On Fri, Jul 24, 2015 at 07:14:46PM +0800, kbuild test robot wrote:
> tree: git://git.cmpxchg.org/linux-mmotm.git master
> head: 61f5f835b6f06fbc233481b5d3c0afd71ecf54e8
> commit: a06e045a2c99e39bf342ccb5dbbd6655f3814238 [260/385] proc: add kpageidle file
> reproduce:
> # apt-get install sparse
> git checkout a06e045a2c99e39bf342ccb5dbbd6655f3814238
> make ARCH=x86_64 allmodconfig
> make C=1 CF=-D__CHECK_ENDIAN__
>
>
> sparse warnings: (new ones prefixed by >>)
>
> >> include/linux/mmu_notifier.h:247:19: sparse: context imbalance in 'kpageidle_clear_pte_refs_one' - unexpected unlock
>
> vim +/kpageidle_clear_pte_refs_one +247 include/linux/mmu_notifier.h
>
> cddb8a5c Andrea Arcangeli 2008-07-28 231
> cddb8a5c Andrea Arcangeli 2008-07-28 232 static inline void mmu_notifier_release(struct mm_struct *mm)
> cddb8a5c Andrea Arcangeli 2008-07-28 233 {
> cddb8a5c Andrea Arcangeli 2008-07-28 234 if (mm_has_notifiers(mm))
> cddb8a5c Andrea Arcangeli 2008-07-28 235 __mmu_notifier_release(mm);
> cddb8a5c Andrea Arcangeli 2008-07-28 236 }
> cddb8a5c Andrea Arcangeli 2008-07-28 237
> cddb8a5c Andrea Arcangeli 2008-07-28 238 static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
> 57128468 Andres Lagar-Cavilla 2014-09-22 239 unsigned long start,
> 57128468 Andres Lagar-Cavilla 2014-09-22 240 unsigned long end)
> cddb8a5c Andrea Arcangeli 2008-07-28 241 {
> cddb8a5c Andrea Arcangeli 2008-07-28 242 if (mm_has_notifiers(mm))
> 57128468 Andres Lagar-Cavilla 2014-09-22 243 return __mmu_notifier_clear_flush_young(mm, start, end);
> cddb8a5c Andrea Arcangeli 2008-07-28 244 return 0;
> cddb8a5c Andrea Arcangeli 2008-07-28 245 }
> cddb8a5c Andrea Arcangeli 2008-07-28 246
> 59eaee21 Vladimir Davydov 2015-07-23 @247 static inline int mmu_notifier_clear_young(struct mm_struct *mm,
> 59eaee21 Vladimir Davydov 2015-07-23 248 unsigned long start,
> 59eaee21 Vladimir Davydov 2015-07-23 249 unsigned long end)
> 59eaee21 Vladimir Davydov 2015-07-23 250 {
> 59eaee21 Vladimir Davydov 2015-07-23 251 if (mm_has_notifiers(mm))
> 59eaee21 Vladimir Davydov 2015-07-23 252 return __mmu_notifier_clear_young(mm, start, end);
> 59eaee21 Vladimir Davydov 2015-07-23 253 return 0;
> 59eaee21 Vladimir Davydov 2015-07-23 254 }
> 59eaee21 Vladimir Davydov 2015-07-23 255
Looks like this warning is issued, because page_check_address, used by
kpageidle_clear_pte_refs_one, is not annotated as acquiring a ptl lock.
It is false-positive then.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>