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 <[email protected]> Reviewed-by: Chen, Gong <[email protected]> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
