[PATCH] Light weight event counters

[linux-2.6.git] / drivers / parisc / led.c

diff --git a/drivers/parisc/led.c b/drivers/parisc/led.c
index 95bd07b8b61b6b00cab94a447a2822f5a7e69e19..d7024c7483bd8c8ae83f7d62a1dea7e1aaa0da67 100644 (file)
--- a/drivers/parisc/led.c
+++ b/drivers/parisc/led.c
@@ -3,7 +3,7 @@
  *
  *      (c) Copyright 2000 Red Hat Software
  *      (c) Copyright 2000 Helge Deller <hdeller@redhat.com>
- *      (c) Copyright 2001-2004 Helge Deller <deller@gmx.de>
+ *      (c) Copyright 2001-2005 Helge Deller <deller@gmx.de>
  *      (c) Copyright 2001 Randolph Chung <tausq@debian.org>
  *
  *      This program is free software; you can redistribute it and/or modify
@@ -30,6 +30,7 @@
 #include <linux/types.h>
 #include <linux/ioport.h>
 #include <linux/utsname.h>
+#include <linux/capability.h>
 #include <linux/delay.h>
 #include <linux/netdevice.h>
 #include <linux/inetdevice.h>
@@ -56,13 +57,13 @@
    relatively large amount of CPU time, some of the calculations can be 
    turned off with the following variables (controlled via procfs) */
 
-static int led_type = -1;
+static int led_type __read_mostly = -1;
 static unsigned char lastleds; /* LED state from most recent update */
-static unsigned int led_heartbeat = 1;
-static unsigned int led_diskio = 1;
-static unsigned int led_lanrxtx = 1;
-static char lcd_text[32];
-static char lcd_text_default[32];
+static unsigned int led_heartbeat __read_mostly = 1;
+static unsigned int led_diskio    __read_mostly = 1;
+static unsigned int led_lanrxtx   __read_mostly = 1;
+static char lcd_text[32]          __read_mostly;
+static char lcd_text_default[32]  __read_mostly;
 
 
 static struct workqueue_struct *led_wq;
@@ -108,7 +109,7 @@ struct pdc_chassis_lcd_info_ret_block {
 /* lcd_info is pre-initialized to the values needed to program KittyHawk LCD's 
  * HP seems to have used Sharp/Hitachi HD44780 LCDs most of the time. */
 static struct pdc_chassis_lcd_info_ret_block
-lcd_info __attribute__((aligned(8))) =
+lcd_info __attribute__((aligned(8))) __read_mostly =
 {
        .model =                DISPLAY_MODEL_LCD,
        .lcd_width =            16,
@@ -144,7 +145,7 @@ static int start_task(void)
 device_initcall(start_task);
 
 /* ptr to LCD/LED-specific function */
-static void (*led_func_ptr) (unsigned char);
+static void (*led_func_ptr) (unsigned char) __read_mostly;
 
 #ifdef CONFIG_PROC_FS
 static int led_proc_read(char *page, char **start, off_t off, int count, 
@@ -347,7 +348,7 @@ static void led_LCD_driver(unsigned char leds)
    ** 
    ** led_get_net_activity()
    ** 
-   ** calculate if there was TX- or RX-troughput on the network interfaces
+   ** calculate if there was TX- or RX-throughput on the network interfaces
    ** (analog to dev_get_info() from net/core/dev.c)
    **   
  */
@@ -410,16 +411,17 @@ static __inline__ int led_get_net_activity(void)
 static __inline__ int led_get_diskio_activity(void)
 {      
        static unsigned long last_pgpgin, last_pgpgout;
-       struct page_state pgstat;
+       unsigned long events[NR_VM_EVENT_ITEMS];
        int changed;
 
-       get_full_page_state(&pgstat); /* get no of sectors in & out */
+       all_vm_events(events);
 
        /* Just use a very simple calculation here. Do not care about overflow,
           since we only want to know if there was activity or not. */
-       changed = (pgstat.pgpgin != last_pgpgin) || (pgstat.pgpgout != last_pgpgout);
-       last_pgpgin  = pgstat.pgpgin;
-       last_pgpgout = pgstat.pgpgout;
+       changed = (events[PGPGIN] != last_pgpgin) ||
+                 (events[PGPGOUT] != last_pgpgout);
+       last_pgpgin  = events[PGPGIN];
+       last_pgpgout = events[PGPGOUT];
 
        return (changed ? LED_DISK_IO : 0);
 }
@@ -498,11 +500,16 @@ static int led_halt(struct notifier_block *, unsigned long, void *);
 static struct notifier_block led_notifier = {
        .notifier_call = led_halt,
 };
+static int notifier_disabled = 0;
 
 static int led_halt(struct notifier_block *nb, unsigned long event, void *buf) 
 {
        char *txt;
-       
+
+       if (notifier_disabled)
+               return NOTIFY_OK;
+
+       notifier_disabled = 1;
        switch (event) {
        case SYS_RESTART:       txt = "SYSTEM RESTART";
                                break;
@@ -526,7 +533,6 @@ static int led_halt(struct notifier_block *nb, unsigned long event, void *buf)
                if (led_func_ptr)
                        led_func_ptr(0xff); /* turn all LEDs ON */
        
-       unregister_reboot_notifier(&led_notifier);
        return NOTIFY_OK;
 }
 
@@ -757,6 +763,12 @@ not_found:
        return 1;
 }
 
+static void __exit led_exit(void)
+{
+       unregister_reboot_notifier(&led_notifier);
+       return;
+}
+
 #ifdef CONFIG_PROC_FS
 module_init(led_create_procfs)
 #endif