[PATCH RESEND]mm/ia64: fix a node distance bug

[PATCH RESEND]mm/ia64: fix a node distance bug

[wujianguo]

From: Jianguo Wu <wujianguo@huawei.com>

In arch ia64, has following definition:
extern u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];
#define node_distance(from,to) (numa_slit[(from) * num_online_nodes() + (to)])

num_online_nodes() is a variable value, it can be changed after hot-remove/add
a node.

I my practice, I found node distance is wrong after offline
a node in IA64 platform. For example system has 4 nodes:
node distances:
node   0   1   2   3
  0:  10  21  21  32
  1:  21  10  32  21
  2:  21  32  10  21
  3:  32  21  21  10

linux-drf:/sys/devices/system/node/node0 # cat distance
10  21  21  32
linux-drf:/sys/devices/system/node/node1 # cat distance
21  10  32  21

After offline node2:
linux-drf:/sys/devices/system/node/node0 # cat distance
10 21 32
linux-drf:/sys/devices/system/node/node1 # cat distance
32 21 32	--------->expected value is: 21  10  21


Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
---
 arch/ia64/include/asm/numa.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/ia64/include/asm/numa.h b/arch/ia64/include/asm/numa.h
index 6a8a27c..2e27ef1 100644
--- a/arch/ia64/include/asm/numa.h
+++ b/arch/ia64/include/asm/numa.h
@@ -59,7 +59,7 @@ extern struct node_cpuid_s node_cpuid[NR_CPUS];
  */

 extern u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];
-#define node_distance(from,to) (numa_slit[(from) * num_online_nodes() + (to)])
+#define node_distance(from,to) (numa_slit[(from) * MAX_NUMNODES + (to)])

 extern int paddr_to_nid(unsigned long paddr);

-- 1.7.6.1 .

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Re: [PATCH RESEND]mm/ia64: fix a node distance bug

[David Rientjes]

On Thu, 6 Sep 2012, wujianguo wrote:

> From: Jianguo Wu <wujianguo@huawei.com>
> 
> In arch ia64, has following definition:
> extern u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];
> #define node_distance(from,to) (numa_slit[(from) * num_online_nodes() + (to)])
> 
> num_online_nodes() is a variable value, it can be changed after hot-remove/add
> a node.
> 
> I my practice, I found node distance is wrong after offline
> a node in IA64 platform. For example system has 4 nodes:
> node distances:
> node   0   1   2   3
>   0:  10  21  21  32
>   1:  21  10  32  21
>   2:  21  32  10  21
>   3:  32  21  21  10
> 
> linux-drf:/sys/devices/system/node/node0 # cat distance
> 10  21  21  32
> linux-drf:/sys/devices/system/node/node1 # cat distance
> 21  10  32  21
> 
> After offline node2:
> linux-drf:/sys/devices/system/node/node0 # cat distance
> 10 21 32
> linux-drf:/sys/devices/system/node/node1 # cat distance
> 32 21 32	--------->expected value is: 21  10  21
> 
> 
> Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
> Signed-off-by: Jiang Liu <jiang.liu@huawei.com>

Acked-by: David Rientjes <rientjes@google.com>

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Re: [PATCH RESEND]mm/ia64: fix a node distance bug

[Tony Luck]

On Fri, Sep 7, 2012 at 3:58 PM, David Rientjes <rientjes@google.com> wrote:
> On Thu, 6 Sep 2012, wujianguo wrote:
>> Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
>> Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
>
> Acked-by: David Rientjes <rientjes@google.com>

Applied (should show up in linux-next in the next day or two).

-Tony

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