2022-09-17 02:35:19

by haoxin

[permalink] [raw]
Subject: [PATCH V3] 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]>
Changes from v2
https://lore.kernel.org/linux-mm/[email protected]/
- Convert is_resv_equal_free() to available_huge_pages()
---
mm/hugetlb.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 5ea0b1b0d1ab..21d7f2361696 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);
@@ -2105,7 +2109,7 @@ 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;

/*
@@ -2315,7 +2319,7 @@ 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 00:18:10

by Mike Kravetz

[permalink] [raw]
Subject: Re: [PATCH V3] mm/hugetlb: add available_huge_pages() func

On 09/17/22 09:15, 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.

Thanks, I think the code looks a little better with this change.

>
> Signed-off-by: Xin Hao <[email protected]>
> Changes from v2
> https://lore.kernel.org/linux-mm/[email protected]/
> - Convert is_resv_equal_free() to available_huge_pages()

I believe the above 'Changes from v2' information should be below the marker
'---' as it will not be included in the changelog.

> ---
> mm/hugetlb.c | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)

The changes look fine,

Reviewed-by: Mike Kravetz <[email protected]>
--
Mike Kravetz

>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 5ea0b1b0d1ab..21d7f2361696 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);
> @@ -2105,7 +2109,7 @@ 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;
>
> /*
> @@ -2315,7 +2319,7 @@ 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 02:08:08

by haoxin

[permalink] [raw]
Subject: Re: [PATCH V3] mm/hugetlb: add available_huge_pages() func


在 2022/9/20 上午7:58, Mike Kravetz 写道:
> On 09/17/22 09:15, 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.
> Thanks, I think the code looks a little better with this change.
>
>> Signed-off-by: Xin Hao <[email protected]>
>> Changes from v2
>> https://lore.kernel.org/linux-mm/[email protected]/
>> - Convert is_resv_equal_free() to available_huge_pages()
> I believe the above 'Changes from v2' information should be below the marker
> '---' as it will not be included in the changelog.
Ok, i will remove the changelog in the next patch.
>
>> ---
>> mm/hugetlb.c | 14 +++++++++-----
>> 1 file changed, 9 insertions(+), 5 deletions(-)
> The changes look fine,
>
> Reviewed-by: Mike Kravetz <[email protected]>

2022-09-20 03:40:04

by Oscar Salvador

[permalink] [raw]
Subject: Re: [PATCH V3] mm/hugetlb: add available_huge_pages() func

On Sat, Sep 17, 2022 at 09:15:28AM +0800, 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: Oscar Salvador <[email protected]>


--
Oscar Salvador
SUSE Labs