tree: git://git.cmpxchg.org/linux-mmotm.git master
head: 8c7e96fa64e41f4571040f7fe9c279d0438ad172
commit: b45866989c31d4c38cbe7d788919e3e71721706f [87/135] mm/list_lru.c: prefetch neighboring list entries before acquiring lock
config: blackfin-allmodconfig (attached as .config)
compiler: bfin-uclinux-gcc (GCC) 6.2.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
git checkout b45866989c31d4c38cbe7d788919e3e71721706f
# save the attached .config to linux build tree
make.cross ARCH=blackfin
All errors (new ones prefixed by >>):
mm/list_lru.c: In function 'list_lru_del':
>> mm/list_lru.c:140:2: error: implicit declaration of function 'prefetchw' [-Werror=implicit-function-declaration]
prefetchw(item->prev);
^~~~~~~~~
cc1: some warnings being treated as errors
vim +/prefetchw +140 mm/list_lru.c
128
129 bool list_lru_del(struct list_lru *lru, struct list_head *item)
130 {
131 int nid = page_to_nid(virt_to_page(item));
132 struct list_lru_node *nlru = &lru->node[nid];
133 struct list_lru_one *l;
134
135 /*
136 * Prefetch the neighboring list entries to reduce lock hold time.
137 */
138 if (unlikely(list_empty(item)))
139 return false;
> 140 prefetchw(item->prev);
141 prefetchw(item->next);
142
143 spin_lock(&nlru->lock);
144 if (likely(!list_empty(item))) {
145 l = list_lru_from_kmem(nlru, item);
146 list_del_init(item);
147 l->nr_items--;
148 nlru->nr_items--;
149 spin_unlock(&nlru->lock);
150 return true;
151 }
152 spin_unlock(&nlru->lock);
153 return false;
154 }
155 EXPORT_SYMBOL_GPL(list_lru_del);
156
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
Attachment:
.config.gz
Description: application/gzip
