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From: Ingo Molnar <mingo@kernel.org>
To: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Rik van Riel <riel@redhat.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Hugh Dickins <hughd@google.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linux-MM <linux-mm@kvack.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 15/19] mm: numa: Add fault driven placement and migration
Date: Tue, 13 Nov 2012 11:45:30 +0100	[thread overview]
Message-ID: <20121113104530.GF21522@gmail.com> (raw)
In-Reply-To: <1352193295-26815-16-git-send-email-mgorman@suse.de>


* Mel Gorman <mgorman@suse.de> 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

  parent reply	other threads:[~2012-11-13 10:45 UTC|newest]

Thread overview: 65+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-06  9:14 [RFC PATCH 00/19] Foundation for automatic NUMA balancing Mel Gorman
2012-11-06  9:14 ` [PATCH 01/19] mm: compaction: Move migration fail/success stats to migrate.c Mel Gorman
2012-11-06 17:32   ` Rik van Riel
2012-11-06  9:14 ` [PATCH 02/19] mm: migrate: Add a tracepoint for migrate_pages Mel Gorman
2012-11-06 17:33   ` Rik van Riel
2012-11-06  9:14 ` [PATCH 03/19] mm: compaction: Add scanned and isolated counters for compaction Mel Gorman
2012-11-06 17:35   ` Rik van Riel
2012-11-06  9:14 ` [PATCH 04/19] mm: numa: define _PAGE_NUMA Mel Gorman
2012-11-06 18:35   ` Rik van Riel
2012-11-06  9:14 ` [PATCH 05/19] mm: numa: pte_numa() and pmd_numa() Mel Gorman
2012-11-13  9:54   ` Ingo Molnar
2012-11-13 11:24     ` Mel Gorman
2012-11-06  9:14 ` [PATCH 06/19] mm: numa: teach gup_fast about pmd_numa Mel Gorman
2012-11-13 10:07   ` Ingo Molnar
2012-11-13 11:37     ` Mel Gorman
2012-11-13 13:51       ` Ingo Molnar
2012-11-06  9:14 ` [PATCH 07/19] mm: numa: split_huge_page: transfer the NUMA type from the pmd to the pte Mel Gorman
2012-11-06  9:14 ` [PATCH 08/19] mm: numa: Create basic numa page hinting infrastructure Mel Gorman
2012-11-06 18:58   ` Rik van Riel
2012-11-07 10:38     ` Mel Gorman
2012-11-07 10:48       ` Rik van Riel
2012-11-07 11:00         ` Mel Gorman
2012-11-13 10:21   ` Ingo Molnar
2012-11-13 11:50     ` Mel Gorman
2012-11-13 13:49       ` Ingo Molnar
2012-11-13 14:26         ` Mel Gorman
2012-11-06  9:14 ` [PATCH 09/19] mm: mempolicy: Make MPOL_LOCAL a real policy Mel Gorman
2012-11-06  9:14 ` [PATCH 10/19] mm: mempolicy: Add MPOL_MF_NOOP Mel Gorman
2012-11-06  9:14 ` [PATCH 11/19] mm: mempolicy: Check for misplaced page Mel Gorman
2012-11-06  9:14 ` [PATCH 12/19] mm: migrate: Introduce migrate_misplaced_page() Mel Gorman
2012-11-06 19:10   ` Rik van Riel
2012-11-13  9:36   ` Ingo Molnar
2012-11-13 11:43     ` Ingo Molnar
2012-11-13 11:56       ` Mel Gorman
2012-11-13 14:49       ` Rik van Riel
2012-11-06  9:14 ` [PATCH 13/19] mm: mempolicy: Use _PAGE_NUMA to migrate pages Mel Gorman
2012-11-06 19:18   ` Rik van Riel
2012-11-07 12:32     ` Mel Gorman
2012-11-06  9:14 ` [PATCH 14/19] mm: mempolicy: Add MPOL_MF_LAZY Mel Gorman
2012-11-06 19:19   ` Rik van Riel
2012-11-13 10:25   ` Ingo Molnar
2012-11-13 12:02     ` Mel Gorman
2012-11-06  9:14 ` [PATCH 15/19] mm: numa: Add fault driven placement and migration Mel Gorman
2012-11-06 19:41   ` Rik van Riel
2012-11-07 10:49     ` Mel Gorman
2012-11-07 11:46       ` Rik van Riel
2012-11-13 10:45   ` Ingo Molnar [this message]
2012-11-13 12:09     ` Mel Gorman
2012-11-13 13:39       ` Ingo Molnar
2012-11-06  9:14 ` [PATCH 16/19] mm: numa: Add pte updates, hinting and migration stats Mel Gorman
2012-11-06 19:55   ` Rik van Riel
2012-11-07 10:57     ` Mel Gorman
2012-11-07 11:47       ` Rik van Riel
2012-11-06  9:14 ` [PATCH 17/19] mm: numa: Migrate on reference policy Mel Gorman
2012-11-07 11:56   ` Rik van Riel
2012-11-06  9:14 ` [PATCH 18/19] mm: sched: numa: Implement constant, per task Working Set Sampling (WSS) rate Mel Gorman
2012-11-06 19:55   ` Rik van Riel
2012-11-06  9:14 ` [PATCH 19/19] mm: sched: numa: Implement slow start for working set sampling Mel Gorman
2012-11-06 19:56   ` Rik van Riel
2012-11-07  9:27 ` [RFC PATCH 00/19] Foundation for automatic NUMA balancing Zhouping Liu
2012-11-07 15:25   ` Mel Gorman
2012-11-08  6:37     ` Zhouping Liu
     [not found]       ` <CAOHXNFG=T63dmc3smkJ2juE7HpxTv6qbavBXycRsXiLBzAwMGw@mail.gmail.com>
2012-11-08  7:03         ` Zhouping Liu
2012-11-09 14:42 ` Andrea Arcangeli
2012-11-09 16:12   ` Mel Gorman

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