From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx204.postini.com [74.125.245.204]) by kanga.kvack.org (Postfix) with SMTP id C5E706B0006 for ; Thu, 11 Apr 2013 08:48:09 -0400 (EDT) Date: Thu, 11 Apr 2013 13:48:03 +0100 From: Mel Gorman Subject: Re: [PATCH] mm: Print the correct method to disable automatic numa migration Message-ID: <20130411124803.GK3710@suse.de> References: <1365622514-26614-1-git-send-email-andi@firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1365622514-26614-1-git-send-email-andi@firstfloor.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andi Kleen Cc: akpm@linux-foundation.org, linux-mm@kvack.org, Andi Kleen On Wed, Apr 10, 2013 at 12:35:14PM -0700, Andi Kleen wrote: > From: Andi Kleen > > When the "default y" CONFIG_NUMA_BALANCING_DEFAULT_ENABLED is enabled, > the message it prints refers to a sysctl to disable it again. > But that sysctl doesn't exist. > True. > Document the correct (highly obscure method) through debugfs. > > This should be also in Documentation/* but isn't. > > Also fix the checkpatch problems. > > BTW I think the "default y" is highly dubious for such a > experimential feature. > As David pointed out, CONFIG_NUMA_BALANCING_DEFAULT_ENABLED only comes into play when CONFIG_NUMA_BALANCING is set and CONFIG_NUMA_BALANCING will default to N for make oldconfig. I think it's sensible to enable it by default if it's configured in. David has also already pointed out the problems with NO_NUMA vs -NUMA and the fact that the option only exists if CONFIG_SCHED_DEBUG which I agree is unfortunate. Ends up with this sort of mess printk(KERN_INFO "Enabling automatic NUMA balancing. " "Configure with numa_balancing=" #ifdef CONFIG_SCHED_DEBUG " or echo [NO_]NUMA > /sys/kernel/debug/sched_features" #endif ".\n"); -- 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