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authorStephane Eranian <eranian@hpl.hp.com>2007-02-13 13:26:22 +0100
committerAndi Kleen <andi@basil.nowhere.org>2007-02-13 13:26:22 +0100
commit2ff2d3d74705d34ab71b21f54634fcf50d57bdd5 (patch)
treeb74849c0a55f3eb4458e7399c6d30a0f8b270d58 /include
parent86a978837ca739842317c4cf433de36aeb85ea3b (diff)
[PATCH] i386: add idle notifier
Add a notifier mechanism to the low level idle loop. You can register a callback function which gets invoked on entry and exit from the low level idle loop. The low level idle loop is defined as the polling loop, low-power call, or the mwait instruction. Interrupts processed by the idle thread are not considered part of the low level loop. The notifier can be used to measure precisely how much is spent in useless execution (or low power mode). The perfmon subsystem uses it to turn on/off monitoring. Signed-off-by: stephane eranian <eranian@hpl.hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'include')
-rw-r--r--include/asm-i386/idle.h14
-rw-r--r--include/asm-i386/processor.h8
2 files changed, 22 insertions, 0 deletions
diff --git a/include/asm-i386/idle.h b/include/asm-i386/idle.h
new file mode 100644
index 00000000000..87ab9391119
--- /dev/null
+++ b/include/asm-i386/idle.h
@@ -0,0 +1,14 @@
+#ifndef _ASM_I386_IDLE_H
+#define _ASM_I386_IDLE_H 1
+
+#define IDLE_START 1
+#define IDLE_END 2
+
+struct notifier_block;
+void idle_notifier_register(struct notifier_block *n);
+void idle_notifier_unregister(struct notifier_block *n);
+
+void exit_idle(void);
+void enter_idle(void);
+
+#endif
diff --git a/include/asm-i386/processor.h b/include/asm-i386/processor.h
index 11bf899de8a..edfbe46a5e1 100644
--- a/include/asm-i386/processor.h
+++ b/include/asm-i386/processor.h
@@ -257,6 +257,14 @@ 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);
/* from system description table in BIOS. Mostly for MCA use, but