Re: [PATCH 8/8] prepare to remove /proc/sys/vm/hugepages_treat_as_movable

[Aneesh Kumar K.V]

Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> writes:


>> 
>> Considering that we have architectures that won't support migrating
>> explicit hugepages with this patch series, is it ok to use
>> GFP_HIGHUSER_MOVABLE for hugepage allocation ?
>
> Originally this parameter was introduced to make hugepage pool on ZONE_MOVABLE.
> The benefit is that we can extend the hugepage pool more easily,
> because external fragmentation less likely happens than other zone type
> by rearranging fragmented pages with page migration/reclaim.
>
> So I think using ZONE_MOVABLE for hugepage allocation by default makes sense
> even on the architectures which don't support hugepage migration.

But allocating hugepages from ZONE_MOVABLE means we have pages in that
zone which we can't migrate. Doesn't that impact other features like
hotplug ?


-aneesh

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/