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[195.135.220.15]) by mx.google.com with ESMTPS id w4si8070463edd.42.2019.06.10.11.58.06 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 10 Jun 2019 11:58:06 -0700 (PDT) Received-SPF: softfail (google.com: domain of transitioning mhocko@kernel.org does not designate 195.135.220.15 as permitted sender) client-ip=195.135.220.15; Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning mhocko@kernel.org does not designate 195.135.220.15 as permitted sender) smtp.mailfrom=mhocko@kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 7B8E2ABC7; Mon, 10 Jun 2019 18:58:05 +0000 (UTC) Date: Mon, 10 Jun 2019 20:58:04 +0200 From: Michal Hocko To: Konstantin Khlebnikov Cc: linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org, Cyrill Gorcunov , Kirill Tkhai , Al Viro Subject: Re: [PATCH 2/5] proc: use down_read_killable for /proc/pid/smaps_rollup Message-ID: <20190610185804.GB2388@dhcp22.suse.cz> References: <155790967258.1319.11531787078240675602.stgit@buzz> <155790967469.1319.14744588086607025680.stgit@buzz> <20190517124555.GB1825@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) 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 Sun 09-06-19 12:07:36, Konstantin Khlebnikov wrote: [...] > > > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c > > > index 2bf210229daf..781879a91e3b 100644 > > > --- a/fs/proc/task_mmu.c > > > +++ b/fs/proc/task_mmu.c > > > @@ -832,7 +832,10 @@ static int show_smaps_rollup(struct seq_file *m, void *v) > > > memset(&mss, 0, sizeof(mss)); > > > - down_read(&mm->mmap_sem); > > > + ret = down_read_killable(&mm->mmap_sem); > > > + if (ret) > > > + goto out_put_mm; > > > > Why not ret = -EINTR. The seq_file code seems to be handling all errors > > AFAICS. > > > > I've missed your comment. Sorry. > > down_read_killable returns 0 for success and exactly -EINTR for failure. You are right of course. I must have misread the code at the time. Sorry about that. -- Michal Hocko SUSE Labs