On 2016/8/26 23:29, Will Deacon wrote:

On Wed, Aug 24, 2016 at 03:44:49PM +0800, Zhen Lei wrote:

quoted

1. MAX_NUMNODES is base on CONFIG_NODES_SHIFT, the default value of the
   latter is very small now.
2. Suppose the default value of MAX_NUMNODES is enlarged to 64, so the
   size of numa_distance is 4K, it's still acceptable if run the Image
   on other processors.
3. It will make function __node_distance quicker than before.

Signed-off-by: Zhen Lei <redacted>
---
 arch/arm64/include/asm/numa.h |  1 -
 arch/arm64/mm/numa.c          | 74 +++----------------------------------------
 2 files changed, 5 insertions(+), 70 deletions(-)

I fail to see the advantages of this patch. Do you have some compelling
performance figures or something?

We can only put numa_distance_cnt on one node, so for the cpus of other nodes to access it should
spend more time. I have not tested how many can be improved yet.

I will try to get some data next week.

Will

.