[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 <venkatesh.pallipadi@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
diff --git a/include/asm-x86_64/processor.h b/include/asm-x86_64/processor.h
index cef17e0..76552d7 100644
--- a/include/asm-x86_64/processor.h
+++ b/include/asm-x86_64/processor.h
@@ -475,6 +475,14 @@
: :"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() \