Re: [PATCH v2] mm/mempolicy: track page allocations per mempolicy

["Vlastimil Babka (SUSE)" <vbabka@kernel.org>]

On 3/17/26 07:44, Huang, Ying wrote:
> "JP Kobryn (Meta)" <jp.kobryn@linux.dev> writes:
> 
>>>>
>>>> It's an interesting thought. Looking into these existing counters more,
>>>> the in-kernel direct node allocations, which don't fall under any
>>>> mempolicy, are also included in these stats. One good example might be
>>>> include/linux/skbuff.h, where __dev_alloc_pages() calls
>>>> alloc_pages_node_noprof(NUMA_NO_NODE, ...) which eventually reaches
>>>> zone_statistics() and increments the stats.
>>> IIUC, the default memory policy is used here, that is, MPOL_LOCAL.
>>
>> I'm not seeing that. zone_statistics() is eventually reached.
>> alloc_pages_mpol() is not.
> 
> Yes.  The page isn't allocated through alloc_pages_mpol().  For example,
> if we want to allocate pages for the kernel instead of user space
> applications.  However, IMHO, the equivalent memory policy is
> MPOL_LOCAL, that is, allocate from local node firstly, then fallback to
> other nodes.  I don't think that alloc_pages_mpol() is so special.

Agree, it's equivalent to MPOL_LOCAL.

> ---
> Best Regards,
> Huang, Ying