[PATCH 2/7] HWPOISON, hugetlb: enable error handling path for hugepage

From: Naoya Horiguchi
Date: Thu May 13 2010 - 03:58:48 EST


This patch just enables handling path. Real containing and
recovering operation will be implemented in following patches.

Dependency:
"hugetlb, rmap: add reverse mapping for hugepage."

Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Wu Fengguang <fengguang.wu@xxxxxxxxx>
---
mm/memory-failure.c | 39 ++++++++++++++++++++++-----------------
1 files changed, 22 insertions(+), 17 deletions(-)

diff --git v2.6.34-rc7/mm/memory-failure.c v2.6.34-rc7/mm/memory-failure.c
index 620b0b4..1ec68c8 100644
--- v2.6.34-rc7/mm/memory-failure.c
+++ v2.6.34-rc7/mm/memory-failure.c
@@ -45,6 +45,7 @@
#include <linux/page-isolation.h>
#include <linux/suspend.h>
#include <linux/slab.h>
+#include <linux/hugetlb.h>
#include "internal.h"

int sysctl_memory_failure_early_kill __read_mostly = 0;
@@ -837,6 +838,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
int ret;
int i;
int kill = 1;
+ struct page *hpage = compound_head(p);

if (PageReserved(p) || PageSlab(p))
return SWAP_SUCCESS;
@@ -845,10 +847,10 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
* This check implies we don't kill processes if their pages
* are in the swap cache early. Those are always late kills.
*/
- if (!page_mapped(p))
+ if (!page_mapped(hpage))
return SWAP_SUCCESS;

- if (PageCompound(p) || PageKsm(p))
+ if (PageKsm(p))
return SWAP_FAIL;

if (PageSwapCache(p)) {
@@ -863,10 +865,11 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
* XXX: the dirty test could be racy: set_page_dirty() may not always
* be called inside page lock (it's recommended but not enforced).
*/
- mapping = page_mapping(p);
- if (!PageDirty(p) && mapping && mapping_cap_writeback_dirty(mapping)) {
- if (page_mkclean(p)) {
- SetPageDirty(p);
+ mapping = page_mapping(hpage);
+ if (!PageDirty(hpage) && mapping &&
+ mapping_cap_writeback_dirty(mapping)) {
+ if (page_mkclean(hpage)) {
+ SetPageDirty(hpage);
} else {
kill = 0;
ttu |= TTU_IGNORE_HWPOISON;
@@ -885,14 +888,14 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
* there's nothing that can be done.
*/
if (kill)
- collect_procs(p, &tokill);
+ collect_procs(hpage, &tokill);

/*
* try_to_unmap can fail temporarily due to races.
* Try a few times (RED-PEN better strategy?)
*/
for (i = 0; i < N_UNMAP_TRIES; i++) {
- ret = try_to_unmap(p, ttu);
+ ret = try_to_unmap(hpage, ttu);
if (ret == SWAP_SUCCESS)
break;
pr_debug("MCE %#lx: try_to_unmap retry needed %d\n", pfn, ret);
@@ -900,7 +903,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,

if (ret != SWAP_SUCCESS)
printk(KERN_ERR "MCE %#lx: failed to unmap page (mapcount=%d)\n",
- pfn, page_mapcount(p));
+ pfn, page_mapcount(hpage));

/*
* Now that the dirty bit has been propagated to the
@@ -911,7 +914,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
* use a more force-full uncatchable kill to prevent
* any accesses to the poisoned memory.
*/
- kill_procs_ao(&tokill, !!PageDirty(p), trapno,
+ kill_procs_ao(&tokill, !!PageDirty(hpage), trapno,
ret != SWAP_SUCCESS, pfn);

return ret;
@@ -921,6 +924,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
{
struct page_state *ps;
struct page *p;
+ struct page *hpage;
int res;

if (!sysctl_memory_failure_recovery)
@@ -934,6 +938,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
}

p = pfn_to_page(pfn);
+ hpage = compound_head(p);
if (TestSetPageHWPoison(p)) {
printk(KERN_ERR "MCE %#lx: already hardware poisoned\n", pfn);
return 0;
@@ -953,7 +958,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
* that may make page_freeze_refs()/page_unfreeze_refs() mismatch.
*/
if (!(flags & MF_COUNT_INCREASED) &&
- !get_page_unless_zero(compound_head(p))) {
+ !get_page_unless_zero(hpage)) {
if (is_free_buddy_page(p)) {
action_result(pfn, "free buddy", DELAYED);
return 0;
@@ -971,9 +976,9 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
* The check (unnecessarily) ignores LRU pages being isolated and
* walked by the page reclaim code, however that's not a big loss.
*/
- if (!PageLRU(p))
+ if (!PageLRU(p) && !PageHuge(p))
shake_page(p, 0);
- if (!PageLRU(p)) {
+ if (!PageLRU(p) && !PageHuge(p)) {
/*
* shake_page could have turned it free.
*/
@@ -991,7 +996,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
* It's very difficult to mess with pages currently under IO
* and in many cases impossible, so we just avoid it here.
*/
- lock_page_nosync(p);
+ lock_page_nosync(hpage);

/*
* unpoison always clear PG_hwpoison inside page lock
@@ -1004,8 +1009,8 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
if (hwpoison_filter(p)) {
if (TestClearPageHWPoison(p))
atomic_long_dec(&mce_bad_pages);
- unlock_page(p);
- put_page(p);
+ unlock_page(hpage);
+ put_page(hpage);
return 0;
}

@@ -1038,7 +1043,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
}
}
out:
- unlock_page(p);
+ unlock_page(hpage);
return res;
}
EXPORT_SYMBOL_GPL(__memory_failure);
--
1.7.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/