On Mon, May 20, 2019 at 05:37:41AM +0530, Amit Kumar wrote:
HI,
mm/slub.c: line 3973 int __kmem_cache_shrink(struct kmem_cache *s) { int node; int i; struct kmem_cache_node *n; struct page *page; struct page *t; struct list_head discard; struct list_head promote[SHRINK_PROMOTE_MAX]; unsigned long flags; int ret = 0;
flush_all(s); for_each_kmem_cache_node(s, node, n) {
How uninitialized variable node is being used in macro for_each_kmem_cache_node?
node is a local variable with no extern and not initialized.
mm/slab.h: line 490 #define for_each_kmem_cache_node(__s, __node, __n) \ for (__node = 0; __node < nr_node_ids; __node++) \ if ((__n = get_node(__s, __node)))
As we see for loop is based on node.
Hi, This sentence is almost correct. The for loop is *not based* on node but *uses* the node variable. If you check, __node gets initialised to 0 at the beginning of the for loop. So whatever you use that macro with will be initialised to 0 at the beginning of the for loop. Bests, Máté
Thanks in advance.
Regards, Amit Kumar