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 F39CEC38A2D for ; Tue, 25 Oct 2022 16:02:07 +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=C6SJicJ9BucqOu96ENJp75afWx02l2PtqBTutuq4cKg=; b=iSKOT6lQ69uAfMOBiI5+1zkWRX zYqbHIsgxzYHdSMfzRBjm1KCjunzAmqRQnlLafImMh2x7+PHyuW3Vcn/SmSTmQ84CRCYhmczyWXcO AtFapPHTvi+mfMUw09X2gIuS2UFRm7PSgHkqgEMsOD3qprntKU2yR9JcT65svUyOWzTAlaqqOERJI YQ62tBdqzkslVfllDhPX3fNw4xioNrEmWEbaGZLLWfqU2ugC66B+/F/+uXicsud5ijNc42uwhVQqh qoJa6kt2RLn+dRyJcskhpM625/WymBRQZdJuJVGW/lDooy7qrtImNsgoYgDjLvwyiDAPWhlTBsTH4 MbI7+IEw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1onMNR-006DFL-Sg; Tue, 25 Oct 2022 16:02:05 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1onMNP-006DEA-41 for linux-nvme@lists.infradead.org; Tue, 25 Oct 2022 16:02:04 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 46BD368C4E; Tue, 25 Oct 2022 18:02:00 +0200 (CEST) Date: Tue, 25 Oct 2022 18:01:59 +0200 From: Christoph Hellwig To: Aurelien Aptel Cc: netdev@vger.kernel.org, davem@davemloft.net, kuba@kernel.org, edumazet@google.com, pabeni@redhat.com, saeedm@nvidia.com, tariqt@nvidia.com, leon@kernel.org, linux-nvme@lists.infradead.org, sagi@grimberg.me, hch@lst.de, kbusch@kernel.org, axboe@fb.com, chaitanyak@nvidia.com, smalin@nvidia.com, ogerlitz@nvidia.com, yorayz@nvidia.com, borisp@nvidia.com, aurelien.aptel@gmail.com, malin1024@gmail.com Subject: Re: [PATCH v7 02/23] iov_iter: DDP copy to iter/pages Message-ID: <20221025160159.GB26372@lst.de> References: <20221025135958.6242-1-aaptel@nvidia.com> <20221025135958.6242-3-aaptel@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221025135958.6242-3-aaptel@nvidia.com> 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-20221025_090203_329269_5E8A8342 X-CRM114-Status: GOOD ( 11.05 ) 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 I don't think this is a good subject line. What the patch does is to skip the memcpy, so something about that in the subject. You can then explain the commit log why that is done. And given that the behavior isn't all that obvious I think a big fat comment in the code would be very helpful in this case as well.