From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0F842C5AE59 for ; Tue, 3 Jun 2025 13:24:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.sourceforge.net; s=beta; h=Content-Transfer-Encoding:Content-Type:Cc: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: Subject:In-Reply-To:MIME-Version:References:Message-ID:To:From:Date:Sender: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=YhpPmT8fF4gpgNzRgVgGBuZIFJgZ9pHsnFaOplvr7kU=; b=baLhaB+joszbOVt/yEqr9Z9n1v IWAkKcAQr9uDGU1dbYpAx9O9xzPCk8tYCt/2luxvDW5/+Il/mep+5GAOXhzzBXi/bZYobzkwWz+0D I4TgxM/CHPlBI4pUoEa/n/Gs5/pQHB3sSSwiAzv6unqCmIdIp/Rabw7XW7qu4wHmCrAU=; Received: from [127.0.0.1] (helo=sfs-ml-3.v29.lw.sourceforge.com) by sfs-ml-3.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1uMRdO-0005Ae-Mr; Tue, 03 Jun 2025 13:24:54 +0000 Received: from [172.30.29.66] (helo=mx.sourceforge.net) by sfs-ml-3.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1uMRdL-0005AX-8e for linux-f2fs-devel@lists.sourceforge.net; Tue, 03 Jun 2025 13:24:51 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=In-Reply-To:Content-Type:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=QfdJcMtitqVv2K9sFm4dcEYmSiJwmxzfWqAeWpKi4OE=; b=hkWaEC8uZkvx9/RcLp5YpV9oru qtQjbPJxPsta0KHeIkyZcK5U5tzzecpPrbxRgah2jfSahAXa1BrJ6akLhHw4nAQmKBv2WJaJAq1kD NVrd1Mla6hMjdYyDeLzkmzqAy6k6L9xeQXxVaECfsqTbW4yS70qi81SJ9Fcz8eUOr8fE=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To :From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=QfdJcMtitqVv2K9sFm4dcEYmSiJwmxzfWqAeWpKi4OE=; b=dAj7s1UXYVVOGBdB/43xoiJqK7 uvB6y2DuTjilm8OhiIdmZ8dfDZ2TMDGzN+O3PpDPxGoXjim3x6QK5F+zdLsjmf870gG0IX3lpaRqa tbV+2bAPixiRwEUeZHJ4V7/XulInSmuHkm/pPDzV6wwQTlU/iw9KmleZsNN5iFOINHpg=; Received: from verein.lst.de ([213.95.11.211]) by sfi-mx-2.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.95) id 1uMRdK-0002GL-7K for linux-f2fs-devel@lists.sourceforge.net; Tue, 03 Jun 2025 13:24:51 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id D45DF68D0F; Tue, 3 Jun 2025 15:24:34 +0200 (CEST) Date: Tue, 3 Jun 2025 15:24:34 +0200 From: Christoph Hellwig To: Anuj Gupta/Anuj Gupta Message-ID: <20250603132434.GA10865@lst.de> References: <20250529111504.89912-1-kundan.kumar@samsung.com> <20250602141904.GA21996@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-Headers-End: 1uMRdK-0002GL-7K Subject: Re: [f2fs-dev] [PATCH 00/13] Parallelizing filesystem writeback X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: ritesh.list@gmail.com, anuj1072538@gmail.com, jack@suse.cz, djwong@kernel.org, amir73il@gmail.com, david@fromorbit.com, gfs2@lists.linux.dev, linux-mm@kvack.org, clm@meta.com, Christoph Hellwig , dave@stgolabs.net, agruenba@redhat.com, miklos@szeredi.hu, Kundan Kumar , willy@infradead.org, p.raghav@samsung.com, linux-nfs@vger.kernel.org, da.gomez@samsung.com, viro@zeniv.linux.org.uk, kundanthebest@gmail.com, jaegeuk@kernel.org, axboe@kernel.dk, brauner@kernel.org, linux-f2fs-devel@lists.sourceforge.net, mcgrof@kernel.org, anna@kernel.org, gost.dev@samsung.com, linux-fsdevel@vger.kernel.org, akpm@linux-foundation.org, trondmy@kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net On Tue, Jun 03, 2025 at 02:46:20PM +0530, Anuj Gupta/Anuj Gupta wrote: > On 6/2/2025 7:49 PM, Christoph Hellwig wrote: > > On Thu, May 29, 2025 at 04:44:51PM +0530, Kundan Kumar wrote: > > Well, the proper thing would be to figure out a good default and not > > just keep things as-is, no? > > We observed that some filesystems, such as Btrfs, don't benefit from > this infra due to their distinct writeback architecture. To preserve > current behavior and avoid unintended changes for such filesystems, > we have kept nr_wb_ctx=1 as the default. Filesystems that can take > advantage of parallel writeback (xfs, ext4) can opt-in via a mount > option. Also we wanted to reduce risk during initial integration and > hence kept it as opt-in. A mount option is about the worst possible interface for behavior that depends on file system implementation and possibly hardware chacteristics. This needs to be set by the file systems, possibly using generic helpers using hardware information. > Used PMEM of 6G battery/capacitor backed DRAM, or optane? > > and NVMe SSD of 3.84 TB Consumer drive, enterprise drive? > For xfs used this command: > xfs_io -c "stat" /mnt/testfile > And for ext4 used this: > filefrag /mnt/testfile filefrag merges contiguous extents, and only counts up for discontiguous mappings, while fsxattr.nextents counts all extent even if they are contiguous. So you probably want to use filefrag for both cases. _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel