From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 26AF4330B01; Wed, 27 May 2026 15:59:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779897579; cv=none; b=PRhA96na2bJGnC9RtFO4d+I4+FUfR7uqGlLuHD7UBdPnGhFC5Gv14bH3R0rbWYLEpki2lM3jUnWnUIfJML85iwcvJhebZUnwrqSRl7GAfp+VJyC41Ggq3Ty2fnQYMk6GdcfwPaycW1QIp0bHZqy8ofzHsMMmffvnoGk5OWmJw4U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779897579; c=relaxed/simple; bh=93hGzeUNZXSmgPP5rRVCOqylEsp/Noq5x/ntYlDk91Y=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Xnxuog08Msp3H4b6vU5bK368v3oysKUYP66PK0wLnn4YFyM9NfdIrQdvClSghZO0+fdMCpWxIS82jDMSOs3KJB9Ky4doC7nW1BlaaLhTumXxfVzpr8lbxY9QeoHep40ZbTgSivpprJVK7oXxs12hG2MOZR8C/RX8kcXKXzmnzsI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RYqc0BD/; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="RYqc0BD/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6866E1F000E9; Wed, 27 May 2026 15:59:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779897577; bh=ky5x6VV8bGsiRibL4Mbeireh2/3HHtZ2G1qotL6tKkE=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=RYqc0BD/c9Rk6VG80/Ku4juq+/5NhEA9655oRwH1Wmuep9DRWmqdGxTBZaGOAbx4c tAWp51YEvq1+8lth6riLToTePL3f5jhd0A9B+eajyaSW8fHPYWYjSs9849zYuwPqKi SkmrQ1Sj73F1X2nwofk44uZKbCtcjtNxLKSdqk50qPKRabEVz9ZGdCeRb9P/jUX7Gp ROw64V0uXEJeCATrY80FENgdTyVVifxFzRe5FtVsGqwU6po13npcbonInSgIoCh8L0 uwTj53KmkgZ1MFEdp8hsLXFebtZo4DHZROQbE1pFiS8JcRGFroxsy56nkfPhdv80xj RmK8vLj9DyWvQ== Date: Wed, 27 May 2026 15:59:35 +0000 From: Jaegeuk Kim To: Christoph Hellwig Cc: Bart Van Assche , Theodore Tso , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Matthew Wilcox , linux-f2fs-devel@lists.sourceforge.net, linux-mm@kvack.org, Akilesh Kailash , linux-fsdevel@vger.kernel.org, Christian Brauner Subject: Re: [f2fs-dev] [PATCH v2] f2fs: another way to set large folio by remembering inode number Message-ID: References: <20260521155748.GA79343@macsyma-wired.lan> <20260522141115.GA8258@macsyma-wired.lan> <20260522224108.GA18663@macsyma-wired.lan> Precedence: bulk X-Mailing-List: linux-fsdevel@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: On 05/26, Christoph Hellwig wrote: > On Tue, May 26, 2026 at 09:14:52AM -0700, Bart Van Assche wrote: > > On 5/26/26 6:42 AM, Theodore Tso wrote: > > > It seems... surprising that the additional I/O operations are actually > > > throttloing UFS device bandwidth by 2x (4GB/s vs 2GB/s). Have you dug > > > into why this is happening, and whether there is anything that can be > > > optimized below the file system? > > The layers below the filesystem (block, SCSI, UFS) is what I'm > > responsible for in the Pixel team and I can assure you that these are > > highly optimized. > > > > Since the transfer size used in Jaegeuk's tests is much larger than 4 > > KiB, how many CPU cycles are used per IO by the layers below the > > filesystem is not limiting the transfer bandwidth. > > I'm honestly not sure what discussion we have here. Larger I/O is > pretty much always more efficient. If you submit smaller I/O you > need more merging to build it back up larger, and more I/Os. F2FS merges bios before submit_bio, regardless of small or large folios, since the block addresses are consecutive. So, I think IO subsystem was working in full speed. > > Which is exaxtly why we need large folio support everywhere, as it > makes a huge difference in I/O performance. > > > > _______________________________________________ > Linux-f2fs-devel mailing list > Linux-f2fs-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel 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 9B823CD4F54 for ; Wed, 27 May 2026 16:00:12 +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: Reply-To:From:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Subject:In-Reply-To:MIME-Version:References: Message-ID:To:Date:Sender:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=eolY87L7sxZzYADH1qBvTdDKCBAk0vD+rxM0KW5Mif8=; b=Ky+rGzPCDEZVCpvhoanajaOFxe InYK6DGhSfeFSKiNC2XJev1QHZzNSyQ+FsQNy1RlFU+hfet+o2jNlxNFXNkL5D24t/M4efuyehGdG Vq4J+3cdughgJZozHYQ1tNyfD8fAP6TGjYT5QvpuRMhJQCMbJJlNKtHNNbKuvrbzIJ6g=; Received: from [127.0.0.1] (helo=sfs-ml-2.v29.lw.sourceforge.com) by sfs-ml-2.