diff mbox

[v4,8/8] mm: rmap: Use correct helper when poisoning hugepages

Message ID 20170524115409.31309-9-punit.agrawal@arm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Punit Agrawal May 24, 2017, 11:54 a.m. UTC 
Using set_pte_at() does not do the right thing when putting down
HWPOISON swap entries for hugepages on architectures that support
contiguous ptes.

Fix this problem by using set_huge_swap_pte_at() which was introduced to
fix exactly this problem.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Acked-by: Steve Capper <steve.capper@arm.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
---
 mm/rmap.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

Comments

kernel test robot May 24, 2017, 7:20 p.m. UTC | #1 
Hi Punit,

[auto build test ERROR on linus/master]
[also build test ERROR on v4.12-rc2 next-20170524]
[cannot apply to mmotm/master]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Punit-Agrawal/Support-for-contiguous-pte-hugepages/20170524-221905
config: x86_64-kexec (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All errors (new ones prefixed by >>):

   mm/rmap.c: In function 'try_to_unmap_one':
>> mm/rmap.c:1386:5: error: implicit declaration of function 'set_huge_swap_pte_at' [-Werror=implicit-function-declaration]
        set_huge_swap_pte_at(mm, address,
        ^~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors

vim +/set_huge_swap_pte_at +1386 mm/rmap.c

  1380	
  1381			if (PageHWPoison(page) && !(flags & TTU_IGNORE_HWPOISON)) {
  1382				pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
  1383				if (PageHuge(page)) {
  1384					int nr = 1 << compound_order(page);
  1385					hugetlb_count_sub(nr, mm);
> 1386					set_huge_swap_pte_at(mm, address,
  1387							     pvmw.pte, pteval,
  1388							     vma_mmu_pagesize(vma));
  1389				} else {

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
Punit Agrawal May 25, 2017, 5:22 p.m. UTC | #2 
kbuild test robot <lkp@intel.com> writes:

> Hi Punit,
>
> [auto build test ERROR on linus/master]
> [also build test ERROR on v4.12-rc2 next-20170524]
> [cannot apply to mmotm/master]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
>
> url:    https://github.com/0day-ci/linux/commits/Punit-Agrawal/Support-for-contiguous-pte-hugepages/20170524-221905
> config: x86_64-kexec (attached as .config)
> compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
> reproduce:
>         # save the attached .config to linux build tree
>         make ARCH=x86_64 
>
> All errors (new ones prefixed by >>):
>
>    mm/rmap.c: In function 'try_to_unmap_one':
>>> mm/rmap.c:1386:5: error: implicit declaration of function 'set_huge_swap_pte_at' [-Werror=implicit-function-declaration]
>         set_huge_swap_pte_at(mm, address,
>         ^~~~~~~~~~~~~~~~~~~~
>    cc1: some warnings being treated as errors
>
> vim +/set_huge_swap_pte_at +1386 mm/rmap.c
>
>   1380	
>   1381			if (PageHWPoison(page) && !(flags & TTU_IGNORE_HWPOISON)) {
>   1382				pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
>   1383				if (PageHuge(page)) {
>   1384					int nr = 1 << compound_order(page);
>   1385					hugetlb_count_sub(nr, mm);
>> 1386					set_huge_swap_pte_at(mm, address,
>   1387							     pvmw.pte, pteval,
>   1388							     vma_mmu_pagesize(vma));
>   1389				} else {
>

Thanks for the report. The build failure is caused due to missing
function definition for set_huge_swap_pte_at() when CONFIG_HUGETLB_PAGE
is disabled. I've posted an update to Patch 7 where the function is
introduced to fix this issue.

> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
diff mbox

Patch

diff --git a/mm/rmap.c b/mm/rmap.c
index d405f0e0ee96..feb2352aa95f 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1379,15 +1379,18 @@  static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 		update_hiwater_rss(mm);
 
 		if (PageHWPoison(page) && !(flags & TTU_IGNORE_HWPOISON)) {
+			pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
 			if (PageHuge(page)) {
 				int nr = 1 << compound_order(page);
 				hugetlb_count_sub(nr, mm);
+				set_huge_swap_pte_at(mm, address,
+						     pvmw.pte, pteval,
+						     vma_mmu_pagesize(vma));
 			} else {
 				dec_mm_counter(mm, mm_counter(page));
+				set_pte_at(mm, address, pvmw.pte, pteval);
 			}
 
-			pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
-			set_pte_at(mm, address, pvmw.pte, pteval);
 		} else if (pte_unused(pteval)) {
 			/*
 			 * The guest indicated that the page content is of no