mm: hwpoison: change PageHWPoison behavior on hugetlb pages
We'd like to narrow down the error region in memory error on hugetlb
pages. However, currently we set PageHWPoison flags on all subpages in
the error hugepage and add # of subpages to num_hwpoison_pages, which
doesn't fit our purpose.
So this patch changes the behavior and we only set PageHWPoison on the
head page then increase num_hwpoison_pages only by 1. This is a
preparation for narrow-down part which comes in later patches.
Link: http://lkml.kernel.org/r/1496305019-5493-4-git-send-email-n-horiguchi@ah.jp.nec.com
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index e3bf643..a9ddb0e 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1009,22 +1009,6 @@
return unmap_success;
}
-static void set_page_hwpoison_huge_page(struct page *hpage)
-{
- int i;
- int nr_pages = 1 << compound_order(hpage);
- for (i = 0; i < nr_pages; i++)
- SetPageHWPoison(hpage + i);
-}
-
-static void clear_page_hwpoison_huge_page(struct page *hpage)
-{
- int i;
- int nr_pages = 1 << compound_order(hpage);
- for (i = 0; i < nr_pages; i++)
- ClearPageHWPoison(hpage + i);
-}
-
/**
* memory_failure - Handle memory failure of a page.
* @pfn: Page Number of the corrupted page
@@ -1050,7 +1034,6 @@
struct page *hpage;
struct page *orig_head;
int res;
- unsigned int nr_pages;
unsigned long page_flags;
if (!sysctl_memory_failure_recovery)
@@ -1064,24 +1047,23 @@
p = pfn_to_page(pfn);
orig_head = hpage = compound_head(p);
+
+ /* tmporary check code, to be updated in later patches */
+ if (PageHuge(p)) {
+ if (TestSetPageHWPoison(hpage)) {
+ pr_err("Memory failure: %#lx: already hardware poisoned\n", pfn);
+ return 0;
+ }
+ goto tmp;
+ }
if (TestSetPageHWPoison(p)) {
pr_err("Memory failure: %#lx: already hardware poisoned\n",
pfn);
return 0;
}
- /*
- * Currently errors on hugetlbfs pages are measured in hugepage units,
- * so nr_pages should be 1 << compound_order. OTOH when errors are on
- * transparent hugepages, they are supposed to be split and error
- * measurement is done in normal page units. So nr_pages should be one
- * in this case.
- */
- if (PageHuge(p))
- nr_pages = 1 << compound_order(hpage);
- else /* normal page or thp */
- nr_pages = 1;
- num_poisoned_pages_add(nr_pages);
+tmp:
+ num_poisoned_pages_inc();
/*
* We need/can do nothing about count=0 pages.
@@ -1109,12 +1091,11 @@
if (PageHWPoison(hpage)) {
if ((hwpoison_filter(p) && TestClearPageHWPoison(p))
|| (p != hpage && TestSetPageHWPoison(hpage))) {
- num_poisoned_pages_sub(nr_pages);
+ num_poisoned_pages_dec();
unlock_page(hpage);
return 0;
}
}
- set_page_hwpoison_huge_page(hpage);
res = dequeue_hwpoisoned_huge_page(hpage);
action_result(pfn, MF_MSG_FREE_HUGE,
res ? MF_IGNORED : MF_DELAYED);
@@ -1137,7 +1118,7 @@
pr_err("Memory failure: %#lx: thp split failed\n",
pfn);
if (TestClearPageHWPoison(p))
- num_poisoned_pages_sub(nr_pages);
+ num_poisoned_pages_dec();
put_hwpoison_page(p);
return -EBUSY;
}
@@ -1193,14 +1174,14 @@
*/
if (!PageHWPoison(p)) {
pr_err("Memory failure: %#lx: just unpoisoned\n", pfn);
- num_poisoned_pages_sub(nr_pages);
+ num_poisoned_pages_dec();
unlock_page(hpage);
put_hwpoison_page(hpage);
return 0;
}
if (hwpoison_filter(p)) {
if (TestClearPageHWPoison(p))
- num_poisoned_pages_sub(nr_pages);
+ num_poisoned_pages_dec();
unlock_page(hpage);
put_hwpoison_page(hpage);
return 0;
@@ -1219,14 +1200,6 @@
put_hwpoison_page(hpage);
return 0;
}
- /*
- * Set PG_hwpoison on all pages in an error hugepage,
- * because containment is done in hugepage unit for now.
- * Since we have done TestSetPageHWPoison() for the head page with
- * page lock held, we can safely set PG_hwpoison bits on tail pages.
- */
- if (PageHuge(p))
- set_page_hwpoison_huge_page(hpage);
/*
* It's very difficult to mess with pages currently under IO
@@ -1397,7 +1370,6 @@
struct page *page;
struct page *p;
int freeit = 0;
- unsigned int nr_pages;
static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL,
DEFAULT_RATELIMIT_BURST);
@@ -1442,8 +1414,6 @@
return 0;
}
- nr_pages = 1 << compound_order(page);
-
if (!get_hwpoison_page(p)) {
/*
* Since HWPoisoned hugepage should have non-zero refcount,
@@ -1473,10 +1443,8 @@
if (TestClearPageHWPoison(page)) {
unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",
pfn, &unpoison_rs);
- num_poisoned_pages_sub(nr_pages);
+ num_poisoned_pages_dec();
freeit = 1;
- if (PageHuge(page))
- clear_page_hwpoison_huge_page(page);
}
unlock_page(page);
@@ -1608,14 +1576,10 @@
ret = -EIO;
} else {
/* overcommit hugetlb page will be freed to buddy */
- if (PageHuge(page)) {
- set_page_hwpoison_huge_page(hpage);
+ SetPageHWPoison(page);
+ if (PageHuge(page))
dequeue_hwpoisoned_huge_page(hpage);
- num_poisoned_pages_add(1 << compound_order(hpage));
- } else {
- SetPageHWPoison(page);
- num_poisoned_pages_inc();
- }
+ num_poisoned_pages_inc();
}
return ret;
}
@@ -1731,15 +1695,12 @@
static void soft_offline_free_page(struct page *page)
{
- if (PageHuge(page)) {
- struct page *hpage = compound_head(page);
+ struct page *head = compound_head(page);
- set_page_hwpoison_huge_page(hpage);
- if (!dequeue_hwpoisoned_huge_page(hpage))
- num_poisoned_pages_add(1 << compound_order(hpage));
- } else {
- if (!TestSetPageHWPoison(page))
- num_poisoned_pages_inc();
+ if (!TestSetPageHWPoison(head)) {
+ num_poisoned_pages_inc();
+ if (PageHuge(head))
+ dequeue_hwpoisoned_huge_page(head);
}
}