Re: [PATCH] pagemap: fix wrong KPF_THP on slab pages

From: David Rientjes
Date: Tue Sep 25 2012 - 20:21:10 EST


On Tue, 25 Sep 2012, Naoya Horiguchi wrote:

> KPF_THP can be set on non-huge compound pages like slab pages, because
> PageTransCompound only sees PG_head and PG_tail. Obviously this is a bug
> and breaks user space applications which look for thp via /proc/kpageflags.
> Currently thp is constructed only on anonymous pages, so this patch makes
> KPF_THP be set when both of PageAnon and PageTransCompound are true.
>
> Changelog in v2:
> - add a comment in code
>
> Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>

Wouldn't PageTransCompound(page) && !PageHuge(page) && !PageSlab(page) be
better for a future extension of thp support?
--
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/