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=-13.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 2D568C47082 for ; Sat, 5 Jun 2021 04:20:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 06F206140F for ; Sat, 5 Jun 2021 04:20:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229994AbhFEEWN (ORCPT ); Sat, 5 Jun 2021 00:22:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59944 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229485AbhFEEWM (ORCPT ); Sat, 5 Jun 2021 00:22:12 -0400 Received: from mail-lf1-x134.google.com (mail-lf1-x134.google.com [IPv6:2a00:1450:4864:20::134]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CA7B3C061766 for ; Fri, 4 Jun 2021 21:20:08 -0700 (PDT) Received: by mail-lf1-x134.google.com with SMTP id v8so17063837lft.8 for ; Fri, 04 Jun 2021 21:20:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=MHI92OzbTRuOfSGogKDicdkw31a8xsuWOtLJPqvNx58=; b=hMgR5HN4yLicvtzTkSenR0cUmaDMZ2bwQfTgqhAeBKkYQcwNCoeTgDZnEobu//usT8 Ay/dOOX+J6E7bJRr1XvMPGgkoPiBmdX/2xqSg4Vo/W4VrAXO8PjhbgR9yQwpkcG6nlLc fbSbfa7bfIC6dmEr9rWwGKtkDi8RmjSZPBvphT0Cy+BprGCLoZauID7MlPnWzO2oeVnj W6ncU98HPZzq8jlGTu5Jn0PazLejKzS6xdoK7HomnNLR4CDiAtYCpS9t6mX+ejA6rgCS MiqK8pSbDacX5XdtYXY4wYvzqcnyf+9CXm5yqWHtv880W6cgl7d+qF4GLWNLYoWwX9z8 t2kg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=MHI92OzbTRuOfSGogKDicdkw31a8xsuWOtLJPqvNx58=; b=kJlGXi04Ab9SNn3KCKrTMGGFhMk8ZhHtvbGPUAMFfkQTrz//gD/P71lHrIJ7xq77xF ZlryQ6GFBBCPmsxqAnLEOOwlIlSdhrLnoadTv032ASyMO76XEk2zep2Yx1QfIn0tDBwE QeXtWaMLl7tqB6ZU/E2vkXo36J2DMmyWv8ZiV1s/TVt3/wI4Vw6izWVbv/S8VNdEKPDG CkDoYnQNEnNxbCMAI2EIZ4S+qCMcm0Md6HbW6XobugUZ7v/G4xweZtBDxNeGU3K2Qr4Z WQ1yiyKWhfDogrrxUh9XJd1S6Xxexki/y2+2KLJOYkOh+zYonFG00GD0e0X1ihvN35VX JBsQ== X-Gm-Message-State: AOAM530yCXKgBMDodLLz7MN49xcoKF7Tu+4gkS7y5wSDVgFiVlc53aUk LInIn9y+iqRNluXlNmMy/O0GK8vb+UfBFTcMRmNszw== X-Google-Smtp-Source: ABdhPJzxYihxXg8hJVDo1Cgn/BkB4ckK/wPvPVxczOItEciBDrO1zlGB84+NZGpQvumQ3vq3TiIiFzC4d9tPVTCKElo= X-Received: by 2002:a19:da12:: with SMTP id r18mr4769335lfg.549.1622866806719; Fri, 04 Jun 2021 21:20:06 -0700 (PDT) MIME-Version: 1.0 References: <20210524132725.12697-1-apopple@nvidia.com> <20210524132725.12697-4-apopple@nvidia.com> <20210525183710.fa2m2sbfixnhz7g5@revolver> <20210604204934.sbspsmwdqdtmz73d@revolver> <20210605033926.pkeq2saomieebrqa@revolver> In-Reply-To: <20210605033926.pkeq2saomieebrqa@revolver> From: Shakeel Butt Date: Fri, 4 Jun 2021 21:19:55 -0700 Message-ID: Subject: Re: [PATCH v9 03/10] mm/rmap: Split try_to_munlock from try_to_unmap To: Liam Howlett Cc: Alistair Popple , "linux-mm@kvack.org" , "akpm@linux-foundation.org" , "nouveau@lists.freedesktop.org" , "bskeggs@redhat.com" , "rcampbell@nvidia.com" , "linux-doc@vger.kernel.org" , "jhubbard@nvidia.com" , "bsingharora@gmail.com" , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , "hch@infradead.org" , "jglisse@redhat.com" , "willy@infradead.org" , "jgg@nvidia.com" , "peterx@redhat.com" , "hughd@google.com" , Christoph Hellwig Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 4, 2021 at 8:39 PM Liam Howlett wrote: > > > Particularly the following paragraph: > > ... > > Vlastimil Babka