Re: [PATCH] change global zonelist order on NUMA v2

KAMEZAWA Hiroyuki
2007-04-27T00:41:17Z

On Thu, 26 Apr 2007 17:57:40 -0400
Lee Schermerhorn <Lee.Schermerhorn@hp.com> wrote:

> On Thu, 2007-04-26 at 18:34 +0900, KAMEZAWA Hiroyuki wrote:
> > Changelog from V1 -> V2
> > - sysctl name is changed to be relaxed_zone_order
> > - NORMAL->NORMAL->....->DMA->DMA->DMA order (new ordering) is now default.
> > NORMAL->DMA->NORMAL->DMA order (old ordering) is optional.
> > - addes boot opttion to set relaxed_zone_order. ia64 is supported now.
> > - Added documentation
> >
> > patch is against 2.6.21-rc7-mm2. tested on ia64 NUMA box. works well.
>
> [PATCH] factor/rework change zonelist order patch
>
> Against 2.6.21-rc7 atop KAMEZAWA Hiroyuki's "change global zonelist
> order on NUMA v2" patch.
>
Hi, this looks 'easier-to-read' than mine. thanks.

> 3) kept early_param() definition for boot parameter in mm/page_alloc.c,
> along with the handler function. One less file to modify.
>
I put early_param() to arch dependent part just beacause no generic code
except for pci seems to call it. If it is allowed, I welcome this change.

> 4) modified the two Documentation additions to match these changes.
>

> I've tested various combinations [non-exhaustive], with an ad hoc
> instrumentation patch, and it appears to work as expected [as I expect,
> anyway] on ia64 NUMA.
>
> Question: do we need to rebuild the zonelist caches when we reorder
> the zones? The z_to_n[] array appears to be dependent on
> the zonelist order...
>
maybe no.

> Also: I see the "Movable" zones show up in 21-rc7-mm2. This patch
> will cause Movable zone to overflow to remote movable zones
> before using local Normal memory in non-default, zone order.
> Is this what we want?
>
>From my point of view, it's what I want. What we have to do will be
establish a way to create ZONE_MOVABLE with suitable size on each node.

I'll merge your change to my set and add "automatic detection" support.

Thank you.
-Kame