[Patch] x86_64 hot-add memroy srat.c fix

[Patch] x86_64 hot-add memroy srat.c fix

[keith mannthey]

  This patch corrects the logic used in srat.c to figure out what
parsing what action to take when registering hot-add areas.  Hot-add
areas should only be added to the node information for the
MEMORY_HOTPLGU_RESERVE case.  When booting MEMORY_HOTPLUG_SPARSE hot-add
areas on everything but the last node are getting include in the node
data and during kernel boot the pages are setup then the kernel dies
when the pages are used. This patch fixes this issue.  It is based
against 2.6.19-rc1.  

Signed-off-by: Keith Mannthey <kmannth@us.ibm.com> 
---
srat.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff -urN linux-2.6.18/arch/x86_64/mm/srat.c linux-2.6.18-rc1/arch/x86_64/mm/srat.c
--- linux-2.6.18/arch/x86_64/mm/srat.c	2006-10-06 17:17:04.000000000 -0400
+++ linux-2.6.18-rc1/arch/x86_64/mm/srat.c	2006-10-06 16:29:59.000000000 -0400
@@ -207,7 +207,7 @@
 	return hotadd_percent > 0;
 }
 #else
-int update_end_of_memory(unsigned long end) {return 0;}
+int update_end_of_memory(unsigned long end) {return -1;}
 static int hotadd_enough_memory(struct bootnode *nd) {return 1;}
 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
 static inline int save_add_info(void) {return 1;}
@@ -337,7 +337,7 @@
 	push_node_boundaries(node, nd->start >> PAGE_SHIFT,
 						nd->end >> PAGE_SHIFT);
 
- 	if (ma->flags.hot_pluggable && !reserve_hotadd(node, start, end) < 0) {
+ 	if (ma->flags.hot_pluggable && (reserve_hotadd(node, start, end) < 0)) {
 		/* Ignore hotadd region. Undo damage */
 		printk(KERN_NOTICE "SRAT: Hotplug region ignored\n");
 		*nd = oldnode;

Re: [Patch] x86_64 hot-add memroy srat.c fix

[Andi Kleen]

On Saturday 07 October 2006 00:53, keith mannthey wrote:
>   This patch corrects the logic used in srat.c to figure out what
> parsing what action to take when registering hot-add areas.  Hot-add
> areas should only be added to the node information for the
> MEMORY_HOTPLGU_RESERVE case.  When booting MEMORY_HOTPLUG_SPARSE hot-add
> areas on everything but the last node are getting include in the node
> data and during kernel boot the pages are setup then the kernel dies
> when the pages are used. This patch fixes this issue.  It is based
> against 2.6.19-rc1.  

Added thanks, especially since it's a obvious typo.

If that patch was added to .19 does sparsemem hotadd work then or does it
need more patches?

-Andi

Re: [Patch] x86_64 hot-add memroy srat.c fix

[keith mannthey]

On Mon, 2006-10-16 at 12:01 +0200, Andi Kleen wrote:
> On Saturday 07 October 2006 00:53, keith mannthey wrote:
> >   This patch corrects the logic used in srat.c to figure out what
> > parsing what action to take when registering hot-add areas.  Hot-add
> > areas should only be added to the node information for the
> > MEMORY_HOTPLGU_RESERVE case.  When booting MEMORY_HOTPLUG_SPARSE hot-add
> > areas on everything but the last node are getting include in the node
> > data and during kernel boot the pages are setup then the kernel dies
> > when the pages are used. This patch fixes this issue.  It is based
> > against 2.6.19-rc1.  
> 
> Added thanks, especially since it's a obvious typo.
Yea...  Something pre 2.6.19 was removing the e820 reserved area before
the nodes were brought online (and thus masking the problem during
testing). 

> If that patch was added to .19 does sparsemem hotadd work then or does it
> need more patches?

SPARSEMEM hot-add will work in .19 if this patch is applied.  

Thanks,
  Keith