[PATCH 2/6] mm/hwpoison: don't need to hold compound lock for hugetlbfs page

From: Wanpeng Li
Date: Thu Aug 22 2013 - 05:49:34 EST


compound lock is introduced by commit e9da73d67("thp: compound_lock."),
it is used to serialize put_page against __split_huge_page_refcount().
In addition, transparent hugepages will be splitted in hwpoison handler
and just one subpage will be poisoned. There is unnecessary to hold
compound lock for hugetlbfs page. This patch replace compound_trans_order
by compond_order in the place where the page is hugetlbfs page.

Signed-off-by: Wanpeng Li <liwanp@xxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 2c13aa7..5092e06 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -206,7 +206,7 @@ static int kill_proc(struct task_struct *t, unsigned long addr, int trapno,
#ifdef __ARCH_SI_TRAPNO
si.si_trapno = trapno;
#endif
- si.si_addr_lsb = compound_trans_order(compound_head(page)) + PAGE_SHIFT;
+ si.si_addr_lsb = compound_order(compound_head(page)) + PAGE_SHIFT;

if ((flags & MF_ACTION_REQUIRED) && t == current) {
si.si_code = BUS_MCEERR_AR;
@@ -983,7 +983,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
static void set_page_hwpoison_huge_page(struct page *hpage)
{
int i;
- int nr_pages = 1 << compound_trans_order(hpage);
+ int nr_pages = 1 << compound_order(hpage);
for (i = 0; i < nr_pages; i++)
SetPageHWPoison(hpage + i);
}
@@ -991,7 +991,7 @@ static void set_page_hwpoison_huge_page(struct page *hpage)
static void clear_page_hwpoison_huge_page(struct page *hpage)
{
int i;
- int nr_pages = 1 << compound_trans_order(hpage);
+ int nr_pages = 1 << compound_order(hpage);
for (i = 0; i < nr_pages; i++)
ClearPageHWPoison(hpage + i);
}
@@ -1491,7 +1491,7 @@ static int soft_offline_huge_page(struct page *page, int flags)
} else {
set_page_hwpoison_huge_page(hpage);
dequeue_hwpoisoned_huge_page(hpage);
- atomic_long_add(1 << compound_trans_order(hpage),
+ atomic_long_add(1 << compound_order(hpage),
&num_poisoned_pages);
}
return ret;
@@ -1551,7 +1551,7 @@ int soft_offline_page(struct page *page, int flags)
if (PageHuge(page)) {
set_page_hwpoison_huge_page(hpage);
dequeue_hwpoisoned_huge_page(hpage);
- atomic_long_add(1 << compound_trans_order(hpage),
+ atomic_long_add(1 << compound_order(hpage),
&num_poisoned_pages);
} else {
SetPageHWPoison(page);
--
1.8.1.2

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