Change alloc_huge_page_nodemask() to alloc_hugetlb_folio_nodemask() and
alloc_migrate_huge_page() to alloc_migrate_hugetlb_folio(). Both functions
now return a folio rather than a page.
Signed-off-by: Sidhartha Kumar <[email protected]>
---
include/linux/hugetlb.h | 6 +++---
mm/hugetlb.c | 18 +++++++++---------
mm/migrate.c | 5 ++++-
3 files changed, 16 insertions(+), 13 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 482929b2d044..a853c13d8308 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -680,7 +680,7 @@ struct huge_bootmem_page {
int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list);
struct page *alloc_huge_page(struct vm_area_struct *vma,
unsigned long addr, int avoid_reserve);
-struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid,
+struct folio *alloc_hugetlb_folio_nodemask(struct hstate *h, int preferred_nid,
nodemask_t *nmask, gfp_t gfp_mask);
struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma,
unsigned long address);
@@ -1001,8 +1001,8 @@ static inline struct page *alloc_huge_page(struct vm_area_struct *vma,
return NULL;
}
-static inline struct page *
-alloc_huge_page_nodemask(struct hstate *h, int preferred_nid,
+static inline struct folio *
+alloc_hugetlb_folio_nodemask(struct hstate *h, int preferred_nid,
nodemask_t *nmask, gfp_t gfp_mask)
{
return NULL;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 640ca4eaccf2..0db01718d1c3 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2278,7 +2278,7 @@ static struct folio *alloc_surplus_hugetlb_folio(struct hstate *h,
return folio;
}
-static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask,
+static struct folio *alloc_migrate_hugetlb_folio(struct hstate *h, gfp_t gfp_mask,
int nid, nodemask_t *nmask)
{
struct folio *folio;
@@ -2298,7 +2298,7 @@ static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask,
*/
folio_set_hugetlb_temporary(folio);
- return &folio->page;
+ return folio;
}
/*
@@ -2331,8 +2331,8 @@ struct folio *alloc_buddy_hugetlb_folio_with_mpol(struct hstate *h,
return folio;
}
-/* page migration callback function */
-struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid,
+/* folio migration callback function */
+struct folio *alloc_hugetlb_folio_nodemask(struct hstate *h, int preferred_nid,
nodemask_t *nmask, gfp_t gfp_mask)
{
spin_lock_irq(&hugetlb_lock);
@@ -2343,12 +2343,12 @@ struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid,
preferred_nid, nmask);
if (folio) {
spin_unlock_irq(&hugetlb_lock);
- return &folio->page;
+ return folio;
}
}
spin_unlock_irq(&hugetlb_lock);
- return alloc_migrate_huge_page(h, gfp_mask, preferred_nid, nmask);
+ return alloc_migrate_hugetlb_folio(h, gfp_mask, preferred_nid, nmask);
}
/* mempolicy aware migration callback */
@@ -2357,16 +2357,16 @@ struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma,
{
struct mempolicy *mpol;
nodemask_t *nodemask;
- struct page *page;
+ struct folio *folio;
gfp_t gfp_mask;
int node;
gfp_mask = htlb_alloc_mask(h);
node = huge_node(vma, address, gfp_mask, &mpol, &nodemask);
- page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask);
+ folio = alloc_hugetlb_folio_nodemask(h, node, nodemask, gfp_mask);
mpol_cond_put(mpol);
- return page;
+ return &folio->page;
}
/*
diff --git a/mm/migrate.c b/mm/migrate.c
index 6932b3d5a9dd..fab706b78be1 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1622,6 +1622,7 @@ struct page *alloc_migration_target(struct page *page, unsigned long private)
struct migration_target_control *mtc;
gfp_t gfp_mask;
unsigned int order = 0;
+ struct folio *hugetlb_folio = NULL;
struct folio *new_folio = NULL;
int nid;
int zidx;
@@ -1636,7 +1637,9 @@ struct page *alloc_migration_target(struct page *page, unsigned long private)
struct hstate *h = folio_hstate(folio);
gfp_mask = htlb_modify_alloc_mask(h, gfp_mask);
- return alloc_huge_page_nodemask(h, nid, mtc->nmask, gfp_mask);
+ hugetlb_folio = alloc_hugetlb_folio_nodemask(h, nid,
+ mtc->nmask, gfp_mask);
+ return &hugetlb_folio->page;
}
if (folio_test_large(folio)) {
--
2.39.0
On 01/03/23 13:13, Sidhartha Kumar wrote:
> Change alloc_huge_page_nodemask() to alloc_hugetlb_folio_nodemask() and
> alloc_migrate_huge_page() to alloc_migrate_hugetlb_folio(). Both functions
> now return a folio rather than a page.
