Re: [BUG] hugetlb MAP_PRIVATE mapping vs /dev/zero

From: William Lee Irwin III
Date: Thu Jul 01 2004 - 23:23:26 EST


On Fri, Jul 02, 2004 at 01:49:37PM +1000, David Gibson wrote:
>> Duh, sorry, misread the sense of the VM_SHARED test in the zeromap
>> code.

On Fri, Jul 02, 2004 at 02:12:15PM +1000, David Gibson wrote:
> On second thoughts, though, I think logically it should be fixed in
> both places. For now forcing VM_SHARED in the hugetlbfs code is
> sufficient, but if we ever allow (real) MAP_PRIVATE hugepage mappings
> (by implementing hugepage COW, for example), then the zeromap code
> will need fixing.
> Conceptually it's not so much the fact that the hugepage memory is
> shared which is tripping up zeromap as the fact that it isn't mapped
> in the normal way.
> Of course, one could argue that the whole zeromap idea is just too
> damn clever for its own good...

Better that there should be a zeromap_hugepage_range() than pollution
of random pseudodrivers.


-- wli
-
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/