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_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 9F3D0C282D7 for ; Wed, 30 Jan 2019 16:51:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 61B742086C for ; Wed, 30 Jan 2019 16:51:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548867063; bh=foRi73XmZpyT2S6Lfh2ScdyDo7AuATJqrfRuvggPlUo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=LCFdgoNIYAoES8FjM+EHkv2ivsVc8JwulgatrVAs9l4vlReMtja1CXsvHrNQphanr RwLAK/vIhY9thhhZ7KOJoLmr4YjkhYCk5bLe5S1eJf0TJVeIVQNvZAg7WjHKRzirMK +vlqje6qHWfWc3asNpp88xTVI8fXhEfNqamdZqeI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732216AbfA3QvC (ORCPT ); Wed, 30 Jan 2019 11:51:02 -0500 Received: from mx2.suse.de ([195.135.220.15]:34700 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728469AbfA3QvB (ORCPT ); Wed, 30 Jan 2019 11:51:01 -0500 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 42860AFCE; Wed, 30 Jan 2019 16:51:00 +0000 (UTC) Date: Wed, 30 Jan 2019 17:50:58 +0100 From: Michal Hocko To: Tejun Heo Cc: Johannes Weiner , Chris Down , Andrew Morton , Roman Gushchin , Dennis Zhou , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, kernel-team@fb.com Subject: Re: [PATCH 2/2] mm: Consider subtrees in memory.events Message-ID: <20190130165058.GA18811@dhcp22.suse.cz> References: <20190128125151.GI18811@dhcp22.suse.cz> <20190128142816.GM50184@devbig004.ftw2.facebook.com> <20190128145210.GM18811@dhcp22.suse.cz> <20190128145407.GP50184@devbig004.ftw2.facebook.com> <20190128151859.GO18811@dhcp22.suse.cz> <20190128154150.GQ50184@devbig004.ftw2.facebook.com> <20190128170526.GQ18811@dhcp22.suse.cz> <20190128174905.GU50184@devbig004.ftw2.facebook.com> <20190129144306.GO18811@dhcp22.suse.cz> <20190129145240.GX50184@devbig004.ftw2.facebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190129145240.GX50184@devbig004.ftw2.facebook.com> 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 Tue 29-01-19 06:52:40, Tejun Heo wrote: > Hello, > > On Tue, Jan 29, 2019 at 03:43:06PM +0100, Michal Hocko wrote: > > All memcg events are represented non-hierarchical AFAICS > > memcg_memory_event() simply accounts at the level when it happens. Or do > > I miss something? Or are you talking about .events files for other > > controllers? > > Yeah, cgroup.events and .stat files as some of the local stats would > be useful too, so if we don't flip memory.events we'll end up with sth > like cgroup.events.local, memory.events.tree and memory.stats.local, > which is gonna be hilarious. Why cannot we simply have memory.events_tree and be done with it? Sure the file names are not goin to be consistent which is a minus but that ship has already sailed some time ago. > If you aren't willing to change your mind, the only option seems to be > introducing a mount option to gate the flip and additions of local > files. Most likely, userspace will enable the option by default > everywhere, so the end result will be exactly the same but I guess > it'll better address your concern. How does the consumer of the API learns about the mount type? -- Michal Hocko SUSE Labs