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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 670F9C2BA19 for ; Thu, 23 Apr 2020 06:10:33 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 44A7B214AF for ; Thu, 23 Apr 2020 06:10:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 44A7B214AF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D9CF46E148; Thu, 23 Apr 2020 06:10:29 +0000 (UTC) Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by gabe.freedesktop.org (Postfix) with ESMTPS id 75C8F6E135; Thu, 23 Apr 2020 06:10:28 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id B47E6227A81; Thu, 23 Apr 2020 08:10:23 +0200 (CEST) Date: Thu, 23 Apr 2020 08:10:23 +0200 From: Christoph Hellwig To: Jason Gunthorpe Message-ID: <20200423061023.GA9856@lst.de> References: <0-v1-4eb72686de3c+5062-hmm_no_flags_jgg@mellanox.com> <5-v1-4eb72686de3c+5062-hmm_no_flags_jgg@mellanox.com> <20200422060329.GD22366@lst.de> <20200422123911.GV26002@ziepe.ca> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200422123911.GV26002@ziepe.ca> User-Agent: Mutt/1.5.17 (2007-11-01) Subject: Re: [Intel-gfx] [PATCH hmm 5/5] mm/hmm: remove the customizable pfn format from hmm_range_fault X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "David \(ChunMing\) Zhou" , Ralph Campbell , John Hubbard , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, Christian =?iso-8859-1?Q?K=F6nig?= , linux-mm@kvack.org, =?iso-8859-1?B?Suly9G1l?= Glisse , Ben Skeggs , nouveau@lists.freedesktop.org, Alex Deucher , "Kuehling, Felix" , intel-gfx@lists.freedesktop.org, Christoph Hellwig Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Wed, Apr 22, 2020 at 09:39:11AM -0300, Jason Gunthorpe wrote: > > Nice callchain from hell.. Unfortunately such "code listings" tend to > > get out of date very quickly, so I'm not sure it is worth keeping in > > the code. What would be really worthile is consolidating the two > > different sets of defines (NVIF_VMM_PFNMAP_V0_ vs NVKM_VMM_PFN_) > > to make the code a little easier to follow. > > I was mainly concerned that this function is using hmm properly, > becuase it sure looks like it is just forming the CPU physical address > into a HW specific data. But it turns out it is just an internal data > for some other code and the dma_map is impossibly far away > > It took forever to find, I figured I'd leave a hint for the next poor > soul that has to look at this.. > > Also, I think it shows there is no 'performance' argument here, if > this path needs more performance the above should be cleaned > before we abuse hmm_range_fault. > > Put it in the commit message instead? Yes, the graph itself sounds reasonable for the commit log as a point of time information. > > > npages = (range->end - range->start) >> PAGE_SHIFT; > > > for (i = 0; i < npages; ++i) { > > > struct page *page; > > > > > > + if (!(range->hmm_pfns[i] & HMM_PFN_VALID)) { > > > + ioctl_addr[i] = 0; > > > continue; > > > + } > > > > Can't we rely on the caller pre-zeroing the array? > > This ends up as args.phys in nouveau_svm_fault - I didn't see a > zeroing? > > I think it makes sense that this routine fully sets the output array > and does not assume pre-initialize Ok. _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx