HWPOISON: Remove retry loop for try_to_unmap

We don't reply in other temporary failure cases and there were no
reports of replies happening. I think the original reason it was
added was also just an early bug, not an observation of the race.

So remove the loop for now, but keep a warning message.

Signed-off-by: Andi Kleen <ak@linux.intel.com>

1 files changed, 1 insertions, 14 deletions

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 88653c93e4c..2044fe8920c 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -840,8 +840,6 @@ static int page_action(struct page_state *ps, struct page *p,
         return (result == RECOVERED || result == DELAYED) ? 0 : -EBUSY;
 }
 
-#define N_UNMAP_TRIES 5
-
 /*
  * Do all that is necessary to remove user space mappings. Unmap
  * the pages and send SIGBUS to the processes if the data was dirty.
@@ -853,7 +851,6 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
         struct address_space *mapping;
         LIST_HEAD(tokill);
         int ret;
-        int i;
         int kill = 1;
         struct page *hpage = compound_head(p);
 
@@ -907,17 +904,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
         if (kill)
                 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(hpage, ttu);
-                if (ret == SWAP_SUCCESS)
-                        break;
-                pr_debug("MCE %#lx: try_to_unmap retry needed %d\n", pfn,  ret);
-        }
-
+        ret = try_to_unmap(hpage, ttu);
         if (ret != SWAP_SUCCESS)
                 printk(KERN_ERR "MCE %#lx: failed to unmap page (mapcount=%d)\n",
                                 pfn, page_mapcount(hpage));