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, 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 2AB35C76195 for ; Fri, 19 Jul 2019 06:05:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F00CE2085A for ; Fri, 19 Jul 2019 06:05:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563516308; bh=n3CZev3O1v6RoQnaenGtvgjTod4iK+wLjwOBdqmGIo8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=t41jC5JYLzDDHD2AvjnQ6Xmb6dMuuuXDxgDA9o+i5vIigZs/IoDFPhW+BB7TADB8+ KQ9zscDtJzaM8KONtQImKI497wsJ41XM2a3dUCE4ivX2Ug/+/OTHjL2y4BUUX6QWsS Hw5f2IWieNnKK+uzzllTsY6va8jCEeMdfvp6krvs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727153AbfGSGFG (ORCPT ); Fri, 19 Jul 2019 02:05:06 -0400 Received: from mx2.suse.de ([195.135.220.15]:59594 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726072AbfGSGFG (ORCPT ); Fri, 19 Jul 2019 02:05:06 -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 6FB6CB0B3; Fri, 19 Jul 2019 06:05:04 +0000 (UTC) Date: Fri, 19 Jul 2019 08:05:02 +0200 From: Michal Hocko To: David Hildenbrand Cc: Oscar Salvador , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-arm-kernel@lists.infradead.org, akpm@linux-foundation.org, Dan Williams , Wei Yang , Igor Mammedov , Greg Kroah-Hartman , "Rafael J. Wysocki" , Alex Deucher , "David S. Miller" , Mark Brown , Chris Wilson , Jonathan Cameron Subject: Re: [PATCH v3 10/11] mm/memory_hotplug: Make unregister_memory_block_under_nodes() never fail Message-ID: <20190719060502.GG30461@dhcp22.suse.cz> References: <20190527111152.16324-1-david@redhat.com> <20190527111152.16324-11-david@redhat.com> <20190701085144.GJ6376@dhcp22.suse.cz> <20190701093640.GA17349@linux> <20190701102756.GO6376@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 Mon 15-07-19 13:10:33, David Hildenbrand wrote: > On 01.07.19 12:27, Michal Hocko wrote: > > On Mon 01-07-19 11:36:44, Oscar Salvador wrote: > >> On Mon, Jul 01, 2019 at 10:51:44AM +0200, Michal Hocko wrote: > >>> Yeah, we do not allow to offline multi zone (node) ranges so the current > >>> code seems to be over engineered. > >>> > >>> Anyway, I am wondering why do we have to strictly check for already > >>> removed nodes links. Is the sysfs code going to complain we we try to > >>> remove again? > >> > >> No, sysfs will silently "fail" if the symlink has already been removed. > >> At least that is what I saw last time I played with it. > >> > >> I guess the question is what if sysfs handling changes in the future > >> and starts dropping warnings when trying to remove a symlink is not there. > >> Maybe that is unlikely to happen? > > > > And maybe we handle it then rather than have a static allocation that > > everybody with hotremove configured has to pay for. > > > > So what's the suggestion? Dropping the nodemask_t completely and calling > sysfs_remove_link() on already potentially removed links? Yes. In a follow up patch. -- Michal Hocko SUSE Labs