Re: linux-next: Tree for Nov 27 (mm stuff)

Vladimir Davydov
2015-11-27T10:16:57Z

On Fri, Nov 27, 2015 at 06:17:39PM +0900, Sergey Senozhatsky wrote:
> Cc Vladimir, Kirill, Andrew
>
> On (11/27/15 18:10), Sergey Senozhatsky wrote:
> > On (11/26/15 23:04), Randy Dunlap wrote:
> > >
> > > on i386:
> > >
> > > mm/built-in.o: In function `page_referenced_one':
> > > rmap.c:(.text+0x362a2): undefined reference to `pmdp_clear_flush_young'
> > > mm/built-in.o: In function `page_idle_clear_pte_refs_one':
> > > page_idle.c:(.text+0x4b2b8): undefined reference to `pmdp_test_and_clear_young'
> > >
> >
> > Hello,
> >
> > https://lkml.org/lkml/2015/11/24/160
> >
> > corresponding patch mm-add-page_check_address_transhuge-helper-fix.patch added
> > to -mm tree.
> >
>
> my bad, it's in -next already.

Sigh, this fails for me too :-( Kirill was right that this hack might
not always work.

So, we still need to check explicitly if CONFIG_TRANSPARENT_HUGEPAGE is
enabled whenever we use page_check_address_transhuge, as Kirill proposed
initially. The patch below does the trick. The previous "fix" is still
useful though, because it reduces the size of kernels compiled w/o
tranparent huge page feature.

Andrew, could you please merge this patch too?

Sorry for all the trouble.

Thanks,
Vladimir
---
diff --git a/mm/page_idle.c b/mm/page_idle.c
index 374931f..aa7ca61 100644
--- a/mm/page_idle.c
+++ b/mm/page_idle.c
@@ -66,7 +66,7 @@ static int page_idle_clear_pte_refs_one(struct page *page,
if (pte) {
referenced = ptep_clear_young_notify(vma, addr, pte);
pte_unmap(pte);
- } else
+ } else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
referenced = pmdp_clear_young_notify(vma, addr, pmd);

spin_unlock(ptl);
diff --git a/mm/rmap.c b/mm/rmap.c
index 6f37126..3286d49 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -931,7 +931,7 @@ static int page_referenced_one(struct page *page, struct vm_area_struct *vma,
referenced++;
}
pte_unmap(pte);
- } else {
+ } else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
if (pmdp_clear_flush_young_notify(vma, address, pmd))
referenced++;
}