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Groups > linux.kernel > #1478497
| From | "Huang, Ying" <ying.huang@intel.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH -v3 09/10] mm, THP, swap: Support to split THP in swap cache |
| Date | 2016-09-07 18:50 +0200 |
| Message-ID | <seOcW-2cL-39@gated-at.bofh.it> (permalink) |
| References | <seOcV-2cL-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Huang Ying <ying.huang@intel.com>
This patch enhanced the split_huge_page_to_list() to work properly for
the THP (Transparent Huge Page) in the swap cache during swapping out.
This is used for delaying splitting the THP during swapping out. Where
for a THP to be swapped out, we will allocate a swap cluster, add the
THP into the swap cache, then split the THP. The page lock will be held
during this process. So in the code path other than swapping out, if
the THP need to be split, the PageSwapCache(THP) will be always false.
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
---
mm/huge_memory.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 3be5abe..3bb4976 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1834,7 +1834,7 @@ static void __split_huge_page_tail(struct page *head, int tail,
* atomic_set() here would be safe on all archs (and not only on x86),
* it's safer to use atomic_inc()/atomic_add().
*/
- if (PageAnon(head)) {
+ if (PageAnon(head) && !PageSwapCache(head)) {
page_ref_inc(page_tail);
} else {
/* Additional pin to radix tree */
@@ -1845,6 +1845,7 @@ static void __split_huge_page_tail(struct page *head, int tail,
page_tail->flags |= (head->flags &
((1L << PG_referenced) |
(1L << PG_swapbacked) |
+ (1L << PG_swapcache) |
(1L << PG_mlocked) |
(1L << PG_uptodate) |
(1L << PG_active) |
@@ -1907,7 +1908,11 @@ static void __split_huge_page(struct page *page, struct list_head *list,
ClearPageCompound(head);
/* See comment in __split_huge_page_tail() */
if (PageAnon(head)) {
- page_ref_inc(head);
+ /* Additional pin to radix tree of swap cache */
+ if (PageSwapCache(head))
+ page_ref_add(head, 2);
+ else
+ page_ref_inc(head);
} else {
/* Additional pin to radix tree */
page_ref_add(head, 2);
@@ -2019,10 +2024,12 @@ int page_trans_huge_mapcount(struct page *page, int *total_mapcount)
/* Racy check whether the huge page can be split */
bool can_split_huge_page(struct page *page)
{
- int extra_pins = 0;
+ int extra_pins;
/* Additional pins from radix tree */
- if (!PageAnon(page))
+ if (PageAnon(page))
+ extra_pins = PageSwapCache(page) ? HPAGE_PMD_NR : 0;
+ else
extra_pins = HPAGE_PMD_NR;
return total_mapcount(page) == page_count(page) - extra_pins - 1;
}
@@ -2075,7 +2082,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
ret = -EBUSY;
goto out;
}
- extra_pins = 0;
+ extra_pins = PageSwapCache(head) ? HPAGE_PMD_NR : 0;
mapping = NULL;
anon_vma_lock_write(anon_vma);
} else {
--
2.8.1
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[PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
[PATCH -v3 02/10] mm, memcg: Add swap_cgroup_iter iterator "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
[PATCH -v3 08/10] mm, THP: Add can_split_huge_page() "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
Re: [PATCH -v3 08/10] mm, THP: Add can_split_huge_page() "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-09-08 13:20 +0200
Re: [PATCH -v3 08/10] mm, THP: Add can_split_huge_page() "Huang\, Ying" <ying.huang@intel.com> - 2016-09-08 19:10 +0200
[PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP size on x86_64 "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
Re: [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP size on x86_64 Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2016-09-08 10:30 +0200
Re: [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP size on x86_64 Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2016-09-08 11:20 +0200
Re: [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP size on x86_64 "Huang\, Ying" <ying.huang@intel.com> - 2016-09-08 20:10 +0200
Re: [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP size on x86_64 "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-09-08 13:10 +0200
Re: [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP size on x86_64 "Huang\, Ying" <ying.huang@intel.com> - 2016-09-08 19:40 +0200
Re: [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP size on x86_64 "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-09-08 13:10 +0200
Re: [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP size on x86_64 "Huang\, Ying" <ying.huang@intel.com> - 2016-09-08 19:30 +0200
[PATCH -v3 05/10] mm, THP, swap: Add get_huge_swap_page() "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
Re: [PATCH -v3 05/10] mm, THP, swap: Add get_huge_swap_page() "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-09-08 13:20 +0200
Re: [PATCH -v3 05/10] mm, THP, swap: Add get_huge_swap_page() "Huang\, Ying" <ying.huang@intel.com> - 2016-09-08 19:30 +0200
[PATCH -v3 09/10] mm, THP, swap: Support to split THP in swap cache "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
[PATCH -v3 06/10] mm, THP, swap: Support to clear SWAP_HAS_CACHE for huge page "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
[PATCH -v3 03/10] mm, memcg: Support to charge/uncharge multiple swap entries "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
Re: [PATCH -v3 03/10] mm, memcg: Support to charge/uncharge multiple swap entries Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2016-09-08 10:30 +0200
Re: [PATCH -v3 03/10] mm, memcg: Support to charge/uncharge multiple swap entries "Huang\, Ying" <ying.huang@intel.com> - 2016-09-08 20:20 +0200
Re: [PATCH -v3 03/10] mm, memcg: Support to charge/uncharge multiple swap entries Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2016-09-08 10:40 +0200
[PATCH -v3 04/10] mm, THP, swap: Add swap cluster allocate/free functions "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
Re: [PATCH -v3 04/10] mm, THP, swap: Add swap cluster allocate/free functions Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2016-09-08 10:40 +0200
Re: [PATCH -v3 04/10] mm, THP, swap: Add swap cluster allocate/free functions "Huang\, Ying" <ying.huang@intel.com> - 2016-09-08 20:20 +0200
Re: [PATCH -v3 04/10] mm, THP, swap: Add swap cluster allocate/free functions Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2016-09-08 11:00 +0200
[PATCH -v3 07/10] mm, THP, swap: Support to add/delete THP to/from swap cache "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
Re: [PATCH -v3 07/10] mm, THP, swap: Support to add/delete THP to/from swap cache Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2016-09-08 11:10 +0200
Re: [PATCH -v3 07/10] mm, THP, swap: Support to add/delete THP to/from swap cache "Huang\, Ying" <ying.huang@intel.com> - 2016-09-08 20:20 +0200
Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out Minchan Kim <minchan@kernel.org> - 2016-09-09 07:50 +0200
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