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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 54E41C4338F for ; Fri, 6 Aug 2021 10:15:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E1BA26101C for ; Fri, 6 Aug 2021 10:15:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org E1BA26101C Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 213678D0001; Fri, 6 Aug 2021 06:15:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1C53D6B0071; Fri, 6 Aug 2021 06:15:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0B2BE8D0001; Fri, 6 Aug 2021 06:15:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0063.hostedemail.com [216.40.44.63]) by kanga.kvack.org (Postfix) with ESMTP id E89506B006C for ; Fri, 6 Aug 2021 06:15:04 -0400 (EDT) Received: from smtpin32.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id A0781181AF5D7 for ; Fri, 6 Aug 2021 10:15:04 +0000 (UTC) X-FDA: 78444247728.32.51BF1F5 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf28.hostedemail.com (Postfix) with ESMTP id 46CCB90072D8 for ; Fri, 6 Aug 2021 10:15:04 +0000 (UTC) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id E01A222369; Fri, 6 Aug 2021 10:15:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1628244902; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=QFGRy0TVO6Sv+kOUDL6gKJLzvhAhsmyj9YyaOQWydKs=; b=syvPzm/lthsXkM5NM4glpb2MPQNmaSopqfCTTaMkrKi5PbeuC8rIgUdn27XRNSTHYiK0+O 85ZkxXSjmmCRROz5BZ4PpgyIGbd+6jgPfCWwvkCDFmSETl56dvEi6BbGb81OvhaYpQutMv q4fxt2MEFHLW3OZXZreuY1B2dKlEaX4= Received: from suse.cz (unknown [10.100.201.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 47BE0A3B85; Fri, 6 Aug 2021 10:15:02 +0000 (UTC) Date: Fri, 6 Aug 2021 12:15:01 +0200 From: Michal Hocko To: Shakeel Butt Cc: Suren Baghdasaryan , Andrew Morton , David Rientjes , Matthew Wilcox , Johannes Weiner , Roman Gushchin , Rik van Riel , Minchan Kim , Christian Brauner , Christoph Hellwig , Oleg Nesterov , David Hildenbrand , Jann Horn , Andy Lutomirski , Christian Brauner , Florian Weimer , Jan Engelhardt , Tim Murray , Linux API , Linux MM , LKML , kernel-team Subject: Re: [PATCH v7 1/2] mm: introduce process_mrelease system call Message-ID: References: <20210805170859.2389276-1-surenb@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 46CCB90072D8 Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b="syvPzm/l"; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf28.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.28 as permitted sender) smtp.mailfrom=mhocko@suse.com X-Stat-Signature: 1s7iknwe9cynf5sub7a7quo8ouhsjahk X-HE-Tag: 1628244904-915346 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 Fri 06-08-21 02:23:17, Shakeel Butt wrote: > On Thu, Aug 5, 2021 at 11:40 PM Michal Hocko wrote: > > > [...] > > I think you really want something like this: > > > > if (flags) > > return -EINVAL; > > > > pid = pidfd_get_pid(fd, &f_flags); > > if (IS_ERR(pid)) > > return PTR_ERR(pid); > > task = get_pid_task(pid, PIDTYPE_PID); > > if (!task) { > > ret = -ESRCH; > > goto put_pid; > > } > > > > /* > > * Make sure to chose a thread which still has a reference to mm > > * during the group exit > > */ > > p = find_lock_task_mm(task); > > if (!p) { > > ret = -ESRCH; > > goto put_task; > > } > > > > mm = task->mm; > > mm = p->mm; right. Thanks! -- Michal Hocko SUSE Labs