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Darwish" CC: , Peter Xu , Linus Torvalds , Andrea Arcangeli , Andrew Morton , Aneesh Kumar K.V , Christoph Hellwig , Hugh Dickins , Jan Kara , Jann Horn , John Hubbard , Kirill Shutemov , Kirill Tkhai , Leon Romanovsky , Linux-MM , Michal Hocko , Oleg Nesterov Subject: Re: [PATCH v4 2/2] mm: prevent gup_fast from racing with COW during fork Message-ID: <20201112143128.GJ2620339@nvidia.com> References: <0-v4-908497cf359a+4782-gup_fork_jgg@nvidia.com> <2-v4-908497cf359a+4782-gup_fork_jgg@nvidia.com> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: BL1PR13CA0202.namprd13.prod.outlook.com (2603:10b6:208:2be::27) To DM6PR12MB3834.namprd12.prod.outlook.com (2603:10b6:5:14a::12) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from mlx.ziepe.ca (156.34.48.30) by BL1PR13CA0202.namprd13.prod.outlook.com (2603:10b6:208:2be::27) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3564.21 via Frontend Transport; Thu, 12 Nov 2020 14:31:29 +0000 Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1kdDdI-003hZR-IX; Thu, 12 Nov 2020 10:31:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1605191493; bh=yVdky61F6KZNabRcH0vGKsdl7uxBaz6X11Fma1OiCVo=; h=ARC-Seal:ARC-Message-Signature:ARC-Authentication-Results:Date: From:To:CC:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:X-ClientProxiedBy:MIME-Version: X-MS-Exchange-MessageSentRepresentingType; b=BGcDBMRvbkb8u92CsFWHiktfoMQ4Uc/HnD8KAOgTOzNciH8/d+QHZ8l/y4o4S48K7 DySEagmhW85WlVrj/Qhlkz9Tc92oybSu4WT1nIlxCA5trr/JdM4FjAa/NrdsaBve3b +ruYQVZisa1Mt/W4RKsLJ0pypPU2RGw+5guOzjtvHwwzU+qTku+WsW1kzQAKllo5Dl mPo2M6GifFFbbgbpw1vKrxjecqq/q+/pmBfJXyCc7m0ZgjcS9In5R8bzUbzrP6WS83 1K25XF1Elg6wT0+VcFKxcK+3fiR6EGwBA6tl/71ZyaQDqVoxRA+KxvHZP1fTDvDh4b /3l3GnzL2MnxA== 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, Nov 12, 2020 at 08:41:58AM +0100, Ahmed S. Darwish wrote: > On Tue, Nov 10, 2020 at 07:44:09PM -0400, Jason Gunthorpe wrote: > ... > > > > Fixes: f3c64eda3e50 ("mm: avoid early COW write protect games during fork()") > > Suggested-by: Linus Torvalds > > Link: https://lore.kernel.org/r/CAHk-=wi=iCnYCARbPGjkVJu9eyYeZ13N64tZYLdOB8CP5Q_PLw@mail.gmail.com > > Reviewed-by: John Hubbard > > Reviewed-by: Jan Kara > > Signed-off-by: Jason Gunthorpe > > Thanks for the v3 and v4 updates. > > For the seqcount_t parts: > > Acked-by: "Ahmed S. Darwish" Thank you for your help! Jason