Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754831Ab2KMKph (ORCPT ); Tue, 13 Nov 2012 05:45:37 -0500 Received: from mail-ee0-f46.google.com ([74.125.83.46]:61547 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754783Ab2KMKpg (ORCPT ); Tue, 13 Nov 2012 05:45:36 -0500 Date: Tue, 13 Nov 2012 11:45:30 +0100 From: Ingo Molnar To: Mel Gorman Cc: Peter Zijlstra , Andrea Arcangeli , Rik van Riel , Johannes Weiner , Hugh Dickins , Thomas Gleixner , Linus Torvalds , Andrew Morton , Linux-MM , LKML Subject: Re: [PATCH 15/19] mm: numa: Add fault driven placement and migration Message-ID: <20121113104530.GF21522@gmail.com> References: <1352193295-26815-1-git-send-email-mgorman@suse.de> <1352193295-26815-16-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1352193295-26815-16-git-send-email-mgorman@suse.de> 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 Content-Length: 2170 Lines: 64 * Mel Gorman wrote: > NOTE: This patch is based on "sched, numa, mm: Add fault driven > placement and migration policy" but as it throws away > all the policy to just leave a basic foundation I had to > drop the signed-offs-by. So, much of that has been updated meanwhile - but the split makes fundamental sense - we considered it before. One detail you did in this patch was the following rename: s/EMBEDDED_NUMA/NUMA_VARIABLE_LOCALITY > --- a/arch/sh/mm/Kconfig > +++ b/arch/sh/mm/Kconfig > @@ -111,6 +111,7 @@ config VSYSCALL > config NUMA > bool "Non Uniform Memory Access (NUMA) Support" > depends on MMU && SYS_SUPPORTS_NUMA && EXPERIMENTAL > + select NUMA_VARIABLE_LOCALITY > default n > help > Some SH systems have many various memories scattered around > diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h > ..aaba45d 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -696,6 +696,20 @@ config LOG_BUF_SHIFT > config HAVE_UNSTABLE_SCHED_CLOCK > bool > > +# > +# For architectures that (ab)use NUMA to represent different memory regions > +# all cpu-local but of different latencies, such as SuperH. > +# > +config NUMA_VARIABLE_LOCALITY > + bool The NUMA_VARIABLE_LOCALITY name slightly misses the real point though that NUMA_EMBEDDED tried to stress: it's important to realize that these are systems that (ab-)use our NUMA memory zoning code to implement support for variable speed RAM modules - so they can use the existing node binding ABIs. The cost of that is the losing of the regular NUMA node structure. So by all means it's a convenient hack - but the name must signal that. I'm not attached to the NUMA_EMBEDDED naming overly strongly, but NUMA_VARIABLE_LOCALITY sounds more harmless than it should. Perhaps ARCH_WANT_NUMA_VARIABLE_LOCALITY_OVERRIDE? A tad long but we don't want it to be overused in any case. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/