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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D1A2C43217 for ; Fri, 28 Jan 2022 16:52:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350322AbiA1Qwj (ORCPT ); Fri, 28 Jan 2022 11:52:39 -0500 Received: from ale.deltatee.com ([204.191.154.188]:39510 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350321AbiA1Qwh (ORCPT ); Fri, 28 Jan 2022 11:52:37 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:In-Reply-To:MIME-Version:Date: Message-ID:From:References:Cc:To:content-disposition; bh=TwdFNzdxDdgz+26v8ucb90p5GLD0CB3VYearw7eL4TE=; b=Jjmj+T8NaOnEcL6xfeeEEnDoy1 Jwe8ThuF6gDiurLsgr0uGnv9DtwA/YJGSAnk4YZieWRprMNN1XZTwMxLvg1xLTfdEF5shDUo1oKVB dGm8uPC2nP7BeAAxYGpVDjN5PUUN2dF+lmH4w3GEZWrOcUdeidJ3eaZUbWN7mRLo4ueWSGNDBPHcA n16IZ9yCMCIyGHmi5gDa34nnEEktr//UIijZEjTEMKttvW/djXEMc19q3vTDkuYD11X80MS+G2fw6 WeaxTsJGGnS1Qt8qyvAZPSnnzqFXDE1edRZ8gpanjHUFDkfU4ljqOz+DMGoVetIUcDrsOOBqJRnuy Yyx62grQ==; Received: from s0106a84e3fe8c3f3.cg.shawcable.net ([24.64.144.200] helo=[192.168.0.10]) by ale.deltatee.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94.2) (envelope-from ) id 1nDUTz-0068Ws-Uv; Fri, 28 Jan 2022 09:52:20 -0700 To: Jason 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 , =?UTF-8?Q?Christian_K=c3=b6nig?= , 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 References: <20220128002614.6136-1-logang@deltatee.com> <20220128002614.6136-23-logang@deltatee.com> <20220128142251.GV8034@ziepe.ca> From: Logan Gunthorpe Message-ID: <8ca5e74e-b02b-427f-cf7b-485f8153d689@deltatee.com> Date: Fri, 28 Jan 2022 09:52:18 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: <20220128142251.GV8034@ziepe.ca> Content-Type: text/plain; charset=utf-8 Content-Language: en-CA Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 24.64.144.200 X-SA-Exim-Rcpt-To: rcampbell@nvidia.com, ckulkarnilinux@gmail.com, martin.oliveira@eideticom.com, robin.murphy@arm.com, ira.weiny@intel.com, helgaas@kernel.org, jianxin.xiong@intel.com, dave.hansen@linux.intel.com, jason@jlekstrand.net, dave.b.minturn@intel.com, andrzej.jakowski@intel.com, daniel.vetter@ffwll.ch, willy@infradead.org, ddutile@redhat.com, jhubbard@nvidia.com, christian.koenig@amd.com, dan.j.williams@intel.com, hch@lst.de, sbates@raithlin.com, iommu@lists.linux-foundation.org, linux-mm@kvack.org, linux-pci@vger.kernel.org, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, jgg@ziepe.ca X-SA-Exim-Mail-From: logang@deltatee.com Subject: Re: [PATCH v5 22/24] mm: use custom page_free for P2PDMA pages X-SA-Exim-Version: 4.2.1 (built Sat, 13 Feb 2021 17:57:42 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022-01-28 7:22 a.m., Jason Gunthorpe wrote: > 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? Right, yes. Thanks, Logan