提交 87e1652c 编写于 作者: A Andi Kleen 提交者: Andi Kleen

[PATCH] x86-64: Don't keep interrupts disabled while spinning in spinlocks

Follows i386.

Based on patch from some folks at Google (MikeW, Edward G.?), but
completely redone by AK.
Signed-off-by: NAndi Kleen <ak@suse.de>
上级 a63954b5
......@@ -36,7 +36,34 @@ static inline void __raw_spin_lock(raw_spinlock_t *lock)
"2:\t" : "=m" (lock->slock) : : "memory");
}
#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
/*
* Same as __raw_spin_lock, but reenable interrupts during spinning.
*/
#ifndef CONFIG_PROVE_LOCKING
static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
{
asm volatile(
"\n1:\t"
LOCK_PREFIX " ; decl %0\n\t"
"jns 5f\n"
"testl $0x200, %1\n\t" /* interrupts were disabled? */
"jz 4f\n\t"
"sti\n"
"3:\t"
"rep;nop\n\t"
"cmpl $0, %0\n\t"
"jle 3b\n\t"
"cli\n\t"
"jmp 1b\n"
"4:\t"
"rep;nop\n\t"
"cmpl $0, %0\n\t"
"jg 1b\n\t"
"jmp 4b\n"
"5:\n\t"
: "+m" (lock->slock) : "r" ((unsigned)flags) : "memory");
}
#endif
static inline int __raw_spin_trylock(raw_spinlock_t *lock)
{
......
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