| Message ID | 20210325002835.216118-5-mike.kravetz@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | make hugetlb put_page safe for all calling contexts | expand |
On Wed 24-03-21 17:28:31, Mike Kravetz wrote: > The new remove_hugetlb_page() routine is designed to remove a hugetlb > page from hugetlbfs processing. It will remove the page from the active > or free list, update global counters and set the compound page > destructor to NULL so that PageHuge() will return false for the 'page'. > After this call, the 'page' can be treated as a normal compound page or > a collection of base size pages. > > remove_hugetlb_page is to be called with the hugetlb_lock held. > > Creating this routine and separating functionality is in preparation for > restructuring code to reduce lock hold times. Call out that this is not intended to introduce any functional change. > > Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Thanks! > --- > mm/hugetlb.c | 70 +++++++++++++++++++++++++++++++++------------------- > 1 file changed, 45 insertions(+), 25 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 404b0b1c5258..3938ec086b5c 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -1327,6 +1327,46 @@ static inline void destroy_compound_gigantic_page(struct page *page, > unsigned int order) { } > #endif > > +/* > + * Remove hugetlb page from lists, and update dtor so that page appears > + * as just a compound page. A reference is held on the page. > + * NOTE: hugetlb specific page flags stored in page->private are not > + * automatically cleared. These flags may be used in routines > + * which operate on the resulting compound page. > + * > + * Must be called with hugetlb lock held. > + */ > +static void remove_hugetlb_page(struct hstate *h, struct page *page, > + bool adjust_surplus) > +{ > + int nid = page_to_nid(page); > + > + if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) > + return; > + > + list_del(&page->lru); > + > + if (HPageFreed(page)) { > + h->free_huge_pages--; > + h->free_huge_pages_node[nid]--; > + ClearHPageFreed(page); > + } > + if (adjust_surplus) { > + h->surplus_huge_pages--; > + h->surplus_huge_pages_node[nid]--; > + } > + > + VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); > + VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); > + > + ClearHPageTemporary(page); > + set_page_refcounted(page); > + set_compound_page_dtor(page, NULL_COMPOUND_DTOR); > + > + h->nr_huge_pages--; > + h->nr_huge_pages_node[nid]--; > +} > + > static void update_and_free_page(struct hstate *h, struct page *page) > { > int i; > @@ -1335,8 +1375,6 @@ static void update_and_free_page(struct hstate *h, struct page *page) > if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) > return; > > - h->nr_huge_pages--; > - h->nr_huge_pages_node[page_to_nid(page)]--; > for (i = 0; i < pages_per_huge_page(h); > i++, subpage = mem_map_next(subpage, page, i)) { > subpage->flags &= ~(1 << PG_locked | 1 << PG_error | > @@ -1344,10 +1382,6 @@ static void update_and_free_page(struct hstate *h, struct page *page) > 1 << PG_active | 1 << PG_private | > 1 << PG_writeback); > } > - VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); > - VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); > - set_compound_page_dtor(page, NULL_COMPOUND_DTOR); > - set_page_refcounted(page); > if (hstate_is_gigantic(h)) { > destroy_compound_gigantic_page(page, huge_page_order(h)); > free_gigantic_page(page, huge_page_order(h)); > @@ -1415,15 +1449,12 @@ static void __free_huge_page(struct page *page) > h->resv_huge_pages++; > > if (HPageTemporary(page)) { > - list_del(&page->lru); > - ClearHPageTemporary(page); > + remove_hugetlb_page(h, page, false); > update_and_free_page(h, page); > } else if (h->surplus_huge_pages_node[nid]) { > /* remove the page from active list */ > - list_del(&page->lru); > + remove_hugetlb_page(h, page, true); > update_and_free_page(h, page); > - h->surplus_huge_pages--; > - h->surplus_huge_pages_node[nid]--; > } else { > arch_clear_hugepage_flags(page); > enqueue_huge_page(h, page); > @@ -1708,13 +1739,7 @@ static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, > struct page *page = > list_entry(h->hugepage_freelists[node].next, > struct