Re: PATCH: Create new LED trigger for CPU activity (ledtrig-cpu) (UPDATED)

["Thomas Tuttle" <thinkinginbinary@gmail.com>]

Here is a new version of the patch, incorporating code style tips from
Randy Dunlap <rdunlap@xenotime.net>, and based on 2.6.17-git25, rather
than 2.6.17.1.

I noticed that there's a Heartbeat LED trigger in the git version.  I
hope this isn't too similar.

--
Thomas Tuttle
http://thinkinginbinary.webhop.net/
thinkinginbinary@gmail.com
AIM: thinkinginbinary

diff -udrN linux-2.6.17-git25/drivers/leds/Kconfig linux-2.6.17-git25-mine/drivers/leds/Kconfig
--- linux-2.6.17-git25/drivers/leds/Kconfig	2006-07-05 22:11:45.000000000 -0400
+++ linux-2.6.17-git25-mine/drivers/leds/Kconfig	2006-07-05 22:42:58.000000000 -0400
@@ -93,6 +93,41 @@
 	  This allows LEDs to be controlled by IDE disk activity.
 	  If unsure, say Y.
 
+config LEDS_TRIGGER_CPU
+	tristate "LED CPU Trigger"
+	depends LEDS_TRIGGERS
+	help
+	  This allows LEDs to be controlled by CPU activity.
+	  If unsure, say Y.
+
+config LEDS_TRIGGER_CPU_INCLUDE_USER
+	bool "Include user time in CPU trigger"
+	depends LEDS_TRIGGER_CPU
+	default y
+	help
+	  This option makes user CPU time cause the CPU trigger to activate.
+
+config LEDS_TRIGGER_CPU_INCLUDE_NICE
+	bool "Include nice time in CPU trigger"
+	depends LEDS_TRIGGER_CPU
+	default n
+	help
+	  This option makes nice CPU time cause the CPU trigger to activate.
+
+config LEDS_TRIGGER_CPU_INCLUDE_SYSTEM
+	bool "Include system time in CPU trigger"
+	depends LEDS_TRIGGER_CPU
+	default y
+	help
+	  This option makes system CPU time cause the CPU trigger to activate.
+
+config LEDS_TRIGGER_CPU_INCLUDE_IOWAIT
+	bool "Include iowait time in CPU trigger"
+	depends LEDS_TRIGGER_CPU
+	default n
+	help
+	  This option makes iowait CPU time cause the CPU trigger to activate.
+
 config LEDS_TRIGGER_HEARTBEAT
 	tristate "LED Heartbeat Trigger"
 	depends LEDS_TRIGGERS
diff -udrN linux-2.6.17-git25/drivers/leds/ledtrig-cpu.c linux-2.6.17-git25-mine/drivers/leds/ledtrig-cpu.c
--- linux-2.6.17-git25/drivers/leds/ledtrig-cpu.c	1969-12-31 19:00:00.000000000 -0500
+++ linux-2.6.17-git25-mine/drivers/leds/ledtrig-cpu.c	2006-07-05 22:42:38.000000000 -0400
@@ -0,0 +1,87 @@
+/*
+ * LED CPU Activity Trigger
+ *
+ * Copyright 2006 Thomas Tuttle
+ *
+ * Author: Thomas Tuttle <thinkinginbinary@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <linux/leds.h>
+#include <linux/kernel_stat.h>
+#include <asm/cputime.h>
+
+#define UPDATE_INTERVAL (5) /* delay between updates, in ms */
+
+static void ledtrig_cpu_timerfunc(unsigned long data);
+
+DEFINE_LED_TRIGGER(ledtrig_cpu);
+static DEFINE_TIMER(ledtrig_cpu_timer, ledtrig_cpu_timerfunc, 0, 0);
+
+static cputime64_t cpu_usage(void)
+{
+	int i;
+	cputime64_t time = cputime64_zero;
+
+	for_each_possible_cpu(i) {
+#ifdef CONFIG_LEDS_TRIGGER_CPU_INCLUDE_USER
+		time = cputime64_add(time, kstat_cpu(i).cpustat.user);
+#endif
+#ifdef CONFIG_LEDS_TRIGGER_CPU_INCLUDE_NICE
+		time = cputime64_add(time, kstat_cpu(i).cpustat.nice);
+#endif
+#ifdef CONFIG_LEDS_TRIGGER_CPU_INCLUDE_SYSTEM
+		time = cputime64_add(time, kstat_cpu(i).cpustat.system);
+#endif
+#ifdef CONFIG_LEDS_TRIGGER_CPU_INCLUDE_IOWAIT
+		time = cputime64_add(time, kstat_cpu(i).cpustat.iowait);
+#endif
+	}
+
+	return time;
+}
+
+cputime64_t last_cputime;
+
+static void ledtrig_cpu_timerfunc(unsigned long data)
+{
+	cputime64_t this_cputime = cpu_usage();
+	/* XXX: This assumes that cputime64_t can be subtracted.
+	 * Nobody has defined cputime64_sub, so I had to do this instead. */
+	cputime64_t used_cputime = this_cputime - last_cputime;
+	enum led_brightness led_state = (used_cputime > 0) ? LED_FULL : LED_OFF;
+	led_trigger_event(ledtrig_cpu, led_state);
+	last_cputime = cpu_usage();
+
+	mod_timer(&ledtrig_cpu_timer, jiffies + msecs_to_jiffies(UPDATE_INTERVAL));
+}
+
+static int __init ledtrig_cpu_init(void)
+{
+	led_trigger_register_simple("cpu", &ledtrig_cpu);
+	last_cputime = cpu_usage();
+	mod_timer(&ledtrig_cpu_timer, jiffies + msecs_to_jiffies(UPDATE_INTERVAL));
+	return 0;
+}
+
+static void __exit ledtrig_cpu_exit(void)
+{
+	del_timer(&ledtrig_cpu_timer);
+	led_trigger_unregister_simple(ledtrig_cpu);
+}
+
+module_init(ledtrig_cpu_init);
+module_exit(ledtrig_cpu_exit);
+
+MODULE_AUTHOR("Thomas Tuttle <thinkinginbinary@gmail.com>");
+MODULE_DESCRIPTION("LED CPU Activity Trigger");
+MODULE_LICENSE("GPL");
diff -udrN linux-2.6.17-git25/drivers/leds/Makefile linux-2.6.17-git25-mine/drivers/leds/Makefile
--- linux-2.6.17-git25/drivers/leds/Makefile	2006-07-05 22:11:45.000000000 -0400
+++ linux-2.6.17-git25-mine/drivers/leds/Makefile	2006-07-05 22:40:52.000000000 -0400
@@ -16,4 +16,5 @@
 # LED Triggers
 obj-$(CONFIG_LEDS_TRIGGER_TIMER)	+= ledtrig-timer.o
 obj-$(CONFIG_LEDS_TRIGGER_IDE_DISK)	+= ledtrig-ide-disk.o
+obj-$(CONFIG_LEDS_TRIGGER_CPU)		+= ledtrig-cpu.o
 obj-$(CONFIG_LEDS_TRIGGER_HEARTBEAT)	+= ledtrig-heartbeat.o