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[142.162.113.129]) by smtp.gmail.com with ESMTPSA id v22sm1250520qtc.96.2022.01.28.06.22.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Jan 2022 06:22:52 -0800 (PST) Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1nDS9L-007UYx-Hy; Fri, 28 Jan 2022 10:22:51 -0400 Date: Fri, 28 Jan 2022 10:22:51 -0400 From: Jason Gunthorpe To: Logan Gunthorpe Cc: 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 , Christian =?utf-8?B?S8O2bmln?= , John Hubbard , Don Dutile , Matthew Wilcox , Daniel Vetter , Jakowski Andrzej , Minturn Dave B , Jason Ekstrand , Dave Hansen , Xiong Jianxin , Bjorn Helgaas , Ira Weiny , Robin Murphy , Martin Oliveira , Chaitanya Kulkarni , Ralph Campbell Subject: Re: [PATCH v5 22/24] mm: use custom page_free for P2PDMA pages Message-ID: <20220128142251.GV8034@ziepe.ca> References: <20220128002614.6136-1-logang@deltatee.com> <20220128002614.6136-23-logang@deltatee.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220128002614.6136-23-logang@deltatee.com> X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 59B30160047 X-Stat-Signature: mqqy53947z9o9mqfotg1g5tugtcihgye X-Rspam-User: nil Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=ziepe.ca header.s=google header.b=U6c+XkFY; spf=pass (imf08.hostedemail.com: domain of jgg@ziepe.ca designates 209.85.219.42 as permitted sender) smtp.mailfrom=jgg@ziepe.ca; dmarc=none X-HE-Tag: 1643379773-368348 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: On Thu, Jan 27, 2022 at 05:26:12PM -0700, Logan Gunthorpe wrote: > When P2PDMA pages are passed to userspace, they will need to be > reference counted properly and returned to their genalloc after their > reference count returns to 1. This is accomplished with the existing It is reference count returns to 0 now, right? Jason