From: Andi Kleen <a...@linux.intel.com>
Can as well do the normal conditional resched check out of line.
This saves one function call.
Signed-off-by: Andi Kleen <a...@linux.intel.com>
---
arch/x86/include/asm/uaccess_64.h | 6 ++++--
arch/x86/lib/copy_user_nocache_64.S | 7 +++++++
2 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/uaccess_64.h
b/arch/x86/include/asm/uaccess_64.h
index b327057..831f4a3 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -243,12 +243,14 @@ __copy_to_user_inatomic(void __user *dst, const void
*src, unsigned size)
extern long __copy_user_nocache(void *dst, const void __user *src,
unsigned size, int zerorest);
+extern long __copy_user_nocache_might_fault(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)
{
- might_fault();
- return __copy_user_nocache(dst, src, size, 1);
+ might_fault_debug_only();
+ return __copy_user_nocache_might_fault(dst, src, size, 1);
}
static inline int
diff --git a/arch/x86/lib/copy_user_nocache_64.S
b/arch/x86/lib/copy_user_nocache_64.S
index 6a4f43c..8e6b0bd 100644
--- a/arch/x86/lib/copy_user_nocache_64.S
+++ b/arch/x86/lib/copy_user_nocache_64.S
@@ -16,6 +16,7 @@
#include <asm/thread_info.h>
#include <asm/asm.h>
#include <asm/smap.h>
+#include "user-common.h"
.macro ALIGN_DESTINATION
#ifdef FIX_ALIGNMENT
@@ -43,6 +44,12 @@
#endif
.endm
+ENTRY(__copy_user_nocache_might_fault)
+ CFI_STARTPROC
+ GET_THREAD_AND_SCHEDULE %rax
+ CFI_ENDPROC
+ /* fall through */
+
/*
* copy_user_nocache - Uncached memory copy with exception handling
* This will force destination/source out of cache for more performance.
--
1.8.3.1
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