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 3D7CF207E1D for ; Tue, 29 Jul 2025 15:07:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753801637; cv=none; b=HZWsPdtx/VyyR64sihRkl1rTJPX652n82f6NmRB8+FlE9tZwLMkinUzXee2pTmZzJc1Vzf4KJHCz2enOzwOkQEg3WEw2GAP6YALjKB1O0m+dZxKUmvnedoARz3lYOekSUrVF/KTAfCYRTVuPJIYVKTQaVGQV1hDtoHtcGx69C4g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753801637; c=relaxed/simple; bh=Ei4j61++xYai4BK5l+E6lE08w0YyBTZsWiZjNGGayh8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Zxuny+q0YvuO97n5DRwOXuGe3KPXq9xSoLPe/l2hIva6h5Y2AU9ATgH5vmFGbp6lWZ10rWQkvj70pQSIgU7ivxlW615XrnOaSu6X0Gsgh/86dI6paODRCP+00pobRr0AdqrBnSO13+FL5MwKQTFgGH5rQBuX+XXdJeEvqwzIB0U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bTvkfjvu; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="bTvkfjvu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 870E2C4CEEF; Tue, 29 Jul 2025 15:07:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753801634; bh=Ei4j61++xYai4BK5l+E6lE08w0YyBTZsWiZjNGGayh8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=bTvkfjvuOt5QmZsgVZ+bICfYaIzVvCjhGSn8i2tm85TnsqOxHiBHQi2MR8EcUznT3 CS8IQnRLsh++3pzI6RblJg7URscFMAAi8FTV1DG17RcYbGvURxKegnmBReglCfsRHq MYl4dxfFLz3KYKdKIZab2j/TwbaR65LMdpgEjXrZ577NTI3t7I/CSb+qZNIikVhSX/ Y3woxHSyi230GmgAv3Z3rosdhuEnGlOAIgriYBgM9AW+Vh0s4kvA9Ethmt8j+WPBzF OS/oR946RLUkZh4USq/4ZOGF2jr90KQajlaDnjRca976/dGV7nQOU8bRgfV5uQw1CL C5PgcrUdIq4Mg== Date: Tue, 29 Jul 2025 15:07:12 +0000 From: Jaegeuk Kim To: Chao Yu Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Jan Prusakowski Subject: Re: [PATCH] f2fs: dump more information when checkpoint was blocked for long time Message-ID: References: <20250729063326.435167-1-chao@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250729063326.435167-1-chao@kernel.org> On 07/29, Chao Yu wrote: > generic/299 w/ mode=lfs will cause long time latency, let's dump more > information once we hit case. > > CP merge: > - Queued : 0 > - Issued : 1 > - Total : 1 > - Cur time : 7565(ms) > - Peak time : 7565(ms) > > F2FS-fs (vdc): checkpoint was blocked for 7565 ms, affecting 1 tasks > CPU: 8 UID: 0 PID: 1614 Comm: f2fs_ckpt-253:3 Tainted: G O 6.16.0-rc3+ #406 PREEMPT(voluntary) > Tainted: [O]=OOT_MODULE > Call Trace: > dump_stack_lvl+0x6e/0xa0 > __checkpoint_and_complete_reqs+0x1a6/0x1d0 > issue_checkpoint_thread+0x4b/0x140 > kthread+0x10d/0x250 > ret_from_fork+0x164/0x190 > ret_from_fork_asm+0x1a/0x30 Can we add more information for debugging this? > > Cc: Jan Prusakowski > Signed-off-by: Chao Yu > --- > fs/f2fs/checkpoint.c | 9 ++++++++- > fs/f2fs/f2fs.h | 3 +++ > 2 files changed, 11 insertions(+), 1 deletion(-) > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c > index db3831f7f2f5..b0dcaa8dc40d 100644 > --- a/fs/f2fs/checkpoint.c > +++ b/fs/f2fs/checkpoint.c > @@ -1788,8 +1788,15 @@ static void __checkpoint_and_complete_reqs(struct f2fs_sb_info *sbi) > > spin_lock(&cprc->stat_lock); > cprc->cur_time = (unsigned int)div64_u64(sum_diff, count); > - if (cprc->peak_time < cprc->cur_time) > + if (cprc->peak_time < cprc->cur_time) { > cprc->peak_time = cprc->cur_time; > + > + if (unlikely(cprc->peak_time >= CP_LONG_LATENCY_THRESHOLD)) { > + f2fs_warn_ratelimited(sbi, "checkpoint was blocked for %u ms, affecting %llu tasks", > + cprc->peak_time, count); > + dump_stack(); > + } > + } > spin_unlock(&cprc->stat_lock); > } > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index 46d23c2c086c..3130ca6a4770 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -350,6 +350,9 @@ struct ckpt_req_control { > unsigned int peak_time; /* peak wait time in msec until now */ > }; > > +/* a time threshold that checkpoint was blocked for, unit: ms */ > +#define CP_LONG_LATENCY_THRESHOLD 5000 > + > /* for the bitmap indicate blocks to be discarded */ > struct discard_entry { > struct list_head list; /* list head */ > -- > 2.49.0