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=2.2 required=3.0 tests=CHARSET_FARAWAY_HEADER, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 B8048C43381 for ; Fri, 15 Feb 2019 00:58:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 807D021934 for ; Fri, 15 Feb 2019 00:58:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730210AbfBOA6C (ORCPT ); Thu, 14 Feb 2019 19:58:02 -0500 Received: from www262.sakura.ne.jp ([202.181.97.72]:17638 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726461AbfBOA6C (ORCPT ); Thu, 14 Feb 2019 19:58:02 -0500 Received: from fsav305.sakura.ne.jp (fsav305.sakura.ne.jp [153.120.85.136]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id x1F0vxYI076972; Fri, 15 Feb 2019 09:57:59 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav305.sakura.ne.jp (F-Secure/fsigk_smtp/530/fsav305.sakura.ne.jp); Fri, 15 Feb 2019 09:57:59 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/530/fsav305.sakura.ne.jp) Received: from www262.sakura.ne.jp (localhost [127.0.0.1]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id x1F0vxME076967; Fri, 15 Feb 2019 09:57:59 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Received: (from i-love@localhost) by www262.sakura.ne.jp (8.15.2/8.15.2/Submit) id x1F0vxHb076966; Fri, 15 Feb 2019 09:57:59 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Message-Id: <201902150057.x1F0vxHb076966@www262.sakura.ne.jp> X-Authentication-Warning: www262.sakura.ne.jp: i-love set sender to penguin-kernel@i-love.sakura.ne.jp using -f Subject: Re: [PATCH] proc, oom: do not report alien mms when setting =?ISO-2022-JP?B?b29tX3Njb3JlX2Fkag==?= From: Tetsuo Handa To: Michal Hocko Cc: Andrew Morton , David Rientjes , Johannes Weiner , Linus Torvalds , Yong-Taek Lee , linux-mm@kvack.org, LKML MIME-Version: 1.0 Date: Fri, 15 Feb 2019 09:57:59 +0900 References: <201902130124.x1D1OGg3070046@www262.sakura.ne.jp> <20190213114733.GB4525@dhcp22.suse.cz> In-Reply-To: <20190213114733.GB4525@dhcp22.suse.cz> Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sigh, you are again misunderstanding... I'm not opposing to forbid CLONE_VM without CLONE_SIGHAND threading model. I'm asserting that we had better revert the iteration for now, even if we will strive towards forbidding CLONE_VM without CLONE_SIGHAND threading model. You say "And that is a correctness issue." but your patch is broken because your patch does not close the race. Since nobody seems to be using CLONE_VM without CLONE_SIGHAND threading, we can both avoid hungtask problem and close the race by eliminating this broken iteration. We don't need to worry about "This could easily lead to breaking the OOM_SCORE_ADJ_MIN protection." case because setting OOM_SCORE_ADJ_MIN needs administrator's privilege. And it is YOUR PATCH that still allows leading to breaking the OOM_SCORE_ADJ_MIN protection. My patch is more simpler and accurate than your patch.