Commit 7013febc authored by Naoya Horiguchi's avatar Naoya Horiguchi Committed by Andi Kleen
Browse files

HWPOISON, hugetlb: set/clear PG_hwpoison bits on hugepage



To avoid race condition between concurrent memory errors on identified
hugepage, we atomically test and set PG_hwpoison bit on the head page.
All pages in the error hugepage are considered as hwpoisoned
for now, so set and clear all PG_hwpoison bits in the hugepage
with page lock of the head page held.

Dependency:
  "HWPOISON, hugetlb: enable error handling path for hugepage"
Signed-off-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: default avatarFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
parent 7af446a8
......@@ -920,6 +920,22 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
return ret;
}
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);
}
int __memory_failure(unsigned long pfn, int trapno, int flags)
{
struct page_state *ps;
......@@ -1014,6 +1030,26 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
return 0;
}
/*
* For error on the tail page, we should set PG_hwpoison
* on the head page to show that the hugepage is hwpoisoned
*/
if (PageTail(p) && TestSetPageHWPoison(hpage)) {
action_result(pfn, "hugepage already hardware poisoned",
IGNORED);
unlock_page(hpage);
put_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);
wait_on_page_writeback(p);
/*
......@@ -1118,6 +1154,8 @@ int unpoison_memory(unsigned long pfn)
atomic_long_dec(&mce_bad_pages);
freeit = 1;
}
if (PageHuge(p))
clear_page_hwpoison_huge_page(page);
unlock_page(page);
put_page(page);
......
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