page, lru); > - list_del(&page->lru); > - h->free_huge_pages--; > - h->free_huge_pages_node[node]--; > - if (acct_surplus) { > - h->surplus_huge_pages--; > - h->surplus_huge_pages_node[node]--; > - } > + remove_hugetlb_page(h, page, acct_surplus); > update_and_free_page(h, page); > ret = 1; > break; > @@ -1752,7 +1777,6 @@ int dissolve_free_huge_page(struct page *page) > if (!page_count(page)) { > struct page *head = compound_head(page); > struct hstate *h = page_hstate(head); > - int nid = page_to_nid(head); > if (h->free_huge_pages - h->resv_huge_pages == 0) > goto out; > > @@ -1783,9 +1807,7 @@ int dissolve_free_huge_page(struct page *page) > SetPageHWPoison(page); > ClearPageHWPoison(head); > } > - list_del(&head->lru); > - h->free_huge_pages--; > - h->free_huge_pages_node[nid]--; > + remove_hugetlb_page(h, page, false); > h->max_huge_pages--; > update_and_free_page(h, head); > rc = 0; > @@ -2553,10 +2575,8 @@ static void try_to_free_low(struct hstate *h, unsigned long count, > return; > if (PageHighMem(page)) > continue; > - list_del(&page->lru); > + remove_hugetlb_page(h, page, false); > update_and_free_page(h, page); > - h->free_huge_pages--; > - h->free_huge_pages_node[page_to_nid(page)]--; > } > } > } > -- > 2.30.2 >
On 2021/3/25 8:28, Mike Kravetz wrote: > The new remove_hugetlb_page() routine is designed to remove a hugetlb > page from hugetlbfs processing. It will remove the page from the active > or free list, update global counters and set the compound page > destructor to NULL so that PageHuge() will return false for the 'page'. > After this call, the 'page' can be treated as a normal compound page or > a collection of base size pages. > > remove_hugetlb_page is to be called with the hugetlb_lock held. > > Creating this routine and separating functionality is in preparation for > restructuring code to reduce lock hold times. > > Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> > --- > mm/hugetlb.c | 70 +++++++++++++++++++++++++++++++++------------------- > 1 file changed, 45 insertions(+), 25 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 404b0b1c5258..3938ec086b5c 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -1327,6 +1327,46 @@ static inline void destroy_compound_gigantic_page(struct page *page, > unsigned int order) { } > #endif > > +/* > + * Remove hugetlb page from lists, and update dtor so that page appears > + * as just a compound page. A reference is held on the page. > + * NOTE: hugetlb specific page flags stored in page->private are not > + * automatically cleared. These flags may be used in routines > + * which operate on the resulting compound page. It seems HPageFreed and HPageTemporary is cleared. Which hugetlb specific page flags is reserverd here and why? Could you please give a simple example to clarify this in the comment to help understand this NOTE? The code looks good to me. Many thanks! Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> > + * > + * Must be called with hugetlb lock held. > + */ > +static void remove_hugetlb_page(struct hstate *h, struct page *page, > + bool adjust_surplus) > +{ > + int nid = page_to_nid(page); > + > + if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) > + return; > + > + list_del(&page->lru); > + > + if (HPageFreed(page)) { > + h->free_huge_pages--; > + h->free_huge_pages_node[nid]--; > + ClearHPageFreed(page); > + } > + if (adjust_surplus) { > + h->surplus_huge_pages--; > + h->surplus_huge_pages_node[nid]--; > + } > + > + VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); > + VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); > + > + ClearHPageTemporary(page); > + set_page_refcounted(page); > + set_compound_page_dtor(page, NULL_COMPOUND_DTOR); > + > + h->nr_huge_pages--; > + h->nr_huge_pages_node[nid]--; > +} > + > static void update_and_free_page(struct hstate *h, struct page *page) > { > int i; > @@ -1335,8 +1375,6 @@ static void update_and_free_page(struct hstate *h, struct page *page) > if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) > return; > > - h->nr_huge_pages--; > - h->nr_huge_pages_node[page_to_nid(page)]--; > for (i = 0; i < pages_per_huge_page(h); > i++, subpage = mem_map_next(subpage, page, i)) { > subpage->flags &= ~(1 << PG_locked | 1 << PG_error | > @@ -1344,10 +1382,6 @@ static void update_and_free_page(struct hstate *h, struct page *page) > 1 << PG_active | 1 << PG_private | > 1 << PG_writeback); > } > - VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); > - VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); > - set_compound_page_dtor(page, NULL_COMPOUND_DTOR); > - set_page_refcounted(page); > if (hstate_is_gigantic(h)) { > destroy_compound_gigantic_page(page, huge_page_order(h)); > free_gigantic_page(page, huge_page_order(h)); > @@ -1415,15 +1449,12 @@ static void __free_huge_page(struct page *page) > h->resv_huge_pages++; > > if (HPageTemporary(page)) { > - list_del(&page->lru); > - ClearHPageTemporary(page); > + remove_hugetlb_page(h, page, false); > update_and_free_page(h, page); > } else if (h->surplus_huge_pages_node[nid]) { > /* remove the page from active list */ > - list_del(&page->lru); > + remove_hugetlb_page(h, page, true); > update_and_free_page(h, page); > - h->surplus_huge_pages--; > - h->surplus_huge_pages_node[nid]--; > } else { > arch_clear_hugepage_flags(page); > enqueue_huge_page(h, page); > @@ -1708,13 +1739,7 @@ static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, > struct page *page = > list_entry(h->hugepage_freelists[node].next, > struct page, lru); > - list_del(&page->lru); > - h->free_huge_pages--; > - h->free_huge_pages_node[node]--; > - if (acct_surplus) { > - h->surplus_huge_pages--; > - h->surplus_huge_pages_node[node]--; > - } > + remove_hugetlb_page(h, page, acct_surplus); > update_and_free_page(h, page); > ret = 1; > break; > @@ -1752,7 +1777,6 @@ int dissolve_free_huge_page(struct page *page) > if (!page_count(page)) { > struct page *head = compound_head(page); > struct hstate *h = page_hstate(head); > - int nid = page_to_nid(head); > if (h->free_huge_pages - h->resv_huge_pages == 0) > goto out; > > @@ -1783,9 +1807,7 @@ int dissolve_free_huge_page(struct page *page) > SetPageHWPoison(page); > ClearPageHWPoison(head); > } > - list_del(&head->lru); > - h->free_huge_pages--; > - h->free_huge_pages_node[nid]--; > + remove_hugetlb_page(h, page, false); > h->max_huge_pages--; > update_and_free_page(h, head); > rc = 0; > @@ -2553,10 +2575,8 @@ static void try_to_free_low(struct hstate *h, unsigned long count, > return; > if (PageHighMem(page)) > continue; > - list_del(&page->lru); > + remove_hugetlb_page(h, page, false); > update_and_free_page(h, page); > - h->free_huge_pages--; > - h->free_huge_pages_node[page_to_nid(page)]--; > } > } > } >
On 3/25/21 7:10 PM, Miaohe Lin wrote: > On 2021/3/25 8:28, Mike Kravetz wrote: >> The new remove_hugetlb_page() routine is designed to remove a hugetlb >> page from hugetlbfs processing. It will remove the page from the active >> or free list, update global counters and set the compound page >> destructor to NULL so that PageHuge() will return false for the 'page'. >> After this call, the 'page' can be treated as a normal compound page or >> a collection of base size pages. >> >> remove_hugetlb_page is to be called with the hugetlb_lock held. >> >> Creating this routine and separating functionality is in preparation for >> restructuring code to reduce lock hold times. >> >> Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> >> --- >> mm/hugetlb.c | 70 +++++++++++++++++++++++++++++++++------------------- >> 1 file changed, 45 insertions(+), 25 deletions(-) >> >> diff --git a/mm/hugetlb.c b/mm/hugetlb.c >> index 404b0b1c5258..3938ec086b5c 100644 >> --- a/mm/hugetlb.c >> +++ b/mm/hugetlb.c >> @@ -1327,6 +1327,46 @@ static inline void destroy_compound_gigantic_page(struct page *page, >> unsigned int order) { } >> #endif >> >> +/* >> + * Remove hugetlb page from lists, and update dtor so that page appears >> + * as just a compound page. A reference is held on the page. >> + * NOTE: hugetlb specific page flags stored in page->private are not >> + * automatically cleared. These flags may be used in routines >> + * which operate on the resulting compound page. > > It seems HPageFreed and HPageTemporary is cleared. Which hugetlb specific page flags > is reserverd here and why? Could you please give a simple example to clarify > this in the comment to help understand this NOTE? > I will remove that NOTE: in the comment to avoid any confusion. The NOTE was add in the RFC that contained a separate patch to add a flag that tracked huge pages allocated from CMA. That flag needed to remain for subsequent freeing of such pages. This is no longer needed. > The code looks good to me. Many thanks! > Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Thanks,
