Messages in this thread Patch in this message | | | From | Andi Kleen <> | Subject | [PATCH 13/13] x86: drop cond rescheds from __copy_{from,to}_user | Date | Fri, 9 Aug 2013 16:04:20 -0700 |
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From: Andi Kleen <ak@linux.intel.com>
The __copy_* variants are right now more expensive than the non __ copy*user in CONFIG_PREEMPT_VOLUNTARY because they have a additional function call to might_fault().
Since they are usually used in a row with other functions, which also schedule or only in the thin compat layers and also __get/__put_user do not do explicit reschedule check drop them here for the non debug case.
Normal non __ copy*user will still schedule of course
Signed-off-by: Andi Kleen <ak@linux.intel.com> --- arch/x86/include/asm/uaccess_32.h | 6 +++--- arch/x86/include/asm/uaccess_64.h | 4 ++-- 2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h index 7f760a9..e656ee9 100644 --- a/arch/x86/include/asm/uaccess_32.h +++ b/arch/x86/include/asm/uaccess_32.h @@ -81,7 +81,7 @@ __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) static __always_inline unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n) { - might_fault(); + might_fault_debug_only(); return __copy_to_user_inatomic(to, from, n); } @@ -136,7 +136,7 @@ __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) static __always_inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n) { - might_fault(); + might_fault_debug_only(); if (__builtin_constant_p(n)) { unsigned long ret; @@ -158,7 +158,7 @@ __copy_from_user(void *to, const void __user *from, unsigned long n) static __always_inline unsigned long __copy_from_user_nocache(void *to, const void __user *from, unsigned long n) { - might_fault(); + might_fault_debug_only(); if (__builtin_constant_p(n)) { unsigned long ret; diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index 831f4a3..86959f5 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -122,7 +122,7 @@ int __copy_from_user_nocheck(void *dst, const void __user *src, unsigned size) static __always_inline __must_check int __copy_from_user(void *dst, const void __user *src, unsigned size) { - might_fault(); + might_fault_debug_only(); return __copy_from_user_nocheck(dst, src, size); } @@ -172,7 +172,7 @@ int __copy_to_user_nocheck(void __user *dst, const void *src, unsigned size) static __always_inline __must_check int __copy_to_user(void __user *dst, const void *src, unsigned size) { - might_fault(); + might_fault_debug_only(); return __copy_to_user_nocheck(dst, src, size); } -- 1.8.3.1
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