up_write(&shrinker_rwsem); + mutex_unlock(&shrinker_mutex); return ret; } @@ -241,7 +241,7 @@ 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); } @@ -292,7 +292,7 @@ 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); @@ -305,7 +305,7 @@ 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) @@ -735,11 +735,11 @@ 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); /* @@ -779,7 +779,7 @@ void shrinker_free(struct shrinker *shrinker) wait_for_completion(&shrinker->done); } - down_write(&shrinker_rwsem); + mutex_lock(&shrinker_mutex); if (shrinker->flags & SHRINKER_REGISTERED) { /* * Now we can safely remove it from the shrinker_list and then @@ -794,7 +794,7 @@ 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 38452f539f40..c80fd124f605 100644 --- a/mm/shrinker_debug.c +++ b/mm/shrinker_debug.c @@ -9,7 +9,7 @@ #include "internal.h" /* 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); @@ -165,7 +165,7 @@ 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) @@ -222,7 +222,7 @@ 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; @@ -240,7 +240,7 @@ 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); @@ -253,7 +253,7 @@ 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); @@ -281,14 +281,14 @@ 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; }