[RFC PATCH 03/20] Idle notifier standardization

Mathieu Desnoyers
2010-08-17T23:23:19Z

[-- Attachment #1: idle-notifier-standardize.patch --]
[-- Type: text/plain, Size: 5409 bytes --]

Move idle notifiers into arch-agnostic code. Adapt x86 64 accordingly to call
the new architecture-agnostic notifiers rather than its own. Other architectures
are still "todo".

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
arch/x86/include/asm/idle.h | 7 -------
arch/x86/kernel/process_64.c | 19 +++----------------
drivers/idle/i7300_idle.c | 5 +++--
include/linux/idle.h | 19 +++++++++++++++++++
kernel/notifier.c | 25 +++++++++++++++++++++++++
5 files changed, 50 insertions(+), 25 deletions(-)

Index: linux.trees.git/arch/x86/kernel/process_64.c
===================================================================
--- linux.trees.git.orig/arch/x86/kernel/process_64.c 2010-06-25 15:12:56.000000000 -0400
+++ linux.trees.git/arch/x86/kernel/process_64.c 2010-06-25 15:12:59.000000000 -0400
@@ -35,6 +35,7 @@
#include <linux/tick.h>
#include <linux/prctl.h>
#include <linux/uaccess.h>
+#include <linux/idle.h>
#include <linux/io.h>
#include <linux/ftrace.h>

@@ -58,31 +59,17 @@ asmlinkage extern void ret_from_fork(voi
DEFINE_PER_CPU(unsigned long, old_rsp);
static DEFINE_PER_CPU(unsigned char, is_idle);

-static ATOMIC_NOTIFIER_HEAD(idle_notifier);
-
-void idle_notifier_register(struct notifier_block *n)
-{
- atomic_notifier_chain_register(&idle_notifier, n);
-}
-EXPORT_SYMBOL_GPL(idle_notifier_register);
-
-void idle_notifier_unregister(struct notifier_block *n)
-{
- atomic_notifier_chain_unregister(&idle_notifier, n);
-}
-EXPORT_SYMBOL_GPL(idle_notifier_unregister);
-
void enter_idle(void)
{
percpu_write(is_idle, 1);
- atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL);
+ notify_idle(IDLE_START);
}

static void __exit_idle(void)
{
if (x86_test_and_clear_bit_percpu(0, is_idle) == 0)
return;
- atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL);
+ notify_idle(IDLE_END);
}

/* Called from interrupts to signify idle end */
Index: linux.trees.git/arch/x86/include/asm/idle.h
===================================================================
--- linux.trees.git.orig/arch/x86/include/asm/idle.h 2010-06-25 15:12:56.000000000 -0400
+++ linux.trees.git/arch/x86/include/asm/idle.h 2010-06-25 15:12:59.000000000 -0400
@@ -1,13 +1,6 @@
#ifndef _ASM_X86_IDLE_H
#define _ASM_X86_IDLE_H

-#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);
-
#ifdef CONFIG_X86_64
void enter_idle(void);
void exit_idle(void);
Index: linux.trees.git/include/linux/idle.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux.trees.git/include/linux/idle.h 2010-06-25 15:12:59.000000000 -0400
@@ -0,0 +1,19 @@
+/*
+ * include/linux/idle.h - generic idle definition
+ *
+ */
+#ifndef _LINUX_IDLE_H_
+#define _LINUX_IDLE_H_
+
+#include <linux/notifier.h>
+
+enum idle_val {
+ IDLE_START = 1,
+ IDLE_END = 2,
+};
+
+int notify_idle(enum idle_val val);
+void register_idle_notifier(struct notifier_block *n);
+void unregister_idle_notifier(struct notifier_block *n);
+
+#endif /* _LINUX_IDLE_H_ */
Index: linux.trees.git/kernel/notifier.c
===================================================================
--- linux.trees.git.orig/kernel/notifier.c 2010-06-25 15:12:59.000000000 -0400
+++ linux.trees.git/kernel/notifier.c 2010-06-25 15:12:59.000000000 -0400
@@ -5,6 +5,7 @@
#include <linux/rcupdate.h>
#include <linux/vmalloc.h>
#include <linux/reboot.h>
+#include <linux/idle.h>

/*
* Notifier list for kernel code which wants to be called
@@ -584,3 +585,27 @@ int unregister_die_notifier(struct notif
return atomic_notifier_chain_unregister(&die_chain, nb);
}
EXPORT_SYMBOL_GPL(unregister_die_notifier);
+
+static ATOMIC_NOTIFIER_HEAD(idle_notifier);
+
+/*
+ * Trace last event before calling notifiers. Notifiers flush data from buffers
+ * before going to idle.
+ */
+int notrace notify_idle(enum idle_val val)
+{
+ return atomic_notifier_call_chain(&idle_notifier, val, NULL);
+}
+EXPORT_SYMBOL_GPL(notify_idle);
+
+void register_idle_notifier(struct notifier_block *n)
+{
+ atomic_notifier_chain_register(&idle_notifier, n);
+}
+EXPORT_SYMBOL_GPL(register_idle_notifier);
+
+void unregister_idle_notifier(struct notifier_block *n)
+{
+ atomic_notifier_chain_unregister(&idle_notifier, n);
+}
+EXPORT_SYMBOL_GPL(unregister_idle_notifier);
Index: linux.trees.git/drivers/idle/i7300_idle.c
===================================================================
--- linux.trees.git.orig/drivers/idle/i7300_idle.c 2010-06-19 16:08:34.000000000 -0400
+++ linux.trees.git/drivers/idle/i7300_idle.c 2010-06-25 15:13:11.000000000 -0400
@@ -27,6 +27,7 @@
#include <linux/debugfs.h>
#include <linux/stop_machine.h>
#include <linux/i7300_idle.h>
+#include <linux/idle.h>

#include <asm/idle.h>

@@ -583,7 +584,7 @@ static int __init i7300_idle_init(void)
}
}

- idle_notifier_register(&i7300_idle_nb);
+ register_idle_notifier(&i7300_idle_nb);

printk(KERN_INFO "i7300_idle: loaded v%s\n", I7300_IDLE_DRIVER_VERSION);
return 0;
@@ -591,7 +592,7 @@ static int __init i7300_idle_init(void)

static void __exit i7300_idle_exit(void)
{
- idle_notifier_unregister(&i7300_idle_nb);
+ unregister_idle_notifier(&i7300_idle_nb);
free_cpumask_var(idle_cpumask);

if (debugfs_dir) {