diff options
| author | Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> | 2010-09-08 10:19:36 +0900 |
|---|---|---|
| committer | Andi Kleen <ak@linux.intel.com> | 2010-10-08 09:32:45 +0200 |
| commit | 6de2b1aab94355482bd2accdc115666509667458 (patch) | |
| tree | 630a88dd5afe2c49a428179770140b22bbc9d7da | |
| parent | 290408d4a25002f099efeee7b6a5778d431154d6 (diff) | |
HWPOISON, hugetlb: add free check to dequeue_hwpoison_huge_page()
This check is necessary to avoid race between dequeue and allocation,
which can cause a free hugepage to be dequeued twice and get kernel unstable.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
| -rw-r--r-- | include/linux/hugetlb.h | 4 | ||||
| -rw-r--r-- | mm/hugetlb.c | 29 | ||||
| -rw-r--r-- | mm/memory-failure.c | 6 |
3 files changed, 31 insertions, 8 deletions
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 9e51f77d44c..796f30e0080 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -43,7 +43,7 @@ int hugetlb_reserve_pages(struct inode *inode, long from, long to, struct vm_area_struct *vma, int acctflags); void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed); -void __isolate_hwpoisoned_huge_page(struct page *page); +int dequeue_hwpoisoned_huge_page(struct page *page); void copy_huge_page(struct page *dst, struct page *src); extern unsigned long hugepages_treat_as_movable; @@ -102,7 +102,7 @@ static inline void hugetlb_report_meminfo(struct seq_file *m) #define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) ({BUG(); 0; }) #define hugetlb_fault(mm, vma, addr, flags) ({ BUG(); 0; }) #define huge_pte_offset(mm, address) 0 -#define __isolate_hwpoisoned_huge_page(page) 0 +#define dequeue_hwpoisoned_huge_page(page) 0 static inline void copy_huge_page(struct page *dst, struct page *src) { } diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 0fa9de8361b..deb7bebefe6 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2955,18 +2955,39 @@ void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) hugetlb_acct_memory(h, -(chg - freed)); } +/* Should be called in hugetlb_lock */ +static int is_hugepage_on_freelist(struct page *hpage) +{ + struct page *page; + struct page *tmp; + struct hstate *h = page_hstate(hpage); + int nid = page_to_nid(hpage); + + list_for_each_entry_safe(page, tmp, &h->hugepage_freelists[nid], lru) + if (page == hpage) + return 1; + return 0; +} + +#ifdef CONFIG_MEMORY_FAILURE /* * This function is called from memory failure code. * Assume the caller holds page lock of the head page. */ -void __isolate_hwpoisoned_huge_page(struct page *hpage) +int dequeue_hwpoisoned_huge_page(struct page *hpage) { struct hstate *h = page_hstate(hpage); int nid = page_to_nid(hpage); + int ret = -EBUSY; spin_lock(&hugetlb_lock); - list_del(&hpage->lru); - h->free_huge_pages--; - h->free_huge_pages_node[nid]--; + if (is_hugepage_on_freelist(hpage)) { + list_del(&hpage->lru); + h->free_huge_pages--; + h->free_huge_pages_node[nid]--; + ret = 0; + } spin_unlock(&hugetlb_lock); + return ret; } +#endif diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 757f6b0accf..5c7158a1159 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -698,6 +698,7 @@ static int me_swapcache_clean(struct page *p, unsigned long pfn) */ static int me_huge_page(struct page *p, unsigned long pfn) { + int res = 0; struct page *hpage = compound_head(p); /* * We can safely recover from error on free or reserved (i.e. @@ -710,8 +711,9 @@ static int me_huge_page(struct page *p, unsigned long pfn) * so there is no race between isolation and mapping/unmapping. */ if (!(page_mapping(hpage) || PageAnon(hpage))) { - __isolate_hwpoisoned_huge_page(hpage); - return RECOVERED; + res = dequeue_hwpoisoned_huge_page(hpage); + if (!res) + return RECOVERED; } return DELAYED; } |