[rfc ] slub: unfreeze full page if it's in node partial

["Alex,Shi" <alex.shi@intel.com>]

In the per cpu partial slub, we may add a full page into node partial
list. like the following scenario:

        cpu1                                    cpu2 
    in unfreeze_partials                   in __slab_alloc
        ...
   add_partial(n, page, 1);
                                        alloced from cpu partial, and 
                                        set frozen = 1.
   second cmpxchg_double_slab()
   set frozen = 0


At that time, maybe we'd better to unfreeze it in acquire_slab(). That
let it in 'full list' mode, frozen=0 and freelist = NULL, same as we did
in __slab_alloc()


Signed-off-by: Alex Shi <alex.shi@intel.com>
---
 mm/slub.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 6fca71c..7846951 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1579,7 +1579,7 @@ static inline void *acquire_slab(struct kmem_cache *s,
 			new.inuse = page->objects;
 
 		VM_BUG_ON(new.frozen);
-		new.frozen = 1;
+		new.frozen = freelist != NULL;
 
 	} while (!__cmpxchg_double_slab(s, page,
 			freelist, counters,
-- 
1.7.0



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