points out another race which this patch protects against. > > try_to_unmap_one() might reach its mlock_vma_page() TestSetPageMlocked a > > moment after munlock_vma_pages_all() did its Phase 1 TestClearPageMlocked: > > leaving PageMlocked and unevictable when it should be evictable. mmap_sem > > is ineffective because exit_mmap() does not hold it; page lock ineffective > > because __munlock_pagevec() only takes it afterwards, in Phase 2; pte lock > > is effective because __munlock_pagevec_fill() takes it to get the page, > > after VM_LOCKED was cleared from vm_flags, so visible to try_to_unmap_one. > > ... > > So this is saying the race with exit_mmap() isn't benign after all? > Yes, not benign at all. 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=-13.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 2D0E6C47082 for ; Sat, 5 Jun 2021 06:23:34 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BBB7B6121F for ; Sat, 5 Jun 2021 06:23:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BBB7B6121F Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 21D7D6B0036; 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Fri, 04 Jun 2021 21:20:06 -0700 (PDT) MIME-Version: 1.0 References: <20210524132725.12697-1-apopple@nvidia.com> <20210524132725.12697-4-apopple@nvidia.com> <20210525183710.fa2m2sbfixnhz7g5@revolver> <20210604204934.sbspsmwdqdtmz73d@revolver> <20210605033926.pkeq2saomieebrqa@revolver> In-Reply-To: <20210605033926.pkeq2saomieebrqa@revolver> From: Shakeel Butt Date: Fri, 4 Jun 2021 21:19:55 -0700 Message-ID: Subject: Re: [PATCH v9 03/10] mm/rmap: Split try_to_munlock from try_to_unmap To: Liam Howlett Cc: Alistair Popple , "linux-mm@kvack.org" , "akpm@linux-foundation.org" , "nouveau@lists.freedesktop.org" , "bskeggs@redhat.com" , "rcampbell@nvidia.com" , "linux-doc@vger.kernel.org" , "jhubbard@nvidia.com" , "bsingharora@gmail.com" , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , "hch@infradead.org" , "jglisse@redhat.com" , "willy@infradead.org" , "jgg@nvidia.com" , "peterx@redhat.com" , "hughd@google.com" , Christoph Hellwig Content-Type: text/plain; charset="UTF-8" Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=google.com header.s=20161025 header.b=hMgR5HN4; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf29.hostedemail.com: domain of shakeelb@google.com designates 209.85.208.170 as permitted sender) smtp.mailfrom=shakeelb@google.com X-Stat-Signature: xoygqf1o6rjse87wn5ce3mga3zmotpzh X-Rspamd-Queue-Id: 6FD422701 X-Rspamd-Server: rspam02 X-HE-Tag: 1622874195-758161 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 Fri, Jun 4, 2021 at 8:39 PM Liam Howlett wrote: > > > Particularly the following paragraph: > > ... > > Vlastimil Babka points out another race which this patch protects against. > > try_to_unmap_one() might reach its mlock_vma_page() TestSetPageMlocked a > > moment after munlock_vma_pages_all() did its Phase 1 TestClearPageMlocked: > > leaving PageMlocked and unevictable when it should be evictable. mmap_sem > > is ineffective because exit_mmap() does not hold it; page lock ineffective > > because __munlock_pagevec() only takes it afterwards, in Phase 2; pte lock > > is effective because __munlock_pagevec_fill() takes it to get the page, > > after VM_LOCKED was cleared from vm_flags, so visible to try_to_unmap_one. > > ... > > So this is saying the race with exit_mmap() isn't benign after all? > Yes, not benign at all. 