2013-09-18 00:39:09

by Wanpeng Li

[permalink] [raw]
Subject: [PATCH v3 1/4] mm/hwpoison: fix traverse hugetlbfs page to avoid printk flood

madvise_hwpoison won't check if the page is small page or huge page and traverse
in small page granularity against the range unconditional, which result in a printk
flood "MCE xxx: already hardware poisoned" if the page is huge page. This patch fix
it by increase compound_order(compound_head(page)) for huge page iterator.

Testcase:

#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <errno.h>

#define PAGES_TO_TEST 3
#define PAGE_SIZE 4096 * 512

int main(void)
{
char *mem;
int i;

mem = mmap(NULL, PAGES_TO_TEST * PAGE_SIZE,
PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, 0, 0);

if (madvise(mem, PAGES_TO_TEST * PAGE_SIZE, MADV_HWPOISON) == -1)
return -1;

munmap(mem, PAGES_TO_TEST * PAGE_SIZE);

return 0;
}

Reviewed-by: Naoya Horiguchi <[email protected]>
Acked-by: Andi Kleen <[email protected]>
Signed-off-by: Wanpeng Li <[email protected]>
---
mm/madvise.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/madvise.c b/mm/madvise.c
index 6975bc8..539eeb9 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -343,10 +343,11 @@ static long madvise_remove(struct vm_area_struct *vma,
*/
static int madvise_hwpoison(int bhv, unsigned long start, unsigned long end)
{
+ struct page *p;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- for (; start < end; start += PAGE_SIZE) {
- struct page *p;
+ for (; start < end; start += PAGE_SIZE <<
+ compound_order(compound_head(p))) {
int ret;

ret = get_user_pages_fast(start, 1, 0, &p);
--
1.7.5.4


2013-09-18 00:39:12

by Wanpeng Li

[permalink] [raw]
Subject: [PATCH v3 2/4] mm/hwpoison: fix miss catch transparent huge page

Changelog:
*v1 -> v2: reverse PageTransHuge(page) && !PageHuge(page) check

PageTransHuge() can't guarantee the page is transparent huge page since it
return true for both transparent huge and hugetlbfs pages. This patch fix
it by check the page is also !hugetlbfs page.

Before patch:

[ 121.571128] Injecting memory failure at pfn 23a200
[ 121.571141] MCE 0x23a200: huge page recovery: Delayed
[ 140.355100] MCE: Memory failure is now running on 0x23a200

After patch:

[ 94.290793] Injecting memory failure at pfn 23a000
[ 94.290800] MCE 0x23a000: huge page recovery: Delayed
[ 105.722303] MCE: Software-unpoisoned page 0x23a000

Reviewed-by: Naoya Horiguchi <[email protected]>
Acked-by: Andi Kleen <[email protected]>
Signed-off-by: Wanpeng Li <[email protected]>
---
mm/memory-failure.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index e28ee77..ed41c63 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1349,7 +1349,7 @@ int unpoison_memory(unsigned long pfn)
* worked by memory_failure() and the page lock is not held yet.
* In such case, we yield to memory_failure() and make unpoison fail.
*/
- if (PageTransHuge(page)) {
+ if (!PageHuge(page) && PageTransHuge(page)) {
pr_info("MCE: Memory failure is now running on %#lx\n", pfn);
return 0;
}
--
1.7.5.4

2013-09-18 00:39:16

by Wanpeng Li

[permalink] [raw]
Subject: [PATCH v3 4/4] mm/hwpoison: fix the lack of one reference count against poisoned page

The lack of one reference count against poisoned page for hwpoison_inject w/o
hwpoison_filter enabled result in hwpoison detect -1 users still referenced
the page, however, the number should be 0 except the poison handler held one
after successfully unmap. This patch fix it by hold one referenced count against
poisoned page for hwpoison_inject w/ and w/o hwpoison_filter enabled.

Before patch:

[ 71.902112] Injecting memory failure at pfn 224706
[ 71.902137] MCE 0x224706: dirty LRU page recovery: Failed
[ 71.902138] MCE 0x224706: dirty LRU page still referenced by -1 users

After patch:

[ 94.710860] Injecting memory failure at pfn 215b68
[ 94.710885] MCE 0x215b68: dirty LRU page recovery: Recovered

Reviewed-by: Naoya Horiguchi <[email protected]>
Acked-by: Andi Kleen <[email protected]>
Signed-off-by: Wanpeng Li <[email protected]>
---
mm/hwpoison-inject.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/hwpoison-inject.c b/mm/hwpoison-inject.c
index afc2daa..4c84678 100644
--- a/mm/hwpoison-inject.c
+++ b/mm/hwpoison-inject.c
@@ -20,8 +20,6 @@ static int hwpoison_inject(void *data, u64 val)
if (!capable(CAP_SYS_ADMIN))
return -EPERM;

- if (!hwpoison_filter_enable)
- goto inject;
if (!pfn_valid(pfn))
return -ENXIO;

@@ -33,6 +31,9 @@ static int hwpoison_inject(void *data, u64 val)
if (!get_page_unless_zero(hpage))
return 0;

+ if (!hwpoison_filter_enable)
+ goto inject;
+
if (!PageLRU(p) && !PageHuge(p))
shake_page(p, 0);
/*
--
1.7.5.4

2013-09-18 00:39:38

by Wanpeng Li

[permalink] [raw]
Subject: [PATCH v3 3/4] mm/hwpoison: fix false report 2nd try page recovery

If the page is poisoned by software inject w/ MF_COUNT_INCREASED flag, there
is a false report 2nd try page recovery which is not truth, this patch fix it
by report first try free buddy page recovery if MF_COUNT_INCREASED is set.

Before patch:

[ 346.332041] Injecting memory failure at pfn 200010
[ 346.332189] MCE 0x200010: free buddy, 2nd try page recovery: Delayed

After patch:

[ 297.742600] Injecting memory failure at pfn 200010
[ 297.742941] MCE 0x200010: free buddy page recovery: Delayed

Reviewed-by: Naoya Horiguchi <[email protected]>
Acked-by: Andi Kleen <[email protected]>
Signed-off-by: Wanpeng Li <[email protected]>
---
mm/memory-failure.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ed41c63..615764c 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1114,8 +1114,10 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
* shake_page could have turned it free.
*/
if (is_free_buddy_page(p)) {
- action_result(pfn, "free buddy, 2nd try",
- DELAYED);
+ if (flags & MF_COUNT_INCREASED)
+ action_result(pfn, "free buddy", DELAYED);
+ else
+ action_result(pfn, "free buddy, 2nd try", DELAYED);
return 0;
}
action_result(pfn, "non LRU", IGNORED);
--
1.7.5.4