2020-10-29 20:42:23

by Vanshidhar Konda

[permalink] [raw]
Subject: [PATCH v2] arm64: NUMA: Kconfig: Increase NODES_SHIFT to 4

The current arm64 default config limits max NUMA nodes available on
system to 4 (NODES_SHIFT = 2). Today's arm64 systems can reach or
exceed 16 NUMA nodes. To accomodate current hardware and to fit
NODES_SHIFT within page flags on arm64, increase NODES_SHIFT to 4.

Discussion on v1 of the patch:
https://lkml.org/lkml/2020/10/20/767

Signed-off-by: Vanshidhar Konda <[email protected]>
---
arch/arm64/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index f858c352f72a..cffcc677011f 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -982,7 +982,7 @@ config NUMA
config NODES_SHIFT
int "Maximum NUMA Nodes (as a power of 2)"
range 1 10
- default "2"
+ default "4"
depends on NEED_MULTIPLE_NODES
help
Specify the maximum number of NUMA Nodes available on the target
--
2.28.0


2020-10-30 10:29:10

by Catalin Marinas

[permalink] [raw]
Subject: Re: [PATCH v2] arm64: NUMA: Kconfig: Increase NODES_SHIFT to 4

On Thu, Oct 29, 2020 at 01:37:52PM -0700, Vanshidhar Konda wrote:
> The current arm64 default config limits max NUMA nodes available on
> system to 4 (NODES_SHIFT = 2). Today's arm64 systems can reach or
> exceed 16 NUMA nodes. To accomodate current hardware and to fit
> NODES_SHIFT within page flags on arm64, increase NODES_SHIFT to 4.
>
> Discussion on v1 of the patch:
> https://lkml.org/lkml/2020/10/20/767

Better use a stable link to refer to the past discussion:

Link: https://lore.kernel.org/r/[email protected]

> Signed-off-by: Vanshidhar Konda <[email protected]>
> ---
> arch/arm64/Kconfig | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index f858c352f72a..cffcc677011f 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -982,7 +982,7 @@ config NUMA
> config NODES_SHIFT
> int "Maximum NUMA Nodes (as a power of 2)"
> range 1 10
> - default "2"
> + default "4"
> depends on NEED_MULTIPLE_NODES
> help
> Specify the maximum number of NUMA Nodes available on the target

Acked-by: Catalin Marinas <[email protected]>