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spf=none smtp.mailfrom=nouveau-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AD28D6E046; Sun, 6 Jun 2021 17:34:23 +0000 (UTC) Received: from mail-lf1-x134.google.com (mail-lf1-x134.google.com [IPv6:2a00:1450:4864:20::134]) by gabe.freedesktop.org (Postfix) with ESMTPS id A11266E466 for ; Sat, 5 Jun 2021 04:20:08 +0000 (UTC) Received: by mail-lf1-x134.google.com with SMTP id n12so10061889lft.10 for ; Fri, 04 Jun 2021 21:20:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=MHI92OzbTRuOfSGogKDicdkw31a8xsuWOtLJPqvNx58=; b=hMgR5HN4yLicvtzTkSenR0cUmaDMZ2bwQfTgqhAeBKkYQcwNCoeTgDZnEobu//usT8 Ay/dOOX+J6E7bJRr1XvMPGgkoPiBmdX/2xqSg4Vo/W4VrAXO8PjhbgR9yQwpkcG6nlLc fbSbfa7bfIC6dmEr9rWwGKtkDi8RmjSZPBvphT0Cy+BprGCLoZauID7MlPnWzO2oeVnj W6ncU98HPZzq8jlGTu5Jn0PazLejKzS6xdoK7HomnNLR4CDiAtYCpS9t6mX+ejA6rgCS MiqK8pSbDacX5XdtYXY4wYvzqcnyf+9CXm5yqWHtv880W6cgl7d+qF4GLWNLYoWwX9z8 t2kg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=MHI92OzbTRuOfSGogKDicdkw31a8xsuWOtLJPqvNx58=; b=LdrglnQVmtTOTDL3seXA9r9BOgp61tvj+GE8obXpYJTxfVymfCdmNChBNIcVztfJph vovzd8UcSIkEhrAC8pRDUhca5SmogIrQGCp8k+Tje3ke7pn42h32qFgUQgBlhn7uSmVN b77+cK4/isx0CMibr8RVSmwQKLEZEVMfT0LsbqYGaVwpIaCWzXJzINHUBXtboZxgeKzV dqj/5YLaivFlq81zlGdOjzrO/tV8jTEgksZ1FGEU+QL7JYUQQDAhIQutBw8rf79D5+We fzTs3en2kwloQld46jcLYJ7Ssa5suGHRC0lvdm8k7KPRC/+Zi8msMninu56TseO5STEj bMyw== X-Gm-Message-State: AOAM532mU5w9WNBfyE7dUAM7hQV5NodocMYngWSUJDEq3UcVRp03KBQY P2jG1mpTScOKTZ9x1GLVgfjCWDR2hRBq1kPgRMShwQ== X-Google-Smtp-Source: ABdhPJzxYihxXg8hJVDo1Cgn/BkB4ckK/wPvPVxczOItEciBDrO1zlGB84+NZGpQvumQ3vq3TiIiFzC4d9tPVTCKElo= X-Received: by 2002:a19:da12:: with SMTP id r18mr4769335lfg.549.1622866806719; Fri, 04 Jun 2021 21:20:06 -0700 (PDT) MIME-Version: 1.0 References: <20210524132725.12697-1-apopple@nvidia.com> <20210524132725.12697-4-apopple@nvidia.com> <20210525183710.fa2m2sbfixnhz7g5@revolver> <20210604204934.sbspsmwdqdtmz73d@revolver> <20210605033926.pkeq2saomieebrqa@revolver> In-Reply-To: <20210605033926.pkeq2saomieebrqa@revolver> From: Shakeel Butt Date: Fri, 4 Jun 2021 21:19:55 -0700 Message-ID: To: Liam Howlett X-Mailman-Approved-At: Sun, 06 Jun 2021 17:34:23 +0000 Subject: Re: [Nouveau] [PATCH v9 03/10] mm/rmap: Split try_to_munlock from try_to_unmap X-BeenThere: nouveau@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Nouveau development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "rcampbell@nvidia.com" , "willy@infradead.org" , "linux-doc@vger.kernel.org" , "nouveau@lists.freedesktop.org" , "bsingharora@gmail.com" , Alistair Popple , "hughd@google.com" , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , "peterx@redhat.com" , "hch@infradead.org" , "linux-mm@kvack.org" , "bskeggs@redhat.com" , "jgg@nvidia.com" , "akpm@linux-foundation.org" , Christoph Hellwig Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: