Subject: + mm-hwpoison-fix-loss-of-pg_dirty-for-errors-on-mlocked-pages.patch added to -mm tree
To: liwanp@xxxxxxxxxxxxxxxxxx,andi@xxxxxxxxxxxxxx,n-horiguchi@xxxxxxxxxxxxx,tony.luck@xxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Mon, 26 Aug 2013 14:42:37 -0700
The patch titled
Subject: mm/hwpoison: fix loss of PG_dirty for errors on mlocked pages
has been added to the -mm tree. Its filename is
mm-hwpoison-fix-loss-of-pg_dirty-for-errors-on-mlocked-pages.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-hwpoison-fix-loss-of-pg_dirty-for-errors-on-mlocked-pages.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-hwpoison-fix-loss-of-pg_dirty-for-errors-on-mlocked-pages.patch
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------------------------------------------------------
From: Wanpeng Li <liwanp@xxxxxxxxxxxxxxxxxx>
Subject: mm/hwpoison: fix loss of PG_dirty for errors on mlocked pages
memory_failure() store the page flag of the error page before doing unmap,
and (only) if the first check with page flags at the time decided the
error page is unknown, it do the second check with the stored page flag
since memory_failure() does unmapping of the error pages before doing
page_action(). This unmapping changes the page state, especially
page_remove_rmap() (called from try_to_unmap_one()) clears PG_mlocked, so
page_action() can't catch mlocked pages after that.
However, memory_failure() can't handle memory errors on dirty mlocked
pages correctly. try_to_unmap_one will move the dirty bit from pte to the
physical page, the second check lose it since it check the stored page
flag. This patch fix it by restore PG_dirty flag to stored page flag if
the page is dirty.
Testcase:
#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <errno.h>
#define PAGES_TO_TEST 2
#define PAGE_SIZE 4096
int main(void)
{
char *mem;
int i;
mem = mmap(NULL, PAGES_TO_TEST * PAGE_SIZE,
PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_LOCKED, 0, 0);
for (i = 0; i < PAGES_TO_TEST; i++)
mem[i * PAGE_SIZE] = 'a';
if (madvise(mem, PAGES_TO_TEST * PAGE_SIZE, MADV_HWPOISON) == -1)
return -1;
return 0;
}
Before patch:
[ 912.839247] Injecting memory failure for page 7dfb8 at 7f6b4e37b000
[ 912.839257] MCE 0x7dfb8: clean mlocked LRU page recovery: Recovered
[ 912.845550] MCE 0x7dfb8: clean mlocked LRU page still referenced by 1 users
[ 912.852586] Injecting memory failure for page 7e6aa at 7f6b4e37c000
[ 912.852594] MCE 0x7e6aa: clean mlocked LRU page recovery: Recovered
[ 912.858936] MCE 0x7e6aa: clean mlocked LRU page still referenced by 1 users
After patch:
[ 163.590225] Injecting memory failure for page 91bc2f at 7f9f5b0e5000
[ 163.590264] MCE 0x91bc2f: dirty mlocked LRU page recovery: Recovered
[ 163.596680] MCE 0x91bc2f: dirty mlocked LRU page still referenced by 1 users
[ 163.603831] Injecting memory failure for page 91cdd3 at 7f9f5b0e6000
[ 163.603852] MCE 0x91cdd3: dirty mlocked LRU page recovery: Recovered
[ 163.610305] MCE 0x91cdd3: dirty mlocked LRU page still referenced by 1 users
Signed-off-by: Wanpeng Li <liwanp@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 3 +++
1 file changed, 3 insertions(+)
diff -puN mm/memory-failure.c~mm-hwpoison-fix-loss-of-pg_dirty-for-errors-on-mlocked-pages mm/memory-failure.c
--- a/mm/memory-failure.c~mm-hwpoison-fix-loss-of-pg_dirty-for-errors-on-mlocked-pages
