From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out28-86.mail.aliyun.com (out28-86.mail.aliyun.com [115.124.28.86]) (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 36BB010E3 for ; Wed, 24 Jan 2024 00:35:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.28.86 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706056514; cv=none; b=ctOIlAz7ryRK7Mzo2c6lZKIyZGkXSaePM8/6cYNYh4iDq0xxPR2VL+Bq7DIsDQUvTM/4TCj2cSsiFTpPtVSdxu/OAu/errewG/R7xM4MMlWJW2wAtqgcxEDFjqSp1W4mFvjra2lK91wmXsSEOBk0i8GU98gC+MtjJjhGaGw9ojM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706056514; c=relaxed/simple; bh=Vi6VImysOkiaMhfKEC3LdSmLIVGOPrh3PlDyUDPWD0s=; h=Date:From:To:Subject:Cc:In-Reply-To:References:Message-Id: MIME-Version:Content-Type; b=iJtSfAcSqH2NzJIdbuh+CLP5g9cNhn2N+OQOi+SuXaSqyZVdtpy2S7k4mlEzzWiva5dy+s3czAoq+1kYkAT0mAWELfgQ+FbKfwocst5Z6LmuNrl3pZD9QXk3izmwcTWllyFPCjIT/jtPQNjddzh9lmP0tbeASUWLA+Sq+9ZmD9o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=e16-tech.com; spf=pass smtp.mailfrom=e16-tech.com; arc=none smtp.client-ip=115.124.28.86 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=e16-tech.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=e16-tech.com X-Alimail-AntiSpam:AC=CONTINUE;BC=0.3290177|-1;CH=green;DM=|CONTINUE|false|;DS=CONTINUE|ham_system_inform|0.035754-0.00378335-0.960463;FP=0|0|0|0|0|-1|-1|-1;HT=ay29a033018047204;MF=wangyugui@e16-tech.com;NM=1;PH=DS;RN=2;RT=2;SR=0;TI=SMTPD_---.WDbChXF_1706055571; Received: from 192.168.2.112(mailfrom:wangyugui@e16-tech.com fp:SMTPD_---.WDbChXF_1706055571) by smtp.aliyun-inc.com; Wed, 24 Jan 2024 08:19:32 +0800 Date: Wed, 24 Jan 2024 08:19:32 +0800 From: Wang Yugui To: Naohiro Aota Subject: Re: [PATCH 0/2] btrfs: disable inline checksum for multi-dev striped FS Cc: linux-btrfs@vger.kernel.org In-Reply-To: References: Message-Id: <20240124081931.1DDE.409509F4@e16-tech.com> Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.81.05 [en] Hi, > There was a report of write performance regression on 6.5-rc4 on RAID0 > (4 devices) btrfs [1]. Then, I reported that BTRFS_FS_CSUM_IMPL_FAST > and doing the checksum inline can be bad for performance on RAID0 > setup [2]. > > [1] https://lore.kernel.org/linux-btrfs/20230731152223.4EFB.409509F4@e16-tech.com/ > [2] https://lore.kernel.org/linux-btrfs/p3vo3g7pqn664mhmdhlotu5dzcna6vjtcoc2hb2lsgo2fwct7k@xzaxclba5tae/ > > While inlining the fast checksum is good for single (or two) device, > but it is not fast enough for multi-device striped writing. > > So, this series first introduces fs_devices->inline_csum_mode and its > sysfs interface to tweak the inline csum behavior (auto/on/off). Then, > it disables inline checksum when it find a block group striped writing > into multiple devices. We have struct btrfs_inode | sync_writers in kernel 6.1.y, but dropped in recent kernel. Is btrfs_inode | sync_writers not implemented very well? Best Regards Wang Yugui (wangyugui@e16-tech.com) 2024/01/24