Re: [PATCH] Hugepages should be accounted as unevictable pages.

KOSAKI Motohiro
2009-06-23T03:25:55Z

> Looking at the output of /proc/meminfo, a user might get confused in thinking
> that there are zero unevictable pages, though, in reality their can be
> hugepages which are inherently unevictable.
>
> Though hugepages are not handled by the unevictable lru framework, they are
> infact unevictable in nature and global statistics counter should reflect that.
>
> For instance, I have allocated 20 huge pages on my system, meminfo shows this
>
> Unevictable: 0 kB
> Mlocked: 0 kB
> HugePages_Total: 20
> HugePages_Free: 20
> HugePages_Rsvd: 0
> HugePages_Surp: 0
>
> After the patch:
>
> Unevictable: 81920 kB
> Mlocked: 0 kB
> HugePages_Total: 20
> HugePages_Free: 20
> HugePages_Rsvd: 0
> HugePages_Surp: 0

At first, We should clarify the spec of unevictable.
Currently, Unevictable field mean the number of pages in unevictable-lru
and hugepage never insert any lru.

I think this patch will change this rule.