diff options
Diffstat (limited to 'arch/x86/include/asm/uaccess_64.h')
| -rw-r--r-- | arch/x86/include/asm/uaccess_64.h | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index 84210c479fca..dcaa0404cf7b 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -189,17 +189,28 @@ extern long __copy_user_nocache(void *dst, const void __user *src, unsigned size, int zerorest); static inline int __copy_from_user_nocache(void *dst, const void __user *src, - unsigned size) + unsigned size, unsigned long total) { might_sleep(); - return __copy_user_nocache(dst, src, size, 1); + /* + * In practice this limit means that large file write()s + * which get chunked to 4K copies get handled via + * non-temporal stores here. Smaller writes get handled + * via regular __copy_from_user(): + */ + if (likely(total >= PAGE_SIZE)) + return __copy_user_nocache(dst, src, size, 1); + else + return __copy_from_user(dst, src, size); } static inline int __copy_from_user_inatomic_nocache(void *dst, - const void __user *src, - unsigned size) + const void __user *src, unsigned size, unsigned total) { - return __copy_user_nocache(dst, src, size, 0); + if (likely(total >= PAGE_SIZE)) + return __copy_user_nocache(dst, src, size, 0); + else + return __copy_from_user_inatomic(dst, src, size); } unsigned long |