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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 8D48FC5ACAE for ; Wed, 11 Sep 2019 12:00:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5EFE22085B for ; Wed, 11 Sep 2019 12:00:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568203207; bh=TRZPhDUn3fCmyadj4io3KMR6sEvY1Axe1o0mYIWtiqU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=CYBKYqp6ltxpZAFwZCN1F6W69oOoZcklKs/GpiqWF0W+O1r6NcXPBnbUYCwCaXz6r yC+dKiIDfxOpjy5oOoyCal5X3f0tznwPdRimQqA9k++vGEMeo2JLuexYX339VdYJIJ SGdf9d/u2TPBkqq+73s87ZcKMNtA/kwS9I2B/R9Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727816AbfIKMAG (ORCPT ); Wed, 11 Sep 2019 08:00:06 -0400 Received: from mx2.suse.de ([195.135.220.15]:42922 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726702AbfIKMAG (ORCPT ); Wed, 11 Sep 2019 08:00:06 -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 7A9D9B64B; Wed, 11 Sep 2019 12:00:04 +0000 (UTC) Date: Wed, 11 Sep 2019 14:00:02 +0200 From: Michal Hocko To: Shakeel Butt Cc: Andrew Morton , Johannes Weiner , Vladimir Davydov , LKML , Linux MM , Andrey Ryabinin , Thomas Lindroth , Tetsuo Handa Subject: Re: [PATCH] memcg, kmem: do not fail __GFP_NOFAIL charges Message-ID: <20190911120002.GQ4023@dhcp22.suse.cz> References: <31131c2d-a936-8bbf-e58d-a3baaa457340@gmail.com> <20190906125608.32129-1-mhocko@kernel.org> <20190909112245.GH27159@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190909112245.GH27159@dhcp22.suse.cz> 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 Mon 09-09-19 13:22:45, Michal Hocko wrote: > On Fri 06-09-19 11:24:55, Shakeel Butt wrote: [...] > > I wonder what has changed since > > . > > I have completely forgot about that one. It seems that we have just > repeated the same discussion again. This time we have a poor user who > actually enabled the kmem limit. > > I guess there was no real objection to the change back then. The primary > discussion revolved around the fact that the accounting will stay broken > even when this particular part was fixed. Considering this leads to easy > to trigger crash (with the limit enabled) then I guess we should just > make it less broken and backport to stable trees and have a serious > discussion about discontinuing of the limit. Start by simply failing to > set any limit in the current upstream kernels. Any more concerns/objections to the patch? I can add a reference to your earlier post Shakeel if you want or to credit you the way you prefer. Also are there any objections to start deprecating process of kmem limit? I would see it in two stages - 1st warn in the kernel log pr_warn("kmem.limit_in_bytes is deprecated and will be removed. "Please report your usecase to linux-mm@kvack.org if you " "depend on this functionality." - 2nd fail any write to kmem.limit_in_bytes - 3rd remove the control file completely -- Michal Hocko SUSE Labs