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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 B98BCC71155 for ; Mon, 16 Jun 2025 12:39:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=UVEPxsiQhZZo2RmjLpYW2xuH5PAVOY2IdylDRDa/i1Y=; b=SFFcAZtqxTvd/Yc80Wb3gPKZur khVXl8rwAF0bmnsrYaEbA21A5QzydwDoAT0BK7pHh9fc9imSIn2BOatl1ifkvFbC22i4IZhtDLjfJ qvnqD+zZR4YLJrhECMI6SFlmBK4nz02t6IHEUVkxLolXsWhcl7nnFzVpZ+myxnkUuih8FoOmOiKDv FELm3zqvAWjPX3ZkuqbPwXBQQkPoLLujXtkJX0hR3P3rSikiiZ5UYId8QbiflK/YaanHuhdl3LhYQ itjR9S05qPjFquceVecZuiYpqJKvu0h7pfhyllj7MH4cQ1t074PNAoQDuE55+VLpDNCuub1heuS1P WvlekjMg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uR97P-00000004OYB-0Ad1; Mon, 16 Jun 2025 12:39:19 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uR87K-00000004DXj-3RWa for linux-nvme@lists.infradead.org; Mon, 16 Jun 2025 11:35:12 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 99CB368D07; Mon, 16 Jun 2025 13:35:06 +0200 (CEST) Date: Mon, 16 Jun 2025 13:35:05 +0200 From: Christoph Hellwig To: Daniel Gomez Cc: Christoph Hellwig , Jens Axboe , Keith Busch , Sagi Grimberg , Chaitanya Kulkarni , Kanchan Joshi , Leon Romanovsky , Nitesh Shetty , Logan Gunthorpe , linux-block@vger.kernel.org, linux-nvme@lists.infradead.org Subject: Re: [PATCH 7/9] nvme-pci: convert the data mapping blk_rq_dma_map Message-ID: <20250616113505.GA22121@lst.de> References: <20250610050713.2046316-1-hch@lst.de> <20250610050713.2046316-8-hch@lst.de> <871b014b-e308-4f20-9701-5581beee91ed@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <871b014b-e308-4f20-9701-5581beee91ed@kernel.org> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250616_043510_996929_94B7840F X-CRM114-Status: GOOD ( 14.66 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Mon, Jun 16, 2025 at 09:49:47AM +0200, Daniel Gomez wrote: > > #define NVME_MAX_SEGS \ > > - min(NVME_CTRL_PAGE_SIZE / sizeof(struct nvme_sgl_desc), \ > > - (PAGE_SIZE / sizeof(struct scatterlist))) > > + (NVME_CTRL_PAGE_SIZE / sizeof(struct nvme_sgl_desc)) > > IIRC, I've seen in the commit history going from PAGE_SIZE to CC.MPS for > different cases in the driver. PRPs requires contiguous regions to be CC.MPS, > i.e use NVME_CTRL_PAGE_SIZE for PRP lists and entries. But I think that is not a > limit for SGLs. Can we use PAGE_SIZE here? Sure. Separate unrelated patch, though.