> /* mempolicy aware migration callback */
> @@ -2357,16 +2357,16 @@ struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma,
> {
> struct mempolicy *mpol;
> nodemask_t *nodemask;
> - struct page *page;
> + struct folio *folio;
> gfp_t gfp_mask;
> int node;
>
> gfp_mask = htlb_alloc_mask(h);
> node = huge_node(vma, address, gfp_mask, &mpol, &nodemask);
> - page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask);
> + folio = alloc_hugetlb_folio_nodemask(h, node, nodemask, gfp_mask);
> mpol_cond_put(mpol);
>
> - return page;
> + return &folio->page;
Is it possible that folio could be NULL here and cause addressing exception?
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 6932b3d5a9dd..fab706b78be1 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1622,6 +1622,7 @@ struct page *alloc_migration_target(struct page *page, unsigned long private)
> struct migration_target_control *mtc;
> gfp_t gfp_mask;
> unsigned int order = 0;
> + struct folio *hugetlb_folio = NULL;
> struct folio *new_folio = NULL;
> int nid;
> int zidx;
> @@ -1636,7 +1637,9 @@ struct page *alloc_migration_target(struct page *page, unsigned long private)
> struct hstate *h = folio_hstate(folio);
>
> gfp_mask = htlb_modify_alloc_mask(h, gfp_mask);
> - return alloc_huge_page_nodemask(h, nid, mtc->nmask, gfp_mask);
> + hugetlb_folio = alloc_hugetlb_folio_nodemask(h, nid,
> + mtc->nmask, gfp_mask);
> + return &hugetlb_folio->page;
and, here as well?
--
Mike Kravetz
> }
>
> if (folio_test_large(folio)) {
> --
> 2.39.0
>
On 1/6/23 6:54 PM, Mike Kravetz wrote:
> On 01/03/23 13:13, Sidhartha Kumar wrote:
>> Change alloc_huge_page_nodemask() to alloc_hugetlb_folio_nodemask() and
>> alloc_migrate_huge_page() to alloc_migrate_hugetlb_folio(). Both functions
>> now return a folio rather than a page.
>
>> /* mempolicy aware migration callback */
>> @@ -2357,16 +2357,16 @@ struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma,
>> {
>> struct mempolicy *mpol;
>> nodemask_t *nodemask;
>> - struct page *page;
>> + struct folio *folio;
>> gfp_t gfp_mask;
>> int node;
>>
>> gfp_mask = htlb_alloc_mask(h);
>> node = huge_node(vma, address, gfp_mask, &mpol, &nodemask);
>> - page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask);
>> + folio = alloc_hugetlb_folio_nodemask(h, node, nodemask, gfp_mask);
>> mpol_cond_put(mpol);
>>
>> - return page;
>> + return &folio->page;
>
> Is it possible that folio could be NULL here and cause addressing exception?
