From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C7B307FBCA; Mon, 18 Dec 2023 12:46:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eeRQg0ar" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7E0D0C433CA; Mon, 18 Dec 2023 12:46:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1702903573; bh=5iuF1epyv3mwZoNuBNFGVrhC4joDGIutvo34c+ZkDz4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eeRQg0arcHa7PVqFekDhyZPCNKJMz+5qqGKKTZ50amj4njt6kn/LuqCv3Qkg+cg4b 52YAcaFmf+ZlKMauS1aoArwFNDIZhGGkpu+Eeq1KIXjXuSgpU8r9f2c7t4c7vCnAqJ w5078ZF1M0gX9vx6Zn3t/xqkSGydEvege19ImG9QgP2IqbhgozktjX9m255JLuNQY9 oGlZtfslloP3q9KN4b/tawPjGoih0DOGl6L+s2hAMVvGCfA7E4/1Fa3pKBU42ii2AX Tsi5XUjskRXWMB81XGIAkh39L4GTMTvWti8zwax/vKjZs0rwCZH+++XglGXmpA758c +gOszO8ohS44w== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ye Bin , Jan Kara , Theodore Ts'o , Sasha Levin , jack@suse.com, linux-ext4@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 07/13] jbd2: fix soft lockup in journal_finish_inode_data_buffers() Date: Mon, 18 Dec 2023 07:45:40 -0500 Message-ID: <20231218124557.1380724-7-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231218124557.1380724-1-sashal@kernel.org> References: <20231218124557.1380724-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.143 Content-Transfer-Encoding: 8bit From: Ye Bin [ Upstream commit 6c02757c936063f0631b4e43fe156f8c8f1f351f ] There's issue when do io test: WARN: soft lockup - CPU#45 stuck for 11s! [jbd2/dm-2-8:4170] CPU: 45 PID: 4170 Comm: jbd2/dm-2-8 Kdump: loaded Tainted: G OE Call trace: dump_backtrace+0x0/0x1a0 show_stack+0x24/0x30 dump_stack+0xb0/0x100 watchdog_timer_fn+0x254/0x3f8 __hrtimer_run_queues+0x11c/0x380 hrtimer_interrupt+0xfc/0x2f8 arch_timer_handler_phys+0x38/0x58 handle_percpu_devid_irq+0x90/0x248 generic_handle_irq+0x3c/0x58 __handle_domain_irq+0x68/0xc0 gic_handle_irq+0x90/0x320 el1_irq+0xcc/0x180 queued_spin_lock_slowpath+0x1d8/0x320 jbd2_journal_commit_transaction+0x10f4/0x1c78 [jbd2] kjournald2+0xec/0x2f0 [jbd2] kthread+0x134/0x138 ret_from_fork+0x10/0x18 Analyzed informations from vmcore as follows: (1) There are about 5k+ jbd2_inode in 'commit_transaction->t_inode_list'; (2) Now is processing the 855th jbd2_inode; (3) JBD2 task has TIF_NEED_RESCHED flag; (4) There's no pags in address_space around the 855th jbd2_inode; (5) There are some process is doing drop caches; (6) Mounted with 'nodioread_nolock' option; (7) 128 CPUs; According to informations from vmcore we know 'journal->j_list_lock' spin lock competition is fierce. So journal_finish_inode_data_buffers() maybe process slowly. Theoretically, there is scheduling point in the filemap_fdatawait_range_keep_errors(). However, if inode's address_space has no pages which taged with PAGECACHE_TAG_WRITEBACK, will not call cond_resched(). So may lead to soft lockup. journal_finish_inode_data_buffers filemap_fdatawait_range_keep_errors __filemap_fdatawait_range while (index <= end) nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end, PAGECACHE_TAG_WRITEBACK); if (!nr_pages) break; --> If 'nr_pages' is equal zero will break, then will not call cond_resched() for (i = 0; i < nr_pages; i++) wait_on_page_writeback(page); cond_resched(); To solve above issue, add scheduling point in the journal_finish_inode_data_buffers(); Signed-off-by: Ye Bin Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20231211112544.3879780-1-yebin10@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin --- fs/jbd2/commit.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index e058ef1839377..f858d1152368a 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -300,6 +300,7 @@ static int journal_finish_inode_data_buffers(journal_t *journal, if (!ret) ret = err; } + cond_resched(); spin_lock(&journal->j_list_lock); jinode->i_flags &= ~JI_COMMIT_RUNNING; smp_mb(); -- 2.43.0