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[202.181.97.72]) by mx.google.com with ESMTPS id d195si1705765oih.212.2019.02.14.16.58.10 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 14 Feb 2019 16:58:10 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of penguin-kernel@i-love.sakura.ne.jp designates 202.181.97.72 as permitted sender) client-ip=202.181.97.72; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of penguin-kernel@i-love.sakura.ne.jp designates 202.181.97.72 as permitted sender) smtp.mailfrom=penguin-kernel@i-love.sakura.ne.jp 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 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: 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.