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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7A0E7C35FFF for ; Thu, 20 Mar 2025 14:54:59 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6ED8F280002; Thu, 20 Mar 2025 10:54:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 69D29280001; Thu, 20 Mar 2025 10:54:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 58D21280002; Thu, 20 Mar 2025 10:54:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 3D39D280001 for ; Thu, 20 Mar 2025 10:54:56 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 574A716165E for ; Thu, 20 Mar 2025 14:54:58 +0000 (UTC) X-FDA: 83242226676.13.695B38C Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf10.hostedemail.com (Postfix) with ESMTP id 9AD68C0011 for ; Thu, 20 Mar 2025 14:54:56 +0000 (UTC) Authentication-Results: imf10.hostedemail.com; dkim=none; spf=pass (imf10.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1742482496; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QJ2Ui0lp0RUXdKTddyvhpn3pbA8Kt/uaDTnkJgJzxxQ=; b=o8gn5/acEx8HnGRJaPuTZdCiBifd01D9A7uqs0LW+2d4RILlVduJUyMt2BiNw/WQdTqTCI 1hnL092+9HMHjSEscJjgmBqhXp1NCBgNHrt0j0g1ldjOqNGZamTzqLvEwieQ5xdy+KUj+Y u1c/uSDbch2MhJ1zjaGtaFyHcwpv/SY= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1742482496; a=rsa-sha256; cv=none; b=UwaxvvtLpoyD3CFnePpoLayheBWzYDRsC4YM2WBL7bvsZ0jN9AVXSP3O39/8Eu++3j6rMt pDKP1IchGGciu58CqSi6mdqLn/n7gFd2Fuu9IKo1TBofjXeax0aXFLG306i5tvdQ4jYkQJ c78197XUoMRREHRzB1gbwWV3xq/5JEg= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=none; spf=pass (imf10.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de; dmarc=none Received: by verein.lst.de (Postfix, from userid 2407) id 2AD9868BFE; Thu, 20 Mar 2025 15:54:50 +0100 (CET) Date: Thu, 20 Mar 2025 15:54:49 +0100 From: Christoph Hellwig To: Daniel Gomez Cc: Luis Chamberlain , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org, lsf-pc@lists.linux-foundation.org, david@fromorbit.com, leon@kernel.org, hch@lst.de, kbusch@kernel.org, sagi@grimberg.me, axboe@kernel.dk, joro@8bytes.org, brauner@kernel.org, hare@suse.de, willy@infradead.org, djwong@kernel.org, john.g.garry@oracle.com, ritesh.list@gmail.com, p.raghav@samsung.com, gost.dev@samsung.com, da.gomez@samsung.com Subject: Re: [LSF/MM/BPF TOPIC] breaking the 512 KiB IO boundary on x86_64 Message-ID: <20250320145449.GA14191@lst.de> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-Rspam-User: X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 9AD68C0011 X-Stat-Signature: nus385dq3bukpxryez5sh9k6f7yposfc X-HE-Tag: 1742482496-311432 X-HE-Meta: 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Mar 20, 2025 at 02:47:22PM +0100, Daniel Gomez wrote: > On Thu, Mar 20, 2025 at 04:41:11AM +0100, Luis Chamberlain wrote: > > We've been constrained to a max single 512 KiB IO for a while now on x86_64. > > This is due to the number of DMA segments and the segment size. With LBS the > > segments can be much bigger without using huge pages, and so on a 64 KiB > > block size filesystem you can now see 2 MiB IOs when using buffered IO. > > Actually up to 8 MiB I/O with 64k filesystem block size with buffered I/O > as we can describe up to 128 segments at 64k size. Block layer segments are in no way limited to the logical block size.