2022-09-20 02:42:22

by haoxin

Subject: [PATCH v4] mm/hugetlb: add available_huge_pages() func

In hugetlb.c file, there are several places to compare the values of
'h->free_huge_pages' and 'h->resv_huge_pages', it looks a bit messy, so
there add a new available_huge_pages() func to do these.

Signed-off-by: Xin Hao <[email protected]>
Reviewed-by: Mike Kravetz <[email protected]>
---
mm/hugetlb.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 9b8526d27c29..99dc961d131a 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1191,6 +1191,11 @@ static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask,
return NULL;
}

+static unsigned long available_huge_pages(struct hstate *h)
+{
+ return h->free_huge_pages - h->resv_huge_pages;
+}
+
static struct page *dequeue_huge_page_vma(struct hstate *h,
struct vm_area_struct *vma,
unsigned long address, int avoid_reserve,
@@ -1207,12 +1212,11 @@ static struct page *dequeue_huge_page_vma(struct hstate *h,
* have no page reserves. This check ensures that reservations are
* not "stolen". The child may still get SIGKILLed
*/
- if (!vma_has_reserves(vma, chg) &&
- h->free_huge_pages - h->resv_huge_pages == 0)
+ if (!vma_has_reserves(vma, chg) && !available_huge_pages(h))
goto err;

/* If reserves cannot be used, ensure enough pages are in the pool */
- if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0)
+ if (avoid_reserve && !available_huge_pages(h))
goto err;

gfp_mask = htlb_alloc_mask(h);
@@ -2124,7 +2128,7 @@ int dissolve_free_huge_page(struct page *page)
if (!page_count(page)) {
struct page *head = compound_head(page);
struct hstate *h = page_hstate(head);
- if (h->free_huge_pages - h->resv_huge_pages == 0)
+ if (!available_huge_pages(h))
goto out;

/*
@@ -2311,7 +2315,7 @@ struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid,
nodemask_t *nmask, gfp_t gfp_mask)
{
spin_lock_irq(&hugetlb_lock);
- if (h->free_huge_pages - h->resv_huge_pages > 0) {
+ if (available_huge_pages(h)) {
struct page *page;

page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask);
--
2.31.0

2022-09-20 03:37:54

by Muchun Song

Subject: Re: [PATCH v4] mm/hugetlb: add available_huge_pages() func

> On Sep 20, 2022, at 09:51, Xin Hao <[email protected]> wrote:
>
> In hugetlb.c file, there are several places to compare the values of
> 'h->free_huge_pages' and 'h->resv_huge_pages', it looks a bit messy, so
> there add a new available_huge_pages() func to do these.
>
> Signed-off-by: Xin Hao <[email protected]>
> Reviewed-by: Mike Kravetz <[email protected]>

Reviewed-by: Muchun Song <[email protected]>

Thanks.

2022-09-20 12:18:11

by David Hildenbrand

Subject: Re: [PATCH v4] mm/hugetlb: add available_huge_pages() func

On 20.09.22 03:51, Xin Hao wrote:
> In hugetlb.c file, there are several places to compare the values of
> 'h->free_huge_pages' and 'h->resv_huge_pages', it looks a bit messy, so
> there add a new available_huge_pages() func to do these.
>
> Signed-off-by: Xin Hao <[email protected]>
> Reviewed-by: Mike Kravetz <[email protected]>
> ---

Reviewed-by: David Hildenbrand <[email protected]>

--
Thanks,

David / dhildenb