| Message ID | 20220916064127.1904-1-xhao@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [V2] mm/hugetlb: add is_resv_equal_free() func | expand |
On Fri, 16 Sep 2022 14:41:27 +0800 Xin Hao <xhao@linux.alibaba.com> 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 is_resv_equal_free() func to do these. > > ... > > --- 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 inline bool is_resv_equal_free(struct hstate *h) I'm not sure that's a well chosen name. A better name would reflect the *meaning* of free_huge_pages being equal to resv_huge_pages. Maybe something like reserves_exhausted()? This would all be clearer if we'd bothered to document the fields of struct hstate :( > +{ > + return (h->free_huge_pages - h->resv_huge_pages == 0) ? true : false; return h->free_huge_pages == h->resv_huge_pages; > +}
On 09/16/22 13:12, Andrew Morton wrote: > On Fri, 16 Sep 2022 14:41:27 +0800 Xin Hao <xhao@linux.alibaba.com> 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 is_resv_equal_free() func to do these. > > > > ... > > > > --- 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 inline bool is_resv_equal_free(struct hstate *h) > > I'm not sure that's a well chosen name. A better name would reflect > the *meaning* of free_huge_pages being equal to resv_huge_pages. Maybe > something like reserves_exhausted()? How about calling it free_non_reserved_huge_pages() and returning the actual value (h->free_huge_pages - h->resv_huge_pages)? Perhaps available_huge_pages()? It could then be used in at least one other place - if (h->free_huge_pages - h->resv_huge_pages > 0) > This would all be clearer if we'd bothered to document the fields of > struct hstate :( Agree, and discussed elsewhwere some may even be able to be eliminated. I can add that to my todo list.
在 2022/9/17 上午5:09, Mike Kravetz 写道: > On 09/16/22 13:12, Andrew Morton wrote: >> On Fri, 16 Sep 2022 14:41:27 +0800 Xin Hao <xhao@linux.alibaba.com> 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 is_resv_equal_free() func to do these. >>> >>> ... >>> >>> --- 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 inline bool is_resv_equal_free(struct hstate *h) >> I'm not sure that's a well chosen name. A better name would reflect >> the *meaning* of free_huge_pages being equal to resv_huge_pages. Maybe >> something like reserves_exhausted()? > How about calling it free_non_reserved_huge_pages() and returning the actual > value (h->free_huge_pages - h->resv_huge_pages)? > > Perhaps available_huge_pages()? Ok, I am going to use available_huge_pages() in the patch v3, thanks. > It could then be used in at least one other place > - if (h->free_huge_pages - h->resv_huge_pages > 0) > >> This would all be clearer if we'd bothered to document the fields of >> struct hstate :( > Agree, and discussed elsewhwere some may even be able to be eliminated. I can > add that to my todo list.
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 66496fc424f4..db6f63fb083f 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 inline bool is_resv_equal_free(struct hstate *h) +{ + return (h->free_huge_pages - h->resv_huge_pages == 0) ? true : false; +} + 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) && is_resv_equal_free(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 && is_resv_equal_free(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 (is_resv_equal_free(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 (!is_resv_equal_free(h)) { struct page *page; page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask);
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 is_resv_equal_free() func to do these. Signed-off-by: Xin Hao <xhao@linux.alibaba.com> --- mm/hugetlb.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) -- 2.31.0