From d331e739f5ad2aaa9d8553891ba6ca823bdbce37 Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Thu, 7 Dec 2006 02:14:13 +0100 Subject: [PATCH] x86-64: Fix interrupt race in idle callback (3rd try) Idle callbacks has some races when enter_idle() sets isidle and subsequent interrupts that can happen on that CPU, before CPU goes to idle. Due to this, an IDLE_END can get called before IDLE_START. To avoid these races, disable interrupts before enter_idle and make sure that all idle routines do not enable interrupts before entering idle. Note that poll_idle() still has a this race as it has to enable interrupts before going to idle. But, all other idle routines have the race fixed. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Andi Kleen --- include/asm-x86_64/processor.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include') diff --git a/include/asm-x86_64/processor.h b/include/asm-x86_64/processor.h index cef17e0f828..76552d72804 100644 --- a/include/asm-x86_64/processor.h +++ b/include/asm-x86_64/processor.h @@ -475,6 +475,14 @@ static inline void __mwait(unsigned long eax, unsigned long ecx) : :"a" (eax), "c" (ecx)); } +static inline void __sti_mwait(unsigned long eax, unsigned long ecx) +{ + /* "mwait %eax,%ecx;" */ + asm volatile( + "sti; .byte 0x0f,0x01,0xc9;" + : :"a" (eax), "c" (ecx)); +} + extern void mwait_idle_with_hints(unsigned long eax, unsigned long ecx); #define stack_current() \ -- cgit v1.2.3