On 2021/3/27 3:57, Mike Kravetz wrote: > On 3/25/21 7:10 PM, Miaohe Lin wrote: >> On 2021/3/25 8:28, Mike Kravetz wrote: >>> The new remove_hugetlb_page() routine is designed to remove a hugetlb >>> page from hugetlbfs processing. It will remove the page from the active >>> or free list, update global counters and set the compound page >>> destructor to NULL so that PageHuge() will return false for the 'page'. >>> After this call, the 'page' can be treated as a normal compound page or >>> a collection of base size pages. >>> >>> remove_hugetlb_page is to be called with the hugetlb_lock held. >>> >>> Creating this routine and separating functionality is in preparation for >>> restructuring code to reduce lock hold times. >>> >>> Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> >>> --- >>> mm/hugetlb.c | 70 +++++++++++++++++++++++++++++++++------------------- >>> 1 file changed, 45 insertions(+), 25 deletions(-) >>> >>> diff --git a/mm/hugetlb.c b/mm/hugetlb.c >>> index 404b0b1c5258..3938ec086b5c 100644 >>> --- a/mm/hugetlb.c >>> +++ b/mm/hugetlb.c >>> @@ -1327,6 +1327,46 @@ static inline void destroy_compound_gigantic_page(struct page *page, >>> unsigned int order) { } >>> #endif >>> >>> +/* >>> + * Remove hugetlb page from lists, and update dtor so that page appears >>> + * as just a compound page. A reference is held on the page. >>> + * NOTE: hugetlb specific page flags stored in page->private are not >>> + * automatically cleared. These flags may be used in routines >>> + * which operate on the resulting compound page. >> >> It seems HPageFreed and HPageTemporary is cleared. Which hugetlb specific page flags >> is reserverd here and why? Could you please give a simple example to clarify >> this in the comment to help understand this NOTE? >> > > I will remove that NOTE: in the comment to avoid any confusion. > > The NOTE was add in the RFC that contained a separate patch to add a flag > that tracked huge pages allocated from CMA. That flag needed to remain > for subsequent freeing of such pages. This is no longer needed. > Many thanks for explaination. I was confused about that NOTE. :) >> The code looks good to me. Many thanks! >> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> > > Thanks, >
On Thu, Mar 25, 2021 at 8:29 AM Mike Kravetz <mike.kravetz@oracle.com> wrote: > > The new remove_hugetlb_page() routine is designed to remove a hugetlb > page from hugetlbfs processing. It will remove the page from the active > or free list, update global counters and set the compound page > destructor to NULL so that PageHuge() will return false for the 'page'. > After this call, the 'page' can be treated as a normal compound page or > a collection of base size pages. > > remove_hugetlb_page is to be called with the hugetlb_lock held. > > Creating this routine and separating functionality is in preparation for > restructuring code to reduce lock hold times. > > Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Thanks for your effort on this. > --- > mm/hugetlb.c | 70 +++++++++++++++++++++++++++++++++------------------- > 1 file changed, 45 insertions(+), 25 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 404b0b1c5258..3938ec086b5c 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -1327,6 +1327,46 @@ static inline void destroy_compound_gigantic_page(struct page *page, > unsigned int order) { } > #endif > > +/* > + * Remove hugetlb page from lists, and update dtor so that page appears > + * as just a compound page. A reference is held on the page. > + * NOTE: hugetlb specific page flags stored in page->private are not > + * automatically cleared. These flags may be used in routines > + * which operate on the resulting compound page. > + * > + * Must be called with hugetlb lock held. > + */ > +static void remove_hugetlb_page(struct hstate *h, struct page *page, > + bool adjust_surplus) > +{ > + int nid = page_to_nid(page); > + > + if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) > + return; > + > + list_del(&page->lru); > + > + if (HPageFreed(page)) { > + h->free_huge_pages--; > + h->free_huge_pages_node[nid]--; > + ClearHPageFreed(page); > + } > + if (adjust_surplus) { > + h->surplus_huge_pages--; > + h->surplus_huge_pages_node[nid]--; > + } > + > + VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); > + VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); > + > + ClearHPageTemporary(page); > + set_page_refcounted(page); > + set_compound_page_dtor(page, NULL_COMPOUND_DTOR); > + > + h->nr_huge_pages--; > + h->nr_huge_pages_node[nid]--; > +} > + > static void update_and_free_page(struct hstate *h, struct page *page) > { > int i; > @@ -1335,8 +1375,6 @@ static void update_and_free_page(struct hstate *h, struct page *page) > if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) > return; > > - h->nr_huge_pages--; > - h->nr_huge_pages_node[page_to_nid(page)]--; > for (i = 0; i < pages_per_huge_page(h); > i++, subpage = mem_map_next(subpage, page, i)) { > subpage->flags &= ~(1 << PG_locked | 1 << PG_error | > @@ -1344,10 +1382,6 @@ static void update_and_free_page(struct hstate *h, struct page *page) > 1 << PG_active | 1 << PG_private | > 1 << PG_writeback); > } > - VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); > - VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); > - set_compound_page_dtor(page, NULL_COMPOUND_DTOR); > - set_page_refcounted(page); > if (hstate_is_gigantic(h)) { > destroy_compound_gigantic_page(page, huge_page_order(h)); > free_gigantic_page(page, huge_page_order(h)); > @@ -1415,15 +1449,12 @@ static void __free_huge_page(struct page *page) > h->resv_huge_pages++; > > if (HPageTemporary(page)) { > - list_del(&page->lru); > - ClearHPageTemporary(page); > + remove_hugetlb_page(h, page, false); > update_and_free_page(h, page); > } else if (h->surplus_huge_pages_node[nid]) { > /* remove the page from active list */ > - list_del(&page->lru); > + remove_hugetlb_page(h, page, true); > update_and_free_page(h, page); > - h->surplus_huge_pages--; > - h->surplus_huge_pages_node[nid]--; > } else { > arch_clear_hugepage_flags(page); > enqueue_huge_page(h, page); > @@ -1708,13 +1739,7 @@ static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, > struct page *page = > list_entry(h->hugepage_freelists[node].next, > struct page, lru); > - list_del(&page->lru); > - h->free_huge_pages--; > - h->free_huge_pages_node[node]--; > - if (acct_surplus) { > - h->surplus_huge_pages--; > - h->surplus_huge_pages_node[node]--; > - } > + remove_hugetlb_page(h, page, acct_surplus); > update_and_free_page(h, page); > ret = 1; > break; > @@ -1752,7 +1777,6 @@ int dissolve_free_huge_page(struct page *page) > if (!page_count(page)) { > struct page *head = compound_head(page); > struct hstate *h = page_hstate(head); > - int nid = page_to_nid(head); > if (h->free_huge_pages - h->resv_huge_pages == 0) > goto out; > > @@ -1783,9 +1807,7 @@ int dissolve_free_huge_page(struct page *page) > SetPageHWPoison(page); > ClearPageHWPoison(head); > } > - list_del(&head->lru); > - h->free_huge_pages--; > - h->free_huge_pages_node[nid]--; > + remove_hugetlb_page(h, page, false); > h->max_huge_pages--; > update_and_free_page(h, head); > rc = 0; > @@ -2553,10 +2575,8 @@ static void try_to_free_low(struct hstate *h, unsigned long count, > return; > if (PageHighMem(page)) > continue; > - list_del(&page->lru); > + remove_hugetlb_page(h, page, false); > update_and_free_page(h, page); > - h->free_huge_pages--; > - h->free_huge_pages_node[page_to_nid(page)]--; > } > } > } > -- > 2.30.2 >
