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=-2.5 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT 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 688B1C32789 for ; Fri, 2 Nov 2018 08:04:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C57D2081B for ; Fri, 2 Nov 2018 08:04:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C57D2081B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728502AbeKBRKP (ORCPT ); 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