Re: [PATCH] mm/mempolicy: count MPOL_WEIGHTED_INTERLEAVE to "interleave_hit"

[Hyeonggon Yoo <hyeonggon.yoo@sk.com>]

On 2024-12-27 6:57 AM, Honggyu Kim wrote:
> The fa3bea4e1f82 introduced MPOL_WEIGHTED_INTERLEAVE but it missed
> adding its counter to "interleave_hit" of numastat, which is located at
> /sys/devices/system/node/nodeN/ directory.
> 
> It'd be better to add weighted interleving counter info to the existing
> "interleave_hit" instead of introducing a new counter
> "weighted_interleave_hit".
> 
> Fixes: fa3bea4e1f82 ("mm/mempolicy: introduce MPOL_WEIGHTED_INTERLEAVE for weighted interleaving")
> Cc: Gregory Price <gourry@gourry.net>
> Cc: Andi Kleen <ak@linux.intel.com>
> Signed-off-by: Honggyu Kim <honggyu.kim@sk.com>
> ---
>   mm/mempolicy.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 04f35659717a..162407fbf2bc 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -2268,7 +2268,8 @@ struct page *alloc_pages_mpol_noprof(gfp_t gfp, unsigned int order,
>   
>   	page = __alloc_pages_noprof(gfp, order, nid, nodemask);
>   
> -	if (unlikely(pol->mode == MPOL_INTERLEAVE) && page) {
> +	if (unlikely(pol->mode == MPOL_INTERLEAVE ||
> +		     pol->mode == MPOL_WEIGHTED_INTERLEAVE) && page) {
>   		/* skip NUMA_INTERLEAVE_HIT update if numa stats is disabled */
>   		if (static_branch_likely(&vm_numa_stat_key) &&
>   		    page_to_nid(page) == nid) {
> 
> base-commit: 4bbf9020becbfd8fc2c3da790855b7042fad455b

[+Cc Andrew]

Looks good to me,
Reviewed-by: Hyeonggon Yoo <hyeonggon.yoo@sk.com>

We discovered that interleave_hit is not correctly accounted
while testing MPOL_WEIGHTED_INTERLEAVE on libnuma and this patch
fixes the issue.

Tested-by: Yunjeong Mun <yunjeong.mun@sk.com>

For reference:
https://github.com/numactl/numactl/pull/238#issuecomment-2563532910

--
Hyeonggon