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 C68ACC7115C for ; Wed, 25 Jun 2025 08:45:53 +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:References:To:MIME-Version:Date: Message-ID:Sender:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=5HE29cG69hpyBCZE9XAkW9PY/RTwoqsgH1VQmqFnlFU=; b=DpfAogwaqeRGO3dHhsFmimzqE9 ZukWitvbUkYY8jTkSUIhC22B/V/jQ+AJOHZeZ8w8bKLm8F/bARfLgjpahvZTpjvlQD5JX5lPaPsDi OwxssSen2aKqrWmZ2KRkZnCDrzhLeX3FZIYJZ69EZrU8ojOz6E+A6ri2mjb+dXzNYWcs=; Received: from [127.0.0.1] (helo=sfs-ml-1.v29.lw.sourceforge.com) by sfs-ml-1.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1uULlQ-0006Fb-Fq; Wed, 25 Jun 2025 08:45:52 +0000 Received: from [172.30.29.66] (helo=mx.sourceforge.net) by sfs-ml-1.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1uULku-000665-W4 for linux-f2fs-devel@lists.sourceforge.net; Wed, 25 Jun 2025 08:45:21 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: From:References:To:Subject:Cc:MIME-Version:Date:Message-ID:Sender:Reply-To: 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=84Phs29/epKpEmckUvJq9KGTCxiRXjiAJrTj2AM31E4=; b=U3gGKh6CNJoWk6qNx016ncmjKp CSMRqAtwwOEOS47Z7jihcWUv9oXar68rxU+mKPNCZVAsWMyb+Z6ztZkgtrrQV3Wp8F2/ULwPRoXNM 3B27FvI0HBPDlRkfXJs43ybh0XFK8tZEjZr/hl75ZoOl7cc553MN+G2fRlUnNHXR542Q=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From:References:To: Subject:Cc:MIME-Version:Date:Message-ID:Sender:Reply-To: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=84Phs29/epKpEmckUvJq9KGTCxiRXjiAJrTj2AM31E4=; b=bRNx/JFlBg6IlL+73M72L/dEpO om8gCKTPB1FmABlivHEKsySVYy0gXI6xXtjiUyAtN6fUhUwkTQZqqZaVpVdLMQmecMAcTFfveWm2p kbN+9qF1hBroWA6XLIhbLluxM03Ew4ptAZoAxsXUrBVKCLaGcLpNDe5aHdv+Qa/qHnN8=; Received: from dfw.source.kernel.org ([139.178.84.217]) by sfi-mx-2.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.95) id 1uULku-0002kL-J0 for linux-f2fs-devel@lists.sourceforge.net; Wed, 25 Jun 2025 08:45:20 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id BDF315C4814; Wed, 25 Jun 2025 08:42:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1A723C4CEF1; Wed, 25 Jun 2025 08:45:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750841109; bh=akGozF2xMqa27fiz+s8c9GDxo0IXK8cpAQzDW569FOc=; h=Date:Cc:Subject:To:References:From:In-Reply-To:From; b=UV05VOy86DshskpVnUKFSo5zPC2fD51gmvaD+ny+NX99Uznqh9vIPrEFZQGhk1zqo SDXlr9GI/6AeoW0Soh+TiWalcd5+IZOekzqCPqTld4YwntXszVbyoHR50WgLfugdxP rrt1iE0GaK84E1jLonzwvMKr4i0iQzrzJFhOnHOa2+WVTEA1toDPItblcty/fhagWn 44yws5P6T1G7uGtbkayKhlFFAcPHK4Ito3kGhWAy0P3Y1chisnDvxWiUc3HbV7xlnZ rf0RwdgiPr+pNIH8CJV3fNaWSt/kozL3eFcCyO4ZCKb8yJCs6qS+4Vik4WVSXnW7XA 8/CpVxLN4A+zQ== Message-ID: Date: Wed, 25 Jun 2025 16:45:06 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Jianan Huang , linux-f2fs-devel@lists.sourceforge.net, jaegeuk@kernel.org References: <20250625064927.516586-1-huangjianan@xiaomi.com> Content-Language: en-US In-Reply-To: <20250625064927.516586-1-huangjianan@xiaomi.com> X-Headers-End: 1uULku-0002kL-J0 Subject: Re: [f2fs-dev] [PATCH v3] f2fs: avoid splitting bio when reading multiple pages 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: Chao Yu via Linux-f2fs-devel Reply-To: Chao Yu Cc: Sheng Yong , linux-kernel@vger.kernel.org, wanghui33@xiaomi.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net On 6/25/25 14:49, Jianan Huang wrote: > When fewer pages are read, nr_pages may be smaller than nr_cpages. Due > to the nr_vecs limit, the compressed pages will be split into multiple > bios and then merged at the block level. In this case, nr_cpages should > be used to pre-allocate bvecs. > To handle this case, align max_nr_pages to cluster_size, which should be > enough for all compressed pages. > > Signed-off-by: Jianan Huang > Signed-off-by: Sheng Yong > --- > Changes since v2: > - Initialize index only for compressed files. > Changes since v1: > - Use aligned nr_pages instead of nr_cpages to pre-allocate bvecs. > > fs/f2fs/data.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index 31e892842625..d071d9f6a811 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -2303,7 +2303,7 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret, > } > > if (!bio) { > - bio = f2fs_grab_read_bio(inode, blkaddr, nr_pages, > + bio = f2fs_grab_read_bio(inode, blkaddr, nr_pages - i, Jianan, Another case: read page #0,1,2,3 from block #1000,1001,1002, cluster_size=4. nr_pages=4 max_nr_pages=round_up(0+4,4)-round_down(0,4)=4 f2fs_mpage_readpages() calls f2fs_read_multi_pages() when nr_pages=1, at that time, max_nr_pages equals to 1 as well. f2fs_grab_read_bio(..., 1 - 0,...) allocate bio w/ 1 vec capacity, however, we need at least 3 vecs to merge all cpages, right? Thanks, > f2fs_ra_op_flags(rac), > folio->index, for_write); > if (IS_ERR(bio)) { > @@ -2376,6 +2376,14 @@ static int f2fs_mpage_readpages(struct inode *inode, > unsigned max_nr_pages = nr_pages; > int ret = 0; > > +#ifdef CONFIG_F2FS_FS_COMPRESSION > + if (f2fs_compressed_file(inode)) { > + index = rac ? readahead_index(rac) : folio->index; > + max_nr_pages = round_up(index + nr_pages, cc.cluster_size) - > + round_down(index, cc.cluster_size); > + } > +#endif > + > map.m_pblk = 0; > map.m_lblk = 0; > map.m_len = 0; > @@ -2385,7 +2393,7 @@ static int f2fs_mpage_readpages(struct inode *inode, > map.m_seg_type = NO_CHECK_TYPE; > map.m_may_create = false; > > - for (; nr_pages; nr_pages--) { > + for (; nr_pages; nr_pages--, max_nr_pages--) { > if (rac) { > folio = readahead_folio(rac); > prefetchw(&folio->flags); _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel