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=-1.0 required=3.0 tests=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 E982FC2BA19 for ; Tue, 21 Apr 2020 07:27:03 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B11292074B for ; Tue, 21 Apr 2020 07:27:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B11292074B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 39D418E0005; Tue, 21 Apr 2020 03:27:03 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 34EDC8E0003; Tue, 21 Apr 2020 03:27:03 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 23D888E0005; Tue, 21 Apr 2020 03:27:03 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0249.hostedemail.com [216.40.44.249]) by kanga.kvack.org (Postfix) with ESMTP id 08FB98E0003 for ; Tue, 21 Apr 2020 03:27:03 -0400 (EDT) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id C27BF181AEF1E for ; Tue, 21 Apr 2020 07:27:02 +0000 (UTC) X-FDA: 76731030684.21.drop92_3466d47a740a X-HE-Tag: drop92_3466d47a740a X-Filterd-Recvd-Size: 3079 Received: from mail-wm1-f66.google.com (mail-wm1-f66.google.com [209.85.128.66]) by imf03.hostedemail.com (Postfix) with ESMTP for ; Tue, 21 Apr 2020 07:27:02 +0000 (UTC) Received: by mail-wm1-f66.google.com with SMTP id h2so2350108wmb.4 for ; Tue, 21 Apr 2020 00:27:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=r+LS7G4wEEtDWQ4xCceTw9hFXAaQ/q1kZGVg/52bph0=; b=f9P1LnZlgG49JJpBVZreEps+k7B09uXkFLxOpdt3yC6oW61o4OSvXRLfXzim/Jqr9f gephJ91nS3SGPpe/FS0IbBR/GpDfCXNbbeNeo1LT3P2aLnmC3vCOUTHlxcnKHIL3SXXo H76MMiUx4kprByHQF6rMMk5AQXlfrPryi7OZMGbxwWLYVcgsldkiMcxKj2u31u4S1+v0 oY2nhjZ77zBV2jZ8hkniKVi16+042KwI+rQL7BkinJffZuhf7dExcnCGgqYNCNSNnYpt Og4GHl0xTeyNQ6Nj1xCD5CttzvzN4aL+unuMPqaYq0kWkqv8yHYs/cpJB4kqm2l/TtWv Pehw== X-Gm-Message-State: AGi0PubuRUOoPYeksROOYluQFn+Zo+ET/WcMAxkh4guSWl3wpWE9GFZu YHYZfG6rQTD66DdmyLAxTTc= X-Google-Smtp-Source: APiQypJIIt8jPsE3gICdeRRzuImS15/h9nCq/RSUU/JOHm9tHD0BXhTtFDwTPLw+DHYIFn3PTs0zQA== X-Received: by 2002:a1c:6241:: with SMTP id w62mr3335645wmb.27.1587454021493; Tue, 21 Apr 2020 00:27:01 -0700 (PDT) Received: from localhost (ip-37-188-130-62.eurotel.cz. [37.188.130.62]) by smtp.gmail.com with ESMTPSA id h3sm2459024wrm.73.2020.04.21.00.26.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 Apr 2020 00:27:00 -0700 (PDT) Date: Tue, 21 Apr 2020 09:26:59 +0200 From: Michal Hocko To: Li Xinhai Cc: akpm , "linux-mm@kvack.org" Subject: Re: [PATCH 0/3] mm: Fix misuse of parent anon_vma in dup_mmap path Message-ID: <20200421072659.GC27314@dhcp22.suse.cz> References: <1581150928-3214-1-git-send-email-lixinhai.lxh@gmail.com> <20200209165204.73197330d083095e0ad18d6c@linux-foundation.org> <2020021010155155113445@gmail.com> <20200420120628.GN27314@dhcp22.suse.cz> <2020042111530118847536@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <2020042111530118847536@gmail.com> Content-Transfer-Encoding: quoted-printable 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 Tue 21-04-20 11:53:02, Li Xinhai wrote: > On 2020-04-20=A0at 20:06=A0Michal Hocko=A0wrote: [...] > > Because from my current understanding it would > >only make WIPEONFORK vmas rmap walks less efficient. Or is there any > >other functional issue?=20 > #1 issue is for case=A0WIPEONFORK, #2 issue for all other cases of anon= ymous VMA dup > (i.e., when parent vmas is currently sharing anon_vma among themself, c= hild vma will > share its=A0parent vma's anon_vma). OK, it was not really clear to me that also !WIPEONFORK vmas are affected. Thanks for the clarification. --=20 Michal Hocko SUSE Labs