Re: [PATCH] Fake NUMA emulation for PowerPC (Take 2)

From: Michael Ellerman
Date: Fri Jan 18 2008 - 00:45:15 EST


On Fri, 2008-01-18 at 16:34 +1100, Michael Ellerman wrote:
> On Sat, 2007-12-08 at 04:07 +0530, Balbir Singh wrote:
> > Changelog
> >
> > 1. Get rid of the constant 5 (based on comments from
> > Geert.Uytterhoeven@xxxxxxxxxxx)
> > 2. Implement suggestions from Olof Johannson
> > 3. Check if cmdline is NULL in fake_numa_create_new_node()
> >
> > Tested with additional parameters from Olof
> >
> > numa=debug,fake=
> > numa=foo,fake=bar
>
>
> I'm not sure why yet, but git bisect tells me it's this patch that's
> causing the for-2.6.25 tree to explode on boot on cell machines.

This fixes it, although I'm a little worried about some of the
removals/movings of node_set_online() in the patch.


diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 1666e7d..dcedc26 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -49,7 +49,6 @@ static int __cpuinit fake_numa_create_new_node(unsigned long end_pfn,
static unsigned int fake_nid = 0;
static unsigned long long curr_boundary = 0;

- *nid = fake_nid;
if (!p)
return 0;

@@ -60,6 +59,7 @@ static int __cpuinit fake_numa_create_new_node(unsigned long end_pfn,
if (mem < curr_boundary)
return 0;

+ *nid = fake_nid;
curr_boundary = mem;

if ((end_pfn << PAGE_SHIFT) > mem) {

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