On 23.03.2018 12:06, kbuild test robot wrote:
> Hi Kirill,
>
> Thank you for the patch! Perhaps something to improve:
>
> [auto build test WARNING on mmotm/master]
> [also build test WARNING on v4.16-rc6 next-20180322]
> [if your patch is applied to the wrong git tree, please drop us a note to
> help improve the system]
>
> url:
> https://github.com/0day-ci/linux/commits/Kirill-Tkhai/Improve-shrink_slab-scalability-old-complexity-was-O-n-2-new-is-O-n/20180323-052754
> base: git://git.cmpxchg.org/linux-mmotm.git master
> reproduce:
> # apt-get install sparse
> make ARCH=x86_64 allmodconfig
> make C=1 CF=-D__CHECK_ENDIAN__
>
>
> sparse warnings: (new ones prefixed by >>)
>
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:79:1: sparse: incorrect type in argument 3
> (different base types) @@ expected unsigned long [unsigned] flags @@
> got resunsigned long [unsigned] flags @@
> include/trace/events/vmscan.h:79:1: expected unsigned long [unsigned]
> flags
> include/trace/events/vmscan.h:79:1: got restricted gfp_t [usertype]
> gfp_flags
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:106:1: sparse: incorrect type in argument 3
> (different base types) @@ expected unsigned long [unsigned] flags @@
> got resunsigned long [unsigned] flags @@
> include/trace/events/vmscan.h:106:1: expected unsigned long [unsigned]
> flags
> include/trace/events/vmscan.h:106:1: got restricted gfp_t [usertype]
> gfp_flags
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: cast from restricted gfp_t
> include/trace/events/vmscan.h:196:1: sparse: too many warnings
>>> mm/vmscan.c:231:15: sparse: incompatible types in conditional expression
>>> (different address spaces)
>>> mm/vmscan.c:231:15: sparse: cast from unknown type
>>> mm/vmscan.c:231:15: sparse: incompatible types in conditional expression
>>> (different address spaces)
>>> mm/vmscan.c:231:15: sparse: incompatible types in conditional expression
>>> (different address spaces)
>>> mm/vmscan.c:231:15: sparse: cast from unknown type
>
> vim +231 mm/vmscan.c
Yeah, thanks for report.
>
> 205
> 206 static int memcg_expand_maps(struct mem_cgroup *memcg, int
> size, int old_size)
> 207 {
> 208 struct shrinkers_map *new, *old;
> 209 int i;
> 210
> 211 new = kvmalloc(sizeof(*new) + nr_node_ids *
> sizeof(new->map[0]),
> 212 GFP_KERNEL);
> 213 if (!new)
> 214 return -ENOMEM;
> 215
> 216 for (i = 0; i < nr_node_ids; i++) {
> 217 new->map[i] = kvmalloc_node(size, GFP_KERNEL,
> i);
> 218 if (!new->map[i]) {
> 219 while (--i >= 0)
> 220 kvfree(new->map[i]);
> 221 kvfree(new);
> 222 return -ENOMEM;
> 223 }
> 224
> 225 /* Set all old bits, clear all new bits */
> 226 memset(new->map[i], (int)0xff, old_size);
> 227 memset((void *)new->map[i] + old_size, 0, size
> - old_size);
> 228 }
> 229
> 230 lockdep_assert_held(&bitmap_rwsem);
> > 231 old = rcu_dereference_protected(SHRINKERS_MAP(memcg),
> true);
> 232
> 233 /*
> 234 * We don't want to use rcu_read_lock() in
> shrink_slab().
> 235 * Since expansion happens rare, we may just take the
> lock
> 236 * here.
> 237 */
> 238 if (old)
> 239 down_write(&shrinker_rwsem);
> 240
> 241 if (memcg)
> 242 rcu_assign_pointer(memcg->shrinkers_map, new);
> 243 else
> 244 rcu_assign_pointer(root_shrinkers_map, new);
> 245
> 246 if (old) {
> 247 up_write(&shrinker_rwsem);
> 248 call_rcu(&old->rcu, kvfree_map_rcu);
> 249 }
> 250
> 251 return 0;
> 252 }
> 253
>
> ---
> 0-DAY kernel test infrastructure Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all Intel Corporation
>
