Received: by 2002:ac0:98c7:0:0:0:0:0 with SMTP id g7-v6csp1831121imd; Fri, 2 Nov 2018 01:04:36 -0700 (PDT) X-Google-Smtp-Source: AJdET5d9JY/vyh0y1NSECDu810a7UOhSRe0W5IEWaQwnD1NaOFMQwxKY732vqWHqjBTHtIjwuGCW X-Received: by 2002:a17:902:bf49:: with SMTP id u9-v6mr11026798pls.10.1541145876235; Fri, 02 Nov 2018 01:04:36 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1541145876; cv=none; d=google.com; s=arc-20160816; b=tO6cnViej9QeNjDRK+HtiTlYK0RwZuTfjFCROe9XOuvyGFHY2a4O4WO1Ga9FXdnamT pUT8JhqsGYwns5xr1Wifo8CCR3c8ioeNvgdq6Wdb9p1oKSvF146M26Jz65NghK6DVn2W e4MlWsO+HHI3GlQapWQ2K7vA/x1YO9sJNoKNldMKMA7uBvwEGlvTKVRQwlWQOrK2uPIX GD64c2tWmp0tCWCKwURD85QYL5N9KaO/aR4dJKWzdlWheLcxv6ArjyhfLFeaAXwT263G ljciq6f0ZL88GBw3BR690RvUyCAegjYLrTM6haJldfZFb7AjaZFoAuUs84oNIQf/Egfe S/Bg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=lSHJmD0d07OAK/Ux7XIe5fpt1H0qhjSRqZ6UxaH/Hgk=; b=fu0M0El55TBuziq8CAGoo6MBbLqIGgSO4wIPd+pLMKYKMXGzplGIV4YdFfX61ii8op DUKSi1lkBQZelGaZBsdT8v6edPx3De9zCwaG7XUXjWsX8Zk2PG3XFp6A9RhI06w3N3Zv P0DII3sm9TNjJh+ugaHO89YYwChL9P8/A+rbXbEYRyQPoE5S+/Z1s9Ky10SzWiTNo4Tu kJLBFptGysghTlcQ9E/GNi7Lg3cfsTEIt53QetTa96B9KXpXPVBtLsCREU6GdSfY5IRi 3nX6j0XAQDT/MXdncDLxdcENbCcLUWQ/z51ZfXh2qhXHmxWPMt+Y6VDNRrsQaoMQD+ZR fgjw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id i64-v6si20278940pli.135.2018.11.02.01.04.20; Fri, 02 Nov 2018 01:04:36 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728470AbeKBRKP (ORCPT + 99 others); Fri, 2 Nov 2018 13:10:15 -0400 Received: from mx2.suse.de ([195.135.220.15]:60984 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726713AbeKBRKP (ORCPT ); Fri, 2 Nov 2018 13:10:15 -0400 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 097CDAE15; Fri, 2 Nov 2018 08:03:57 +0000 (UTC) Date: Fri, 2 Nov 2018 09:03:55 +0100 From: Michal Hocko To: Dexuan Cui Cc: Roman Gushchin , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , Kernel Team , Shakeel Butt , Johannes Weiner , Tejun Heo , Rik van Riel , Konstantin Khlebnikov , Matthew Wilcox , "Stable@vger.kernel.org" Subject: Re: Will the recent memory leak fixes be backported to longterm kernels? Message-ID: <20181102073009.GP23921@dhcp22.suse.cz> References: <20181102005816.GA10297@tower.DHCP.thefacebook.com> 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) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 02-11-18 02:45:42, Dexuan Cui wrote: [...] > I totally agree. I'm now just wondering if there is any temporary workaround, > even if that means we have to run the kernel with some features disabled or > with a suboptimal performance? One way would be to disable kmem accounting (cgroup.memory=nokmem kernel option). That would reduce the memory isolation because quite a lot of memory will not be accounted for but the primary source of in-flight and hard to reclaim memory will be gone. Another workaround could be to use force_empty knob we have in v1 and use it when removing a cgroup. We do not have it in cgroup v2 though. The file hasn't been added to v2 because we didn't really have any proper usecase. Working around a bug doesn't sound like a _proper_ usecase but I can imagine workloads that bring a lot of metadata objects that are not really interesting for later use so something like a targeted drop_caches... -- Michal Hocko SUSE Labs