From: Muchun Song <songmuchun@bytedance.com>
To: mike.kravetz@oracle.com, akpm@linux-foundation.org
Cc: hillf.zj@alibaba-inc.com, n-horiguchi@ah.jp.nec.com,
ak@linux.intel.com, yongjun_wei@trendmicro.com.cn,
mhocko@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Muchun Song <songmuchun@bytedance.com>
Subject: [PATCH 4/6] mm: hugetlb: add return -EAGAIN for dissolve_free_huge_page
Date: Mon, 4 Jan 2021 14:58:41 +0800 [thread overview]
Message-ID: <20210104065843.5658-4-songmuchun@bytedance.com> (raw)
In-Reply-To: <20210104065843.5658-1-songmuchun@bytedance.com>
When dissolve_free_huge_page() races with __free_huge_page(), we can
do a retry. Because the race window is small.
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
mm/hugetlb.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 72608008f8b4..db00ae375d2a 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1763,10 +1763,11 @@ static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed,
* nothing for in-use hugepages and non-hugepages.
* This function returns values like below:
*
- * -EBUSY: failed to dissolved free hugepages or the hugepage is in-use
- * (allocated or reserved.)
- * 0: successfully dissolved free hugepages or the page is not a
- * hugepage (considered as already dissolved)
+ * -EAGAIN: race with __free_huge_page() and can do a retry
+ * -EBUSY: failed to dissolved free hugepages or the hugepage is in-use
+ * (allocated or reserved.)
+ * 0: successfully dissolved free hugepages or the page is not a
+ * hugepage (considered as already dissolved)
*/
int dissolve_free_huge_page(struct page *page)
{
@@ -1815,8 +1816,10 @@ int dissolve_free_huge_page(struct page *page)
* We should make sure that the page is already on the free list
* when it is dissolved.
*/
- if (unlikely(!PageHugeFreed(head)))
+ if (unlikely(!PageHugeFreed(head))) {
+ rc = -EAGAIN;
goto out;
+ }
/*
* Move PageHWPoison flag from head page to the raw error page,
@@ -1857,7 +1860,10 @@ int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn)
for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << minimum_order) {
page = pfn_to_page(pfn);
+retry:
rc = dissolve_free_huge_page(page);
+ if (rc == -EAGAIN)
+ goto retry;
if (rc)
break;
}
--
2.11.0
next prev parent reply other threads:[~2021-01-04 7:04 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-04 6:58 [PATCH 1/6] mm: migrate: do not migrate HugeTLB page whose refcount is one Muchun Song
2021-01-04 6:58 ` [PATCH 2/6] hugetlbfs: fix cannot migrate the fallocated HugeTLB page Muchun Song
2021-01-04 22:38 ` Mike Kravetz
2021-01-05 2:44 ` [External] " Muchun Song
2021-01-05 22:27 ` Mike Kravetz
2021-01-06 2:57 ` Muchun Song
2021-01-04 6:58 ` [PATCH 3/6] mm: hugetlb: fix a race between freeing and dissolving the page Muchun Song
2021-01-05 0:00 ` Mike Kravetz
2021-01-05 2:55 ` [External] " Muchun Song
2021-01-05 23:22 ` Mike Kravetz
2021-01-06 6:05 ` Muchun Song
2021-01-05 6:12 ` Muchun Song
2021-01-04 6:58 ` Muchun Song [this message]
2021-01-05 1:32 ` [PATCH 4/6] mm: hugetlb: add return -EAGAIN for dissolve_free_huge_page Mike Kravetz
2021-01-05 3:14 ` [External] " Muchun Song
2021-01-05 3:46 ` Muchun Song
2021-01-06 0:07 ` Mike Kravetz
2021-01-05 6:37 ` HORIGUCHI NAOYA(堀口 直也)
2021-01-05 7:10 ` [External] " Muchun Song
2021-01-05 7:30 ` HORIGUCHI NAOYA(堀口 直也)
2021-01-04 6:58 ` [PATCH 5/6] mm: hugetlb: fix a race between isolating and freeing page Muchun Song
2021-01-05 1:42 ` Mike Kravetz
2021-01-04 6:58 ` [PATCH 6/6] mm: hugetlb: remove VM_BUG_ON_PAGE from page_huge_active Muchun Song
2021-01-05 1:50 ` Mike Kravetz
2021-01-04 22:17 ` [PATCH 1/6] mm: migrate: do not migrate HugeTLB page whose refcount is one Mike Kravetz
2021-01-05 16:58 ` David Hildenbrand
2021-01-05 18:04 ` Yang Shi
2021-01-05 18:05 ` David Hildenbrand
2021-01-05 18:04 ` Yang Shi
2021-01-06 16:11 ` Michal Hocko
2021-01-06 16:12 ` Michal Hocko
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