From: Joonsoo Kim <[email protected]>
It's not good practice to modify user input. Instead of using it to
build correct gfp_mask for APIs, this patch introduces another gfp_mask
field, __gfp_mask, for internal usage.
Signed-off-by: Joonsoo Kim <[email protected]>
---
mm/hugetlb.c | 19 ++++++++++---------
mm/internal.h | 2 ++
2 files changed, 12 insertions(+), 9 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index e465582..4757e72 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1068,15 +1068,15 @@ static struct page *dequeue_huge_page_nodemask(struct hstate *h,
struct zoneref *z;
int node = NUMA_NO_NODE;
- zonelist = node_zonelist(ac->nid, ac->gfp_mask);
+ zonelist = node_zonelist(ac->nid, ac->__gfp_mask);
retry_cpuset:
cpuset_mems_cookie = read_mems_allowed_begin();
for_each_zone_zonelist_nodemask(zone, z, zonelist,
- gfp_zone(ac->gfp_mask), ac->nmask) {
+ gfp_zone(ac->__gfp_mask), ac->nmask) {
struct page *page;
- if (!cpuset_zone_allowed(zone, ac->gfp_mask))
+ if (!cpuset_zone_allowed(zone, ac->__gfp_mask))
continue;
/*
* no need to ask again on the same node. Pool is node rather than
@@ -1127,8 +1127,8 @@ static struct page *dequeue_huge_page_vma(struct hstate *h,
if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0)
goto err;
- ac.gfp_mask = htlb_alloc_mask(h);
- ac.nid = huge_node(vma, address, ac.gfp_mask, &mpol, &ac.nmask);
+ ac.__gfp_mask = htlb_alloc_mask(h);
+ ac.nid = huge_node(vma, address, ac.__gfp_mask, &mpol, &ac.nmask);
page = dequeue_huge_page_nodemask(h, &ac);
if (page && !avoid_reserve && vma_has_reserves(vma, chg)) {
@@ -1951,7 +1951,7 @@ static struct page *alloc_migrate_huge_page(struct hstate *h,
if (hstate_is_gigantic(h))
return NULL;
- page = alloc_fresh_huge_page(h, ac->gfp_mask,
+ page = alloc_fresh_huge_page(h, ac->__gfp_mask,
ac->nid, ac->nmask, NULL);
if (!page)
return NULL;
@@ -1989,9 +1989,10 @@ struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h,
struct page *alloc_huge_page_nodemask(struct hstate *h,
struct alloc_control *ac)
{
- ac->gfp_mask |= htlb_alloc_mask(h);
+ ac->__gfp_mask = htlb_alloc_mask(h);
+ ac->__gfp_mask |= ac->gfp_mask;
if (ac->nid == NUMA_NO_NODE)
- ac->gfp_mask &= ~__GFP_THISNODE;
+ ac->__gfp_mask &= ~__GFP_THISNODE;
spin_lock(&hugetlb_lock);
if (h->free_huge_pages - h->resv_huge_pages > 0) {
@@ -2010,7 +2011,7 @@ struct page *alloc_huge_page_nodemask(struct hstate *h,
* will not come from CMA area
*/
if (ac->skip_cma)
- ac->gfp_mask &= ~__GFP_MOVABLE;
+ ac->__gfp_mask &= ~__GFP_MOVABLE;
return alloc_migrate_huge_page(h, ac);
}
diff --git a/mm/internal.h b/mm/internal.h
index 159cfd6..2dc0268 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -619,6 +619,8 @@ struct alloc_control {
nodemask_t *nmask;
gfp_t gfp_mask;
bool skip_cma;
+
+ gfp_t __gfp_mask; /* Used internally in API implementation */
};
#endif /* __MM_INTERNAL_H */
--
2.7.4
On Wed 27-05-20 15:44:58, Joonsoo Kim wrote:
> From: Joonsoo Kim <[email protected]>
>
> It's not good practice to modify user input. Instead of using it to
> build correct gfp_mask for APIs, this patch introduces another gfp_mask
> field, __gfp_mask, for internal usage.
Ugh, this is really ugly. It is just hugetlb to add __GFP_THISNODE as a
special case. This is an ugly hack but I do not think we want to work
around it by yet another hack. Moreover it seems that the __GFP_THISNODE
might be not needed anymore as pointed out in a reply to earlier patch.
