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Mon, 03 May 2021 18:24:42 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 6C9EA68B05; Mon, 3 May 2021 20:24:35 +0200 (CEST) Date: Mon, 3 May 2021 20:24:35 +0200 From: Christoph Hellwig To: John Hubbard Cc: Logan Gunthorpe , linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, Stephen Bates , Christoph Hellwig , Dan Williams , Jason Gunthorpe , Christian =?iso-8859-1?Q?K=F6nig?= , Don Dutile , Matthew Wilcox , Daniel Vetter , Jakowski Andrzej , Minturn Dave B , Jason Ekstrand , Dave Hansen , Xiong Jianxin , Bjorn Helgaas , Ira Weiny , Robin Murphy , Bjorn Helgaas Subject: Re: [PATCH 01/16] PCI/P2PDMA: Pass gfp_mask flags to upstream_bridge_distance_warn() Message-ID: <20210503182434.GA17174@lst.de> References: <20210408170123.8788-1-logang@deltatee.com> <20210408170123.8788-2-logang@deltatee.com> <8ea5b5b3-e10f-121a-bd2a-07db83c6da01@deltatee.com> <3bced3a4-b826-46ab-3d98-d2dc6871bfe1@nvidia.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <3bced3a4-b826-46ab-3d98-d2dc6871bfe1@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-20210503_112441_745089_7B8FC700 X-CRM114-Status: GOOD ( 15.14 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Mon, May 03, 2021 at 11:17:31AM -0700, John Hubbard wrote: > That's the thing: memory failure should be exceedingly rare for this. > Therefore, just fail out entirely (which I don't expect we'll likely > ever see), instead of doing all this weird stuff to try to continue > on if you cannot allocate a single page. If you are in that case, the > system is not in a state that is going to run your dma p2p setup well > anyway. > > I think it's *less* complexity to allocate up front, fail early if > allocation fails, and then not have to deal with these really odd > quirks at the lower levels. Agreed. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme