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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_NEOMUTT autolearn=unavailable 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 73A68C04AB4 for ; Thu, 16 May 2019 16:30:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C74D2082E for ; Thu, 16 May 2019 16:30:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727122AbfEPQ3w (ORCPT ); Thu, 16 May 2019 12:29:52 -0400 Received: from mail-wm1-f68.google.com ([209.85.128.68]:35799 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726964AbfEPQ3t (ORCPT ); Thu, 16 May 2019 12:29:49 -0400 Received: by mail-wm1-f68.google.com with SMTP id q15so4138276wmj.0 for ; Thu, 16 May 2019 09:29:48 -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:in-reply-to:user-agent; bh=bmJ3oGbhkIfE+oGMXz0i/1fqw7BH4scbuPzlcTLdX0o=; b=LqiV9D6Ghpb4aXnQor+QWgNaddHzAVkuW/6LpF+d4LvRNoQL6uujnn6+eV4DoVWMs4 Rh+QQZDwGK9eFp1H4RUOobWq14ylZcgktFfiLU8YNDzJwgDA1tmQBZQTTo055yZUlZZh PrpsvOstihWpMH/SGhjYTLh3Pmrre5SbjcqFjX3AageSqO64CJNauz1DgzA/2dNS/avz hKWDgyFtm1RvgfofWNgasScifHoer2bEs+Q0CFHKKvHDlgPj3ZkdzQY81ufj/o4xGTtR fBvT5a7+Qsm8zZTIIbjAiTt4YaKFETs2RnJv/hbmK1X59d4W4f1XVongAAd+Kvx/lA4B BNhw== X-Gm-Message-State: APjAAAUjlKbm7YaG1DdB/AM22tebYLRaP3CFVlVm3NJ0Ket46/8699C5 y0GrimIptKWXn9767I0dT465 X-Google-Smtp-Source: APXvYqw4xzsO/ZHDRK8RT2D9NZpnGvFVdO15DLWHiBOzYw0vUAqtOT7NkS6GGg4mfAYLcWMR8bMLaA== X-Received: by 2002:a1c:e714:: with SMTP id e20mr18848944wmh.143.1558024187943; Thu, 16 May 2019 09:29:47 -0700 (PDT) Received: from localhost (cpc111743-lutn13-2-0-cust844.9-3.cable.virginm.net. [82.17.115.77]) by smtp.gmail.com with ESMTPSA id l8sm7695747wrw.56.2019.05.16.09.29.46 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 16 May 2019 09:29:47 -0700 (PDT) Date: Thu, 16 May 2019 17:29:46 +0100 From: Aaron Tomlin To: Jann Horn Cc: Oleksandr Natalenko , kernel list , Kirill Tkhai , Hugh Dickins , Alexey Dobriyan , Vlastimil Babka , Michal Hocko , Matthew Wilcox , Pavel Tatashin , Greg KH , Suren Baghdasaryan , Minchan Kim , Timofey Titovets , Grzegorz Halat , Linux-MM , Linux API Subject: Re: [PATCH RFC 4/5] mm/ksm, proc: introduce remote merge Message-ID: <20190516162946.zwzhxkft342b25pd@atomlin.usersys.com> References: <20190516094234.9116-1-oleksandr@redhat.com> <20190516094234.9116-5-oleksandr@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-PGP-Key: http://pgp.mit.edu/pks/lookup?search=atomlin%40redhat.com X-PGP-Fingerprint: 7906 84EB FA8A 9638 8D1E 6E9B E2DE 9658 19CC 77D6 User-Agent: NeoMutt/20180716-1637-ee8449 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 2019-05-16 12:00 +0200, Jann Horn wrote: > On Thu, May 16, 2019 at 11:43 AM Oleksandr Natalenko > wrote: [ ... ] > > + } > > + > > + down_write(&mm->mmap_sem); > > Should a check for mmget_still_valid(mm) be inserted here? See commit > 04f5866e41fb70690e28397487d8bd8eea7d712a. Yes - I'd say this is required here. Thanks, -- Aaron Tomlin