Introduce hpc.page_isolated to record if page is assured to be
isolated, ie. it won't be accessed in normal kernel code paths
and therefore won't trigger another MCE event.
__memory_failure() will now return 0 to indicate that page is
really isolated. Note that the original used action result
RECOVERED is not a reliable criterion.
Note that we now don't bother to risk returning 0 for the
rare unpoison/truncated cases.
CC: Andi Kleen <andi@xxxxxxxxxxxxxx>
Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
---
mm/memory-failure.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
--- linux-mm.orig/mm/memory-failure.c 2009-11-30 20:35:49.000000000 +0800
+++ linux-mm/mm/memory-failure.c 2009-11-30 20:40:56.000000000 +0800
@@ -332,6 +332,7 @@ struct hwpoison_control {
struct page *p; /* raw corrupted page */
struct page *page; /* compound page head */
int result;
+ unsigned page_isolated:1;
};
/*
@@ -529,9 +530,10 @@ static int me_swapcache_dirty(struct hwp
/* Trigger EIO in shmem: */
ClearPageUptodate(p);
- if (!delete_from_lru_cache(p))
+ if (!delete_from_lru_cache(p)) {
+ hpc->page_isolated = 1;
return DELAYED;
- else
+ } else
return FAILED;
}
@@ -641,7 +643,7 @@ static void action_result(struct hwpoiso
msg, hwpoison_result_name[result]);
}
-static int page_action(struct page_state *ps,
+static void page_action(struct page_state *ps,
struct hwpoison_control *hpc)
{
int result;
@@ -656,12 +658,15 @@ static int page_action(struct page_state
"MCE %#lx: %s page still referenced by %d users\n",
hpc->pfn, ps->msg, count);
+ if (result == RECOVERED)
+ hpc->page_isolated = 1;
+ if (count || page_mapcount(hpc->page))
+ hpc->page_isolated = 0;
+
/* Could do more checks here if page looks ok */
/*
* Could adjust zone counters here to correct for the missing page.
*/
-
- return result == RECOVERED ? 0 : -EBUSY;
}
#define N_UNMAP_TRIES 5
@@ -767,7 +772,6 @@ int __memory_failure(unsigned long pfn,
struct page_state *ps;
struct page *p;
struct page *page;
- int res;
if (!sysctl_memory_failure_recovery)
panic("Memory failure from trap %d on page %lx", trapno, pfn);
@@ -785,6 +789,7 @@ int __memory_failure(unsigned long pfn,
hpc.pfn = pfn;
hpc.p = p;
hpc.page = page;
+ hpc.page_isolated = 0;
if (TestSetPageHWPoison(p)) {
action_result(&hpc, "already hardware poisoned", IGNORED);
@@ -842,7 +847,6 @@ int __memory_failure(unsigned long pfn,
*/
if (!PageHWPoison(p)) {
action_result(&hpc, "unpoisoned", IGNORED);
- res = 0;
goto out;
}
@@ -852,30 +856,26 @@ int __memory_failure(unsigned long pfn,
* Now take care of user space mappings.
* Abort on fail: __remove_from_page_cache() assumes unmapped page.
*/
- if (hwpoison_user_mappings(&hpc, trapno) != SWAP_SUCCESS) {
- res = -EBUSY;
+ if (hwpoison_user_mappings(&hpc, trapno) != SWAP_SUCCESS)
goto out;
- }
/*
* Torn down by someone else?
*/
if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) {
action_result(&hpc, "already truncated LRU", IGNORED);
- res = 0;
goto out;
}
- res = -EBUSY;
for (ps = error_states;; ps++) {
if ((p->flags & ps->mask) == ps->res) {
- res = page_action(ps, &hpc);
+ page_action(ps, &hpc);
break;
}
}
out:
unlock_page(p);
- return res;
+ return hpc.page_isolated ? 0 : -EBUSY;
}
EXPORT_SYMBOL_GPL(__memory_failure);
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