Re: [PATCH] memory hotplug: run lru_add_drain_all() on each cpu

KOSAKI Motohiro
2008-12-08T14:30:40Z

>> Lee, Could you read this thread and explain why you add ifdef CONFIG_UNEVICTABLE_LRU?
>> I am not sure about that Dave's proposal is safe change. (but I guess he is right)
>
> I added that back in Patch 17/25 "Mlocked Pages are
> non-reclaimable" [before nonreclaimable became unevictable". I did this
> because "lru_add_drain_all()" was only used by numa code prior to this,
> and was under #ifdef CONFIG_NUMA". I called lru_add_drain_all() from
> __mlock_vma_pages_range() [since removed] and I wanted the
> nonreclaimable/unevictable mlocked pages feature to be independent of
> numa. So, I had to ensure that we defined the function for
> nonreclaimable/unevictable lru as well as numa.
>
> Now it appears that hotplug and memcg also depend on
> lru_add_drain_all(), so making it depend on 'SMP looks reasonable to me.

Thanks a lot.

I'll make that patch.