From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794316771; b=lkpi9pyJz1NzfFnfETPUH+pn+7Zg0a6pJAH6fCgUO3QLspximCND32rYdQWnCb02duA0 ElT3abpGsDQiuUMkOt6wsmVu17oKA1RsLIHqxHE8VOTWq+QG1ot2d/5jZQVlMQkMeDCxF gUx+K5d39sZwCza65gY0Da3F5G+/2siridUAXHaHQsBFdmACpTQFr0o+u5q/qv1lgmwEr ck2ktxfthAcGQKiwgyLLG4ZU1JqK3uT+dq67du0H7E71qRJ603aSU5P9Y6ZqHm8BUteH3 YE2pALUa2ezmFwO/WCYWtNprDJ8I7gUo9tS5JEjtZ9TMC8Lt0GqMLb/2ZZTxUOetlsQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794316771; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=1tJZJF/ZsCPtMo8he9iLF18ZSbR5KYRunu33upum5ac=; b=o5Acpii1VTs4dqBD44YXg/mG3A8cHYwRp+Pwnzu9Gv0Xqqm07mRg+IouORXmFvM4D1tB 5eDE7JVp7/7B3Mdv1J4JVCowOtojwhTB55y4EyYAQ1Cf/XWIFXJCG9anezN3JOp/9fToE B/o4YgIpWBNCReNZivUAPFbmSY+DkoLH5UsMzTujAoEmOwqtggn/4H/VpAKpME720b1IQ fTbTtM7Z4HEGWVX3YdkuKSeWTPgzedMhTJEIutyf2woPIHvfDvg2JMIu2ovts1Z8oZW25 yAIMbCaDorZxBxaBvsdihM5GFwkpb4OUHCT2F2rt/S21OCJGD7bXypPB4mMRzVFj35g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Z6BSUIZl; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 456A0606A7CF for ; Tue, 10 Nov 2026 13:19:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Z6BSUIZl Received: by smtp.kernel.org (Postfix) with ESMTPSA id 784121F0089F; Tue, 10 Nov 2026 13:19:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794316771; bh=1tJZJF/ZsCPtMo8he9iLF18ZSbR5KYRunu33upum5ac=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Z6BSUIZle7xmCpSUtQPsD5JR+9ZLHJYyTG3/+c8LnJjLfhyY8/mPVQvyFgQm38SPF 8afbS5kqv9npiHShiuOqxspYJe4emHC/JNcrpRHEv09Gbv7FkaVIF6pi3iDm+4BSiC m/xV9obLkAI3kEsNP+26GQ7M5Cif7uD7A4ff4imUG6jWmivvDmY4+zh8P7TvykYIuI YjA/lFfk6mpfs4qe8CCcp03sBsnvxJdKC1bszHYgpSHhfj6CgsJ7ON0S6mTHX1WNOo B58bxypaSMhMSrM+lTKLMq1qHZpYWwZ7RrEJXCNU3zsnTNHSEdkVja8gmwJwxvtFAK M7o9z4YmzFWVw== From: Sasha Levin To: stable@vger.kernel.org Cc: Breno Leitao , "Paul E. McKenney" , "Christian Brauner (Amutable)" , Sasha Levin Subject: [PATCH 6.1.y] dcache: report a Tasks-RCU quiescent state in dentry_kill() Date: Tue, 10 Nov 2026 08:19:28 -0500 Message-ID: <20261110131912.1715750-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261107054301-failed-6.1-a647a53bc89a@kernel.org> References: <20261107054301-failed-6.1-a647a53bc89a@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Breno Leitao [ Upstream commit a647a53bc89a046bee4a12a0a5627f2dfaaef807 ] I am constantly seeing the following warning on Meta's fleet: INFO: rcu_tasks detected stalls on tasks: native_queued_spin_lock_slowpath locked_inode_to_wb_and_lock_list inode_io_list_del evict __dentry_kill shrink_dentry_list shrink_dcache_tree d_invalidate btrfs_delete_subvolume btrfs_ioctl_snap_destroy btrfs_ioctl do_syscall_64 dentry_kill() is the common funnel for dentry teardown: dput(), shrink_dentry_list() and shrink_dcache_tree() all reach it, once per dentry, and its cond_resched() is the only reschedule point on that path. cond_resched() is not an RCU-tasks quiescent state. Use cond_resched_tasks_rcu_qs() so the teardown reports an RCU-tasks quiescent state as it proceeds. Fixes: 9c5f1d30199d ("dcache: move cond_resched() into the end of __dentry_kill()") Cc: stable@vger.kernel.org Signed-off-by: Breno Leitao Link: https://patch.msgid.link/20260918-dcache-task-rcu-qa-v1-1-963ec83e6d0b@debian.org Reviewed-by: Paul E. McKenney Signed-off-by: Christian Brauner (Amutable) [ sashal: applied the change in __dentry_kill() instead of dentry_kill() ] Signed-off-by: Sasha Levin --- fs/dcache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/dcache.c b/fs/dcache.c index 205552e31b200..a03646aff093d 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -623,7 +623,7 @@ static void __dentry_kill(struct dentry *dentry) spin_unlock(&dentry->d_lock); if (likely(can_free)) dentry_free(dentry); - cond_resched(); + cond_resched_tasks_rcu_qs(); } static struct dentry *__lock_parent(struct dentry *dentry) -- 2.53.0