Chen Gong pointed out that set/unset_migratetype_isolate() was done in
different functions in mm/memory-failure.c, which makes the code less
readable/maintenable. So this patch makes it done in soft_offline_page().
With this patch, we get to hold lock_memory_hotplug() longer but it's not
a problem because races between memory hotplug and soft offline are very rare.
This patch is against next-20130910.
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Reviewed-by: Chen, Gong <gong.chen@xxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 36 +++++++++++++++++-------------------
1 file changed, 17 insertions(+), 19 deletions(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 947ed54..702e1e1 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1421,19 +1421,6 @@ static int __get_any_page(struct page *p, unsigned long pfn, int flags)
return 1;
/*
- * The lock_memory_hotplug prevents a race with memory hotplug.
- * This is a big hammer, a better would be nicer.
- */
- lock_memory_hotplug();
-
- /*
- * Isolate the page, so that it doesn't get reallocated if it
- * was free. This flag should be kept set until the source page
- * is freed and PG_hwpoison on it is set.
- */
- if (get_pageblock_migratetype(p) != MIGRATE_ISOLATE)
- set_migratetype_isolate(p, true);
- /*
* When the target page is a free hugepage, just remove it
* from free hugepage list.
*/
@@ -1453,7 +1440,6 @@ static int __get_any_page(struct page *p, unsigned long pfn, int flags)
/* Not a free page */
ret = 1;
}
- unlock_memory_hotplug();
return ret;
}
@@ -1652,15 +1638,28 @@ int soft_offline_page(struct page *page, int flags)
}
}
+ /*
+ * The lock_memory_hotplug prevents a race with memory hotplug.
+ * This is a big hammer, a better would be nicer.
+ */
+ lock_memory_hotplug();
+
+ /*
+ * Isolate the page, so that it doesn't get reallocated if it
+ * was free. This flag should be kept set until the source page
+ * is freed and PG_hwpoison on it is set.
+ */
+ if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
+ set_migratetype_isolate(page, true);
+
ret = get_any_page(page, pfn, flags);
- if (ret < 0)
- goto unset;
- if (ret) { /* for in-use pages */
+ unlock_memory_hotplug();
+ if (ret > 0) { /* for in-use pages */
if (PageHuge(page))
ret = soft_offline_huge_page(page, flags);
else
ret = __soft_offline_page(page, flags);
- } else { /* for free pages */
+ } else if (ret == 0) { /* for free pages */
if (PageHuge(page)) {
set_page_hwpoison_huge_page(hpage);
dequeue_hwpoisoned_huge_page(hpage);
@@ -1671,7 +1670,6 @@ int soft_offline_page(struct page *page, int flags)
atomic_long_inc(&num_poisoned_pages);
}
}
-unset:
unset_migratetype_isolate(page, MIGRATE_MOVABLE);
return ret;
}
--
1.8.3.1
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