> Signed-off-by: Joonsoo Kim <[email protected]>
> ---
> mm/hugetlb.c | 19 ++++++++++---------
> mm/internal.h | 2 ++
> 2 files changed, 12 insertions(+), 9 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index e465582..4757e72 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1068,15 +1068,15 @@ static struct page *dequeue_huge_page_nodemask(struct hstate *h,
> struct zoneref *z;
> int node = NUMA_NO_NODE;
>
> - zonelist = node_zonelist(ac->nid, ac->gfp_mask);
> + zonelist = node_zonelist(ac->nid, ac->__gfp_mask);
>
> retry_cpuset:
> cpuset_mems_cookie = read_mems_allowed_begin();
> for_each_zone_zonelist_nodemask(zone, z, zonelist,
> - gfp_zone(ac->gfp_mask), ac->nmask) {
> + gfp_zone(ac->__gfp_mask), ac->nmask) {
> struct page *page;
>
> - if (!cpuset_zone_allowed(zone, ac->gfp_mask))
> + if (!cpuset_zone_allowed(zone, ac->__gfp_mask))
> continue;
> /*
> * no need to ask again on the same node. Pool is node rather than
> @@ -1127,8 +1127,8 @@ static struct page *dequeue_huge_page_vma(struct hstate *h,
> if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0)
> goto err;
>
> - ac.gfp_mask = htlb_alloc_mask(h);
> - ac.nid = huge_node(vma, address, ac.gfp_mask, &mpol, &ac.nmask);
> + ac.__gfp_mask = htlb_alloc_mask(h);
> + ac.nid = huge_node(vma, address, ac.__gfp_mask, &mpol, &ac.nmask);
>
> page = dequeue_huge_page_nodemask(h, &ac);
> if (page && !avoid_reserve && vma_has_reserves(vma, chg)) {
> @@ -1951,7 +1951,7 @@ static struct page *alloc_migrate_huge_page(struct hstate *h,
> if (hstate_is_gigantic(h))
> return NULL;
>
> - page = alloc_fresh_huge_page(h, ac->gfp_mask,
> + page = alloc_fresh_huge_page(h, ac->__gfp_mask,
> ac->nid, ac->nmask, NULL);
> if (!page)
> return NULL;
> @@ -1989,9 +1989,10 @@ struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h,
> struct page *alloc_huge_page_nodemask(struct hstate *h,
> struct alloc_control *ac)
> {
> - ac->gfp_mask |= htlb_alloc_mask(h);
> + ac->__gfp_mask = htlb_alloc_mask(h);
> + ac->__gfp_mask |= ac->gfp_mask;
> if (ac->nid == NUMA_NO_NODE)
> - ac->gfp_mask &= ~__GFP_THISNODE;
> + ac->__gfp_mask &= ~__GFP_THISNODE;
>
> spin_lock(&hugetlb_lock);
> if (h->free_huge_pages - h->resv_huge_pages > 0) {
> @@ -2010,7 +2011,7 @@ struct page *alloc_huge_page_nodemask(struct hstate *h,
> * will not come from CMA area
> */
> if (ac->skip_cma)
> - ac->gfp_mask &= ~__GFP_MOVABLE;
> + ac->__gfp_mask &= ~__GFP_MOVABLE;
>
> return alloc_migrate_huge_page(h, ac);
> }
> diff --git a/mm/internal.h b/mm/internal.h
> index 159cfd6..2dc0268 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -619,6 +619,8 @@ struct alloc_control {
> nodemask_t *nmask;
> gfp_t gfp_mask;
> bool skip_cma;
> +
> + gfp_t __gfp_mask; /* Used internally in API implementation */
> };
>
> #endif /* __MM_INTERNAL_H */
> --
> 2.7.4
--
Michal Hocko
SUSE Labs
2020년 6월 9일 (화) 오후 10:54, Michal Hocko <[email protected]>님이 작성:
>
> On Wed 27-05-20 15:44:58, Joonsoo Kim wrote:
> > From: Joonsoo Kim <[email protected]>
> >
> > It's not good practice to modify user input. Instead of using it to
> > build correct gfp_mask for APIs, this patch introduces another gfp_mask
> > field, __gfp_mask, for internal usage.
>
> Ugh, this is really ugly. It is just hugetlb to add __GFP_THISNODE as a
> special case. This is an ugly hack but I do not think we want to work
> around it by yet another hack. Moreover it seems that the __GFP_THISNODE
> might be not needed anymore as pointed out in a reply to earlier patch.
If you mean __GFP_THISNODE handling is ugly, as you pointed out,
__GFP_THISNODE handling would be removed in the next version.
If you mean introducing __gfp_mask is ugly, I will try to use a local variable
to keep modified gfp_mask rather than introducing a field in alloc_control.
Thanks.