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From: Amit Kumar <>
	 Kernel Newbies <>
Subject: Unable to understand a piece of code
Date: Mon, 20 May 2019 05:37:41 +0530
Message-ID: <> (raw)


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;

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.

Thanks in advance.

Amit Kumar

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Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-20  0:07 Amit Kumar [this message]
2019-05-20  1:23 ` Tobin C. Harding
2019-05-20  3:33   ` Amit Kumar
2019-05-22 17:57 ` Máté Eckl

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