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 404b0b1c5258..3938ec086b5c 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1327,6 +1327,46 @@ static inline void destroy_compound_gigantic_page(struct page *page, unsigned int order) { } #endif +/* + * Remove hugetlb page from lists, and update dtor so that page appears + * as just a compound page. A reference is held on the page. + * NOTE: hugetlb specific page flags stored in page->private are not + * automatically cleared. These flags may be used in routines + * which operate on the resulting compound page. + * + * Must be called with hugetlb lock held. + */ +static void remove_hugetlb_page(struct hstate *h, struct page *page, + bool adjust_surplus) +{ + int nid = page_to_nid(page); + + if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) + return; + + list_del(&page->lru); + + if (HPageFreed(page)) { + h->free_huge_pages--; + h->free_huge_pages_node[nid]--; + ClearHPageFreed(page); + } + if (adjust_surplus) { + h->surplus_huge_pages--; + h->surplus_huge_pages_node[nid]--; + } + + VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); + VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); + + ClearHPageTemporary(page); + set_page_refcounted(page); + set_compound_page_dtor(page, NULL_COMPOUND_DTOR); + + h->nr_huge_pages--; + h->nr_huge_pages_node[nid]--; +} + static void update_and_free_page(struct hstate *h, struct page *page) { int i; @@ -1335,8 +1375,6 @@ static void update_and_free_page(struct hstate *h, struct page *page) if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) return; - h->nr_huge_pages--; - h->nr_huge_pages_node[page_to_nid(page)]--; for (i = 0; i < pages_per_huge_page(h); i++, subpage = mem_map_next(subpage, page, i)) { subpage->flags &= ~(1 << PG_locked | 1 << PG_error | @@ -1344,10 +1382,6 @@ static void update_and_free_page(struct hstate *h, struct page *page) 1 << PG_active | 1 << PG_private | 1 << PG_writeback); } - VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); - VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); - set_compound_page_dtor(page, NULL_COMPOUND_DTOR); - set_page_refcounted(page); if (hstate_is_gigantic(h)) { destroy_compound_gigantic_page(page, huge_page_order(h)); free_gigantic_page(page, huge_page_order(h)); @@ -1415,15 +1449,12 @@ static void __free_huge_page(struct page *page) h->resv_huge_pages++; if (HPageTemporary(page)) { - list_del(&page->lru); - ClearHPageTemporary(page); + remove_hugetlb_page(h, page, false); update_and_free_page(h, page); } else if (h->surplus_huge_pages_node[nid]) { /* remove the page from active list */ - list_del(&page->lru); + remove_hugetlb_page(h, page, true); update_and_free_page(h, page); - h->surplus_huge_pages--; - h->surplus_huge_pages_node[nid]--; } else { arch_clear_hugepage_flags(page); enqueue_huge_page(h, page); @@ -1708,13 +1739,7 @@ static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, struct page *page = list_entry(h->hugepage_freelists[node].next, struct page, lru); - list_del(&page->lru); - h->free_huge_pages--; - h->free_huge_pages_node[node]--; - if (acct_surplus) { - h->surplus_huge_pages--; - h->surplus_huge_pages_node[node]--; - } + remove_hugetlb_page(h, page, acct_surplus); update_and_free_page(h, page); ret = 1; break; @@ -1752,7 +1777,6 @@ int dissolve_free_huge_page(struct page *page) if (!page_count(page)) { struct page *head = compound_head(page); struct hstate *h = page_hstate(head); - int nid = page_to_nid(head); if (h->free_huge_pages - h->resv_huge_pages == 0) goto out; @@ -1783,9 +1807,7 @@ int dissolve_free_huge_page(struct page *page) SetPageHWPoison(page); ClearPageHWPoison(head); } - list_del(&head->lru); - h->free_huge_pages--; - h->free_huge_pages_node[nid]--; + remove_hugetlb_page(h, page, false); h->max_huge_pages--; update_and_free_page(h, head); rc = 0; @@ -2553,10 +2575,8 @@ static void try_to_free_low(struct hstate *h, unsigned long count, return; if (PageHighMem(page)) continue; - list_del(&page->lru); + remove_hugetlb_page(h, page, false); update_and_free_page(h, page); - h->free_huge_pages--; - h->free_huge_pages_node[page_to_nid(page)]--; } } }
The new remove_hugetlb_page() routine is designed to remove a hugetlb page from hugetlbfs processing. It will remove the page from the active or free list, update global counters and set the compound page destructor to NULL so that PageHuge() will return false for the 'page'. After this call, the 'page' can be treated as a normal compound page or a collection of base size pages. remove_hugetlb_page is to be called with the hugetlb_lock held. Creating this routine and separating functionality is in preparation for restructuring code to reduce lock hold times. Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> --- mm/hugetlb.c | 70 +++++++++++++++++++++++++++++++++------------------- 1 file changed, 45 insertions(+), 25 deletions(-)