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 B0007ECDE43 for ; Thu, 18 Oct 2018 07:00:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 70DAA20644 for ; Thu, 18 Oct 2018 07:00:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 70DAA20644 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 S1727643AbeJRPAH (ORCPT ); Thu, 18 Oct 2018 11:00:07 -0400 Received: from mx2.suse.de ([195.135.220.15]:33018 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727337AbeJRPAG (ORCPT ); Thu, 18 Oct 2018 11:00:06 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id EA477B006; Thu, 18 Oct 2018 07:00:32 +0000 (UTC) Date: Thu, 18 Oct 2018 09:00:31 +0200 From: Michal Hocko To: David Rientjes Cc: Andrew Morton , Vlastimil Babka , Alexey Dobriyan , "Kirill A. Shutemov" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org Subject: Re: [RFC PATCH] mm, proc: report PR_SET_THP_DISABLE in proc Message-ID: <20181018070031.GW18839@dhcp22.suse.cz> References: <20181004094637.GG22173@dhcp22.suse.cz> <20181009083326.GG8528@dhcp22.suse.cz> <20181015150325.GN18839@dhcp22.suse.cz> <20181016104855.GQ18839@dhcp22.suse.cz> <20181017070531.GC18839@dhcp22.suse.cz> 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 Wed 17-10-18 12:59:18, David Rientjes wrote: > On Wed, 17 Oct 2018, Michal Hocko wrote: > > > Do you know of any other userspace except your usecase? Is there > > anything fundamental that would prevent a proper API adoption for you? > > > > Yes, it would require us to go back in time and build patched binaries. I read that as there is a fundamental problem to update existing binaries. If that is the case then there surely is no way around it and another sad page in the screwed up APIs book we provide. But I was under impression that the SW stack which actually does the monitoring is under your controll. Moreover I was under impression that you do not use the current vanilla kernel so there is no need for an immediate change on your end. It is trivial to come up with a backward compatible way to check for the new flag (if it is not present then fallback to vma flags). I am sorry for pushing here but if this is just a matter of a _single_ user which _can_ be fixed with a reasonable effort then I would love to see the future api unscrewed. -- Michal Hocko SUSE Labs