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 4C9CE27FD62 for ; Wed, 24 Sep 2025 07:59:02 +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=1758700744; cv=none; b=QIzxBnlO3nJTbk4cnvAgRPjr+rgWgezThpYloguX0Dj5xNfOYthdokBrLF/DpQIqa5GBqTa4M0X5rYlKvCky/+UxZWlwEAYDOoChEJwCRy4uN4ItsvkiPSCqgtvFJMtT02LSF2hBcYX+NK8scrfh36HZXbJMTW2YMg0XYjIt328= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758700744; c=relaxed/simple; bh=ebGmTogsoiIyNshxuoFonK4bfNHzVNAVFWeWw4P6UXs=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=O3d4PSHfPR/CruPBYRypyB/KiAB6qNYaKiOLnrCeSZWghqYobUoCzBTahtdzhumqllSLwjth9e7euodPuHZZJO60IgzbxbsTIpwLidZZLy8YmvoB099A6NcJGsyzrnPNkWN/vQZAYC16JVrHK+/1nql59jjiwMkmBCdPT/LcQmA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LPQ8XGB7; 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="LPQ8XGB7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9BB21C4CEE7; Wed, 24 Sep 2025 07:59:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758700742; bh=ebGmTogsoiIyNshxuoFonK4bfNHzVNAVFWeWw4P6UXs=; h=Date:Cc:Subject:To:References:From:In-Reply-To:From; b=LPQ8XGB7T0yQzn+lDE3chKsbahiJJmvuFHgieF8/se7iVnfHY32swQwMLjw6jDL8X njuN9dNeSNJoqDHMS11aZ0VFj+J2NO8wMdkjFepFgc7FthNiP+HkpNQv13ANedFr4f NlkMU1Zb3TlocBBQk+l7Gs6ptIr4I45hBHRY3N/wWrEojhM/mm7V4abUGain9Vnf7H 4mckGpU2v5XwHat794wQH3jhNB1vQv8SxjoSONKaJMM8hf0/cZ5QNZKG6QGev/ytQc LvTpK8xkpns7fEdTIUt+hUn0nw4yFwFfmgE1yueM7lJSpunxfOncjpecexy9BA9JW1 OSTbjZ3xT6uzQ== Message-ID: <6529ffee-d2ee-41ff-97d0-bf483fd0530a@kernel.org> Date: Wed, 24 Sep 2025 15:58:58 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: chao@kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Sungjong Seo , Sunmin Jeong Subject: Re: [PATCH v4] f2fs: readahead node blocks in F2FS_GET_BLOCK_PRECACHE mode To: Yunji Kang , jaegeuk@kernel.org References: <20250924074358.253759-1-yunji0.kang@samsung.com> Content-Language: en-US From: Chao Yu In-Reply-To: <20250924074358.253759-1-yunji0.kang@samsung.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/24/25 15:43, Yunji Kang wrote: > In f2fs_precache_extents(), For large files, It requires reading many > node blocks. Instead of reading each node block with synchronous I/O, > this patch applies readahead so that node blocks can be fetched in > advance. > > It reduces the overhead of repeated sync reads and improves efficiency > when precaching extents of large files. > > I created a file with the same largest extent and executed the test. > For this experiment, I set the file's largest extent with an offset of 0 > and a size of 1GB. I configured the remaining area with 100MB extents. > > 5GB test file: > dd if=/dev/urandom of=test1 bs=1m count=5120 > cp test1 test2 > fsync test1 > dd if=test1 of=test2 bs=1m skip=1024 seek=1024 count=100 conv=notrunc > dd if=test1 of=test2 bs=1m skip=1224 seek=1224 count=100 conv=notrunc > ... > dd if=test1 of=test2 bs=1m skip=5024 seek=5024 count=100 conv=notrunc > reboot > > I also created 10GB and 20GB files with large extents using the same > method. > > ioctl(F2FS_IOC_PRECACHE_EXTENTS) test results are as follows: > +-----------+---------+---------+-----------+ > | File size | Before | After | Reduction | > +-----------+---------+---------+-----------+ > | 5GB | 101.8ms | 37.0ms | 72.1% | > | 10GB | 222.9ms | 56.0ms | 74.9% | > | 20GB | 446.2ms | 116.4ms | 73.9% | > +-----------+---------+---------+-----------+ > Tested on a 256GB mobile device with an SM8750 chipset. > > Reviewed-by: Sungjong Seo > Reviewed-by: Sunmin Jeong > Signed-off-by: Yunji Kang Reviewed-by: Chao Yu Thanks,