+++ a/mm/memory-failure.c
@@ -1204,6 +1204,9 @@ int memory_failure(unsigned long pfn, in
for (ps = error_states;; ps++)
if ((p->flags & ps->mask) == ps->res)
break;
+
+ page_flags |= (p->flags & (1UL << PG_dirty));
+
if (!ps->mask)
for (ps = error_states;; ps++)
if ((page_flags & ps->mask) == ps->res)
_
Patches currently in -mm which might be from liwanp@xxxxxxxxxxxxxxxxxx are
mm-zswapc-get-swapper-address_space-by-using-macro.patch
mm-fix-potential-null-pointer-dereference.patch
mm-hugetlb-move-up-the-code-which-check-availability-of-free-huge-page.patch
mm-hugetlb-trivial-commenting-fix.patch
mm-hugetlb-clean-up-alloc_huge_page.patch
mm-hugetlb-fix-and-clean-up-node-iteration-code-to-alloc-or-free.patch
mm-hugetlb-remove-redundant-list_empty-check-in-gather_surplus_pages.patch
mm-hugetlb-do-not-use-a-page-in-page-cache-for-cow-optimization.patch
mm-hugetlb-add-vm_noreserve-check-in-vma_has_reserves.patch
mm-hugetlb-remove-decrement_hugepage_resv_vma.patch
mm-hugetlb-decrement-reserve-count-if-vm_noreserve-alloc-page-cache.patch
mm-vmalloc-remove-useless-variable-in-vmap_block.patch
mm-vmalloc-use-well-defined-find_last_bit-func.patch
mm-hotplug-verify-hotplug-memory-range.patch
mm-hotplug-verify-hotplug-memory-range-fix.patch
mm-hotplug-remove-stop_machine-from-try_offline_node.patch
mm-hugetlb-protect-reserved-pages-when-soft-offlining-a-hugepage.patch
mm-hugetlb-change-variable-name-reservations-to-resv.patch
mm-hugetlb-fix-subpool-accounting-handling.patch
mm-hugetlb-remove-useless-check-about-mapping-type.patch
mm-hugetlb-grab-a-page_table_lock-after-page_cache_release.patch
mm-hugetlb-return-a-reserved-page-to-a-reserved-pool-if-failed.patch
mm-migrate-make-core-migration-code-aware-of-hugepage.patch
mm-soft-offline-use-migrate_pages-instead-of-migrate_huge_page.patch
migrate-add-hugepage-migration-code-to-migrate_pages.patch
mm-migrate-add-hugepage-migration-code-to-move_pages.patch
mm-mbind-add-hugepage-migration-code-to-mbind.patch
mm-migrate-remove-vm_hugetlb-from-vma-flag-check-in-vma_migratable.patch
mm-memory-hotplug-enable-memory-hotplug-to-handle-hugepage.patch
mm-migrate-check-movability-of-hugepage-in-unmap_and_move_huge_page.patch
mm-prepare-to-remove-proc-sys-vm-hugepages_treat_as_movable.patch
mm-prepare-to-remove-proc-sys-vm-hugepages_treat_as_movable-v2.patch
mm-mempolicy-rename-check_range-to-queue_pages_range.patch
mm-sparse-introduce-alloc_usemap_and_memmap.patch
mm-writeback-make-writeback_inodes_wb-static.patch
mm-vmalloc-use-wrapper-function-get_vm_area_size-to-caculate-size-of-vm-area.patch
hwpoison-always-unset-migrate_isolate-before-returning-from-soft_offline_page.patch
mm-hwpoison-fix-loss-of-pg_dirty-for-errors-on-mlocked-pages.patch
mm-hwpoison-dont-need-to-hold-compound-lock-for-hugetlbfs-page.patch
mm-hwpoison-fix-race-against-poison-thp.patch
mm-hwpoison-replace-atomic_long_sub-with-atomic_long_dec.patch
mm-hwpoison-dont-set-migration-type-twice-to-avoid-holding-heavily-contend-zone-lock.patch
mm-hwpoison-drop-forward-reference-declarations-__soft_offline_page.patch
mm-hwpoison-add-to-madvise_hwpoison.patch
mm-hwpoison-fix-memory-failure-still-holding-reference-count-after-unpoisoning-empty-zero-page.patch
linux-next.patch
mm-drop-actor-argument-of-do_generic_file_read.patch
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