Re: [PATCH -V6 06/14] hugetlb: Simplify migrate_huge_page

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

On Thu, May 24, 2012 at 02:35:05PM -0700, David Rientjes wrote:
> On Mon, 16 Apr 2012, Aneesh Kumar K.V wrote:
> 
> > diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> > index 97cc273..1f092db 100644
> > --- a/mm/memory-failure.c
> > +++ b/mm/memory-failure.c
> > @@ -1414,7 +1414,6 @@ static int soft_offline_huge_page(struct page *page, int flags)
> >  	int ret;
> >  	unsigned long pfn = page_to_pfn(page);
> >  	struct page *hpage = compound_head(page);
> > -	LIST_HEAD(pagelist);
> >  
> >  	ret = get_any_page(page, pfn, flags);
> >  	if (ret < 0)
> > @@ -1429,19 +1428,11 @@ static int soft_offline_huge_page(struct page *page, int flags)
> >  	}
> >  
> >  	/* Keep page count to indicate a given hugepage is isolated. */
> > -
> > -	list_add(&hpage->lru, &pagelist);
> > -	ret = migrate_huge_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0,
> > -				true);
> > +	ret = migrate_huge_page(page, new_page, MPOL_MF_MOVE_ALL, 0, true);
> 
> Was this tested?  Shouldn't this be migrate_huge_page(compound_head(page), 
> ...)?
> 

I tested this using madvise, but by not using tail pages. How about the below diff ?

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 4a45098..53a1495 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1428,8 +1428,8 @@ static int soft_offline_huge_page(struct page *page, int flags)
 	}
 
 	/* Keep page count to indicate a given hugepage is isolated. */
-	ret = migrate_huge_page(page, new_page, MPOL_MF_MOVE_ALL, 0, true);
-	put_page(page);
+	ret = migrate_huge_page(hpage, new_page, MPOL_MF_MOVE_ALL, 0, true);
+	put_page(hpage);
 	if (ret) {
 		pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
 			pfn, ret, page->flags);