[PATCH v12 08/13] mm/hugetlb: Flush work when dissolving a HugeTLB page
flat view
STALE2091d
REVIEWED: 2 (2M)
From: Muchun Song <hidden>
Date: 2021-01-06 14:22:14
Also in:
linux-fsdevel, linux-mm, lkml
Subsystem:
hugetlb subsystem, memory management, the rest · Maintainers:
Muchun Song, Oscar Salvador, Andrew Morton, Linus Torvalds
Revision v12 of 22 in this series; 1 review trailer (1 from subsystem maintainers).
Revisions (22)
- v2 [diff vs current]
- v3 [diff vs current]
- v4 [diff vs current]
- v5 [diff vs current]
- v6 [diff vs current]
- v7 [diff vs current]
- v8 [diff vs current]
- v9 [diff vs current]
- v10 [diff vs current]
- v11 [diff vs current]
- v12 current
- v13 [diff vs current]
- v14 [diff vs current]
- v15 [diff vs current]
- v16 [diff vs current]
- v17 [diff vs current]
- v18 [diff vs current]
- v19 [diff vs current]
- v20 [diff vs current]
- v21 [diff vs current]
- v22 [diff vs current]
- v23 [diff vs current]
We should flush work when dissolving a HugeTLB page to make sure that the HugeTLB page is freed to the buddy allocator. Because the caller of dissolve_free_huge_pages() relies on this guarantee. Signed-off-by: Muchun Song <redacted> Reviewed-by: Oscar Salvador <osalvador@suse.de> --- mm/hugetlb.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 6caaa7e5dd2a..3222bad8b112 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c@@ -1337,6 +1337,12 @@ static void update_hpage_vmemmap_workfn(struct work_struct *work) } static DECLARE_WORK(hpage_update_work, update_hpage_vmemmap_workfn); +static inline void flush_hpage_update_work(struct hstate *h) +{ + if (free_vmemmap_pages_per_hpage(h)) + flush_work(&hpage_update_work); +} + static inline void __update_and_free_page(struct hstate *h, struct page *page) { /* No need to allocate vmemmap pages */
@@ -1887,6 +1893,7 @@ static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, int dissolve_free_huge_page(struct page *page) { int rc = -EBUSY; + struct hstate *h = NULL; /* Not to disrupt normal path by vainly holding hugetlb_lock */ if (!PageHuge(page))
@@ -1900,8 +1907,9 @@ 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); + + h = page_hstate(head); if (h->free_huge_pages - h->resv_huge_pages == 0) goto out;
@@ -1915,6 +1923,14 @@ int dissolve_free_huge_page(struct page *page) } out: spin_unlock(&hugetlb_lock); + + /* + * We should flush work before return to make sure that + * the HugeTLB page is freed to the buddy. + */ + if (!rc && h) + flush_hpage_update_work(h); + return rc; }
--
2.11.0