>
>> diff --git a/mm/migrate.c b/mm/migrate.c
>> index 6932b3d5a9dd..fab706b78be1 100644
>> --- a/mm/migrate.c
>> +++ b/mm/migrate.c
>> @@ -1622,6 +1622,7 @@ struct page *alloc_migration_target(struct page *page, unsigned long private)
>> struct migration_target_control *mtc;
>> gfp_t gfp_mask;
>> unsigned int order = 0;
>> + struct folio *hugetlb_folio = NULL;
>> struct folio *new_folio = NULL;
>> int nid;
>> int zidx;
>> @@ -1636,7 +1637,9 @@ struct page *alloc_migration_target(struct page *page, unsigned long private)
>> struct hstate *h = folio_hstate(folio);
>>
>> gfp_mask = htlb_modify_alloc_mask(h, gfp_mask);
>> - return alloc_huge_page_nodemask(h, nid, mtc->nmask, gfp_mask);
>> + hugetlb_folio = alloc_hugetlb_folio_nodemask(h, nid,
>> + mtc->nmask, gfp_mask);
>> + return &hugetlb_folio->page;
>
> and, here as well?
Hi Mike,
It is possible that the folio could be null but I believe these
instances would not cause an addressing exception because as described
in [1], &folio->page is safe even if the folio is NULL as the page
offset is at 0.
[1] https://lore.kernel.org/lkml/[email protected]/T/
On 01/09/23 10:26, Sidhartha Kumar wrote:
> On 1/6/23 6:54 PM, Mike Kravetz wrote:
> > On 01/03/23 13:13, Sidhartha Kumar wrote:
> > > Change alloc_huge_page_nodemask() to alloc_hugetlb_folio_nodemask() and
> > > alloc_migrate_huge_page() to alloc_migrate_hugetlb_folio(). Both functions
> > > now return a folio rather than a page.
> >
> > > /* mempolicy aware migration callback */
> > > @@ -2357,16 +2357,16 @@ struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma,
> > > {
> > > struct mempolicy *mpol;
> > > nodemask_t *nodemask;
> > > - struct page *page;
> > > + struct folio *folio;
> > > gfp_t gfp_mask;
> > > int node;
> > > gfp_mask = htlb_alloc_mask(h);
> > > node = huge_node(vma, address, gfp_mask, &mpol, &nodemask);
> > > - page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask);
> > > + folio = alloc_hugetlb_folio_nodemask(h, node, nodemask, gfp_mask);
> > > mpol_cond_put(mpol);
> > > - return page;
> > > + return &folio->page;
> >
> > Is it possible that folio could be NULL here and cause addressing exception?
> >
> > > diff --git a/mm/migrate.c b/mm/migrate.c
> > > index 6932b3d5a9dd..fab706b78be1 100644
> > > --- a/mm/migrate.c
> > > +++ b/mm/migrate.c
> > > @@ -1622,6 +1622,7 @@ struct page *alloc_migration_target(struct page *page, unsigned long private)
> > > struct migration_target_control *mtc;
> > > gfp_t gfp_mask;
> > > unsigned int order = 0;
> > > + struct folio *hugetlb_folio = NULL;
> > > struct folio *new_folio = NULL;
> > > int nid;
> > > int zidx;
> > > @@ -1636,7 +1637,9 @@ struct page *alloc_migration_target(struct page *page, unsigned long private)
> > > struct hstate *h = folio_hstate(folio);
> > > gfp_mask = htlb_modify_alloc_mask(h, gfp_mask);
> > > - return alloc_huge_page_nodemask(h, nid, mtc->nmask, gfp_mask);
> > > + hugetlb_folio = alloc_hugetlb_folio_nodemask(h, nid,
> > > + mtc->nmask, gfp_mask);
> > > + return &hugetlb_folio->page;
> >
> > and, here as well?
>
> Hi Mike,
>
> It is possible that the folio could be null but I believe these instances
> would not cause an addressing exception because as described in [1],
> &folio->page is safe even if the folio is NULL as the page offset is at 0.
>
>
> [1] https://lore.kernel.org/lkml/[email protected]/T/
Thanks!
I did not follow that thread and did not look closely as to whether
&folio->page was safe with folio == NULL.
I must say that it is going to take me some time to not pause and think
when coming upon &folio->page. Perhaps that is good.
Reviewed-by: Mike Kravetz <[email protected]>
--
Mike Kravetz