From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f43.google.com (mail-ee0-f43.google.com [74.125.83.43]) by kanga.kvack.org (Postfix) with ESMTP id 213246B0031 for ; Tue, 28 Jan 2014 03:49:16 -0500 (EST) Received: by mail-ee0-f43.google.com with SMTP id c41so56130eek.16 for ; Tue, 28 Jan 2014 00:49:15 -0800 (PST) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id g47si25949484eet.192.2014.01.28.00.49.14 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Tue, 28 Jan 2014 00:49:14 -0800 (PST) Date: Tue, 28 Jan 2014 08:49:11 +0000 From: Mel Gorman 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> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Rik van Riel , linux-mm@kvack.org, 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org