nouveau-bounces@lists.freedesktop.org Sender: "Nouveau" On Fri, Jun 4, 2021 at 8:39 PM Liam Howlett wrote: > > > Particularly the following paragraph: > > ... > > Vlastimil Babka points out another race which this patch protects against. > > try_to_unmap_one() might reach its mlock_vma_page() TestSetPageMlocked a > > moment after munlock_vma_pages_all() did its Phase 1 TestClearPageMlocked: > > leaving PageMlocked and unevictable when it should be evictable. mmap_sem > > is ineffective because exit_mmap() does not hold it; page lock ineffective > > because __munlock_pagevec() only takes it afterwards, in Phase 2; pte lock > > is effective because __munlock_pagevec_fill() takes it to get the page, > > after VM_LOCKED was cleared from vm_flags, so visible to try_to_unmap_one. > > ... > > So this is saying the race with exit_mmap() isn't benign after all? > Yes, not benign at all. _______________________________________________ Nouveau mailing list Nouveau@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/nouveau 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=-3.5 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 66013C47082 for ; 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Fri, 04 Jun 2021 21:20:06 -0700 (PDT) MIME-Version: 1.0 References: <20210524132725.12697-1-apopple@nvidia.com> <20210524132725.12697-4-apopple@nvidia.com> <20210525183710.fa2m2sbfixnhz7g5@revolver> <20210604204934.sbspsmwdqdtmz73d@revolver> <20210605033926.pkeq2saomieebrqa@revolver> In-Reply-To: <20210605033926.pkeq2saomieebrqa@revolver> From: Shakeel Butt Date: Fri, 4 Jun 2021 21:19:55 -0700 Message-ID: Subject: Re: [PATCH v9 03/10] mm/rmap: Split try_to_munlock from try_to_unmap To: Liam Howlett Content-Type: text/plain; charset="UTF-8" X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "rcampbell@nvidia.com" , "willy@infradead.org" , "linux-doc@vger.kernel.org" , "nouveau@lists.freedesktop.org" , "bsingharora@gmail.com" , Alistair Popple , "hughd@google.com" , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , "peterx@redhat.com" , "hch@infradead.org" , "linux-mm@kvack.org" , "jglisse@redhat.com" , "bskeggs@redhat.com" , "jgg@nvidia.com" , "jhubbard@nvidia.com" , "akpm@linux-foundation.org" , Christoph Hellwig Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Fri, Jun 4, 2021 at 8:39 PM Liam Howlett wrote: > > > Particularly the following paragraph: > > ... > > Vlastimil Babka points out another race which this patch protects against. > > try_to_unmap_one() might reach its mlock_vma_page() TestSetPageMlocked a > > moment after munlock_vma_pages_all() did its Phase 1 TestClearPageMlocked: > > leaving PageMlocked and unevictable when it should be evictable. mmap_sem > > is ineffective because exit_mmap() does not hold it; page lock ineffective > > because __munlock_pagevec() only takes it afterwards, in Phase 2; pte lock > > is effective because __munlock_pagevec_fill() takes it to get the page, > > after VM_LOCKED was cleared from vm_flags, so visible to try_to_unmap_one. > > ... > > So this is saying the race with exit_mmap() isn't benign after all? > Yes, not benign at all.