Re: [patch 3/3] NUMA slab locking fixes -- fix cpu down and up locking

[Andrew Morton <akpm@osdl.org>]

Andrew Morton <akpm@osdl.org> wrote:
>
> Cleanup patch below.

After which we need to address this:

mm/slab.c: In function `cpuup_callback':
mm/slab.c:959: warning: `alien' might be used uninitialized in this function

I guess it won't cause crashes, but it makes me wonder if this was tested
on non-NUMA?

Is this right?

--- devel/mm/slab.c~numa-slab-locking-fixes-fix-cpu-down-and-up-locking-fix	2006-02-04 02:01:44.000000000 -0800
+++ devel-akpm/mm/slab.c	2006-02-04 02:01:44.000000000 -0800
@@ -901,8 +901,11 @@ static void drain_alien_cache(struct kme
 }
 #else
 #define alloc_alien_cache(node, limit) do { } while (0)
-#define free_alien_cache(ac_ptr) do { } while (0)
 #define drain_alien_cache(cachep, alien) do { } while (0)
+
+static inline void free_alien_cache(struct array_cache **ac_ptr)
+{
+}
 #endif
 
 static int __devinit cpuup_callback(struct notifier_block *nfb,
@@ -986,10 +989,12 @@ static int __devinit cpuup_callback(stru
 				l3->shared = shared;
 				shared = NULL;
 			}
+#ifdef CONFIG_NUMA
 			if (!l3->alien) {
 				l3->alien = alien;
 				alien = NULL;
 			}
+#endif
 			spin_unlock_irq(&l3->list_lock);
 
 			kfree(shared);
_