* Gerald Schaefer <gerald.schae...@de.ibm.com> wrote:
> On Sun, 28 Oct 2012 14:10:14 +0100
> Ingo Molnar <mi...@kernel.org> wrote:
>
> >
> > There's a related problem on s390: other THP implementations
> > have pmd_mknotpresent() while s390 not, resulting in:
> >
> > mm/huge_memory.c:1543:2: error: implicit declaration of function
> > 'pmd_mknotpresent'
> >
> > The (untested!) patch below adds the s390 version of this
> > method.
> >
> > Gerald, Martin, did I get the S390 details right?
>
> The upstream thp patches for s390 fixed that by adding pmdp_invalidate() and
> replacing the pmd_mknotpresent() in mm/huge_memory.c, see git commit 46dcde73.
> The pmdp_invalidate() is already included linux-next, so it should be ok to
> just change mm/huge_memory.c similar to upstream:
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index f1c2679..842b6df 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -1537,8 +1537,7 @@ static int __split_huge_page_map(struct page *page,
> * complete. The ptl also protects against concurrent faults due to
> * making the pmd not-present.
> */
> - set_pmd_at(mm, address, pmd, pmd_mknotpresent(*pmd));
> - flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
> + pmdp_invalidate(vma, address, pmd);
> pmd_populate(mm, pmd, pgtable);
> ret = 1;
>
> With this, s390 does not need a pmd_mknotpresent(), and using
> set_pmd_at(..., pmd_mknotpresent()) would be wrong on s390
> anyway because we need a flushing operation to change a valid
> pmd.
Ok, great - so to me it seems that once the two trees are merged
there's no extra change needed for s390 - so I dropped the
patch.
Thanks,
Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