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1wSGfu-0004Xc-T4; Wed, 27 May 2026 16:00:07 +0000 Received: from [172.30.29.66] (helo=mx.sourceforge.net) by sfs-ml-2.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1wSGfd-0004Vj-Dh for linux-f2fs-devel@lists.sourceforge.net; Wed, 27 May 2026 15:59:50 +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=ky5x6VV8bGsiRibL4Mbeireh2/3HHtZ2G1qotL6tKkE=; b=Pc/FKZ2hO4FtujTnTtKg59tFu6 8LzbMxEqI4JTtEp6ejdZfpwcLQVnjMDPAQ4gKSZLy3pqgEsWbsVSRyqC5RtqO9cIfjXApI1SCMbJC oszYci1GWeQcFPQIfUVJLvbzHuqTkT2vWIkzqYQSYpcIlB7zNK6M4hStUET1Nz75OkQQ=; 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=ky5x6VV8bGsiRibL4Mbeireh2/3HHtZ2G1qotL6tKkE=; b=CFlFYctT9Bmc74EhmR3uGoRLip 6CPjdOgUeZTi6Ae+oiVyRg/1X5h8jD6S0AhKXLO6WwR/IvbE0ELIIn1p5hVnjQsYMYdN34O1rQu0f d7QV1gf9tUhZkYBn1JoNNHEAiSYXbU9cBKvwAyqZuYECIfsGfq1Tl0mIGo/EyX/iSqIc=; Received: from tor.source.kernel.org ([172.105.4.254]) by sfi-mx-2.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.95) id 1wSGfc-0005e3-9S for linux-f2fs-devel@lists.sourceforge.net; Wed, 27 May 2026 15:59:50 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 210486021C; Wed, 27 May 2026 15:59:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6866E1F000E9; Wed, 27 May 2026 15:59:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779897577; bh=ky5x6VV8bGsiRibL4Mbeireh2/3HHtZ2G1qotL6tKkE=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=RYqc0BD/c9Rk6VG80/Ku4juq+/5NhEA9655oRwH1Wmuep9DRWmqdGxTBZaGOAbx4c tAWp51YEvq1+8lth6riLToTePL3f5jhd0A9B+eajyaSW8fHPYWYjSs9849zYuwPqKi SkmrQ1Sj73F1X2nwofk44uZKbCtcjtNxLKSdqk50qPKRabEVz9ZGdCeRb9P/jUX7Gp ROw64V0uXEJeCATrY80FENgdTyVVifxFzRe5FtVsGqwU6po13npcbonInSgIoCh8L0 uwTj53KmkgZ1MFEdp8hsLXFebtZo4DHZROQbE1pFiS8JcRGFroxsy56nkfPhdv80xj RmK8vLj9DyWvQ== Date: Wed, 27 May 2026 15:59:35 +0000 To: Christoph Hellwig Message-ID: References: <20260521155748.GA79343@macsyma-wired.lan> <20260522141115.GA8258@macsyma-wired.lan> <20260522224108.GA18663@macsyma-wired.lan> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Headers-End: 1wSGfc-0005e3-9S Subject: Re: [f2fs-dev] [PATCH v2] f2fs: another way to set large folio by remembering inode number 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: , From: Jaegeuk Kim via Linux-f2fs-devel Reply-To: Jaegeuk Kim Cc: Theodore Tso , Bart Van Assche , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Matthew Wilcox , linux-f2fs-devel@lists.sourceforge.net, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Akilesh Kailash , Christian Brauner Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net On 05/26, Christoph Hellwig wrote: > On Tue, May 26, 2026 at 09:14:52AM -0700, Bart Van Assche wrote: > > On 5/26/26 6:42 AM, Theodore Tso wrote: > > > It seems... surprising that the additional I/O operations are actually > > > throttloing UFS device bandwidth by 2x (4GB/s vs 2GB/s). Have you dug > > > into why this is happening, and whether there is anything that can be > > > optimized below the file system? > > The layers below the filesystem (block, SCSI, UFS) is what I'm > > responsible for in the Pixel team and I can assure you that these are > > highly optimized. > > > > Since the transfer size used in Jaegeuk's tests is much larger than 4 > > KiB, how many CPU cycles are used per IO by the layers below the > > filesystem is not limiting the transfer bandwidth. > > I'm honestly not sure what discussion we have here. Larger I/O is > pretty much always more efficient. If you submit smaller I/O you > need more merging to build it back up larger, and more I/Os. F2FS merges bios before submit_bio, regardless of small or large folios, since the block addresses are consecutive. So, I think IO subsystem was working in full speed. > > Which is exaxtly why we need large folio support everywhere, as it > makes a huge difference in I/O performance. > > > > _______________________________________________ > Linux-f2fs-devel mailing list > Linux-f2fs-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel