slab: remove one NR_CPUS dependency

Reduce high order allocations in do_tune_cpucache() for some setups.
(NR_CPUS=4096 -> we need 64KB)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/mm/slab.c b/mm/slab.c
index 1e523ed..b80282a 100644 (file)
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3934,7 +3934,7 @@ fail:
 
 struct ccupdate_struct {
        struct kmem_cache *cachep;
-       struct array_cache *new[NR_CPUS];
+       struct array_cache *new[0];
 };
 
 static void do_ccupdate_local(void *info)
@@ -3956,7 +3956,8 @@ static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
        struct ccupdate_struct *new;
        int i;
 
-       new = kzalloc(sizeof(*new), gfp);
+       new = kzalloc(sizeof(*new) + nr_cpu_ids * sizeof(struct array_cache *),
+                     gfp);
        if (!new)
                return -ENOMEM;