From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754895AbaA1ItR (ORCPT ); Tue, 28 Jan 2014 03:49:17 -0500 Received: from cantor2.suse.de ([195.135.220.15]:53336 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754684AbaA1ItP (ORCPT ); Tue, 28 Jan 2014 03:49:15 -0500 Date: Tue, 28 Jan 2014 08:49:11 +0000 From: Mel Gorman To: Andrew Morton Cc: Rik van Riel , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: numa: Initialse numa balancing after jump label initialisation Message-ID: <20140128084911.GM4963@suse.de> References: <20140127155127.GJ4963@suse.de> <20140127144336.6e9428d317bc2f476fa8de3e@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20140127144336.6e9428d317bc2f476fa8de3e@linux-foundation.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 27, 2014 at 02:43:36PM -0800, Andrew Morton wrote: > On Mon, 27 Jan 2014 15:51:27 +0000 Mel Gorman wrote: > > > The command line parsing takes place before jump labels are initialised which > > generates a warning if numa_balancing= is specified and CONFIG_JUMP_LABEL > > is set. On older kernls before commit c4b2c0c5 (static_key: WARN on > > usage before jump_label_init was called) the kernel would have crashed. > > This patch enables automatic numa balancing later in the initialisation > > process if numa_balancing= is specified. > > > > ... > > > > @@ -2666,9 +2666,14 @@ static void __init check_numabalancing_enable(void) > > if (IS_ENABLED(CONFIG_NUMA_BALANCING_DEFAULT_ENABLED)) > > numabalancing_default = true; > > > > + /* Parsed by setup_numabalancing. override == 1 enables, -1 disables */ > > + if (numabalancing_override) > > + set_numabalancing_state(numabalancing_override == 1); > > + > > if (nr_node_ids > 1 && !numabalancing_override) { > > - printk(KERN_INFO "Enabling automatic NUMA balancing. " > > - "Configure with numa_balancing= or sysctl"); > > + printk(KERN_INFO "%s automatic NUMA balancing. " > > + "Configure with numa_balancing= or sysctl", > > + numabalancing_default ? "Enabling" : "Disabling"); > > set_numabalancing_state(numabalancing_default); > > } > > } > > Current mainline is a bit different from this: > > printk(KERN_INFO "Enabling automatic NUMA balancing. " > "Configure with numa_balancing= or the kernel.numa_balancing sysctl"); > > So this won't apply as-is to -stable. > That's ok. > I assume you suggested the -stable backport to fix the > it-crashes-before-c4b2c0c5 thing, so it isn't really needed in 3.12.x. > I am recommending this patch for -stable because 3.12.x crashes. c4b2c0c5 prevents a crash but it is still the case that the parameter is not handled properly so backporting c4b2c0c5 is not a suitable alternative. > Or something. Please sort all that out when Greg comes back with > a hey-that-didnt-apply. I will. -- Mel Gorman SUSE Labs