On 5/17/20 6:20 PM, js1304@xxxxxxxxx wrote:
> From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
>
> Currently, page allocation functions for migration requires some arguments.
> More worse, in the following patch, more argument will be needed to unify
> the similar functions. To simplify them, in this patch, unified data
> structure that controls allocation behaviour is introduced.
As a followup to Roman's question and your answer about adding a suffix/prefix
to the new structure. It 'may' be a bit confusing as alloc_context is already
defined and *ac is passsed around for page allocations. Perhaps, this new
structure could somehow have migrate in the name as it is all about allocating
migrate targets?
>
> For clean-up, function declarations are re-ordered.
>
> Note that, gfp_mask handling on alloc_huge_page_(node|nodemask) is
> slightly changed, from ASSIGN to OR. It's safe since caller of these
> functions doesn't pass extra gfp_mask except htlb_alloc_mask().
>
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Patch makes sense.
> diff --git a/mm/migrate.c b/mm/migrate.c
> index a298a8c..94d2386 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1526,10 +1526,15 @@ struct page *new_page_nodemask(struct page *page,
> unsigned int order = 0;
> struct page *new_page = NULL;
>
> - if (PageHuge(page))
> - return alloc_huge_page_nodemask(
> - page_hstate(compound_head(page)),
> - preferred_nid, nodemask);
> + if (PageHuge(page)) {
> + struct hstate *h = page_hstate(page);
I assume the removal of compound_head(page) was intentional? Just asking
because PageHuge will look at head page while page_hstate will not. So,
if passed a non-head page things could go bad.
--
Mike Kravetz
