This commit was manufactured by cvs2svn to create tag

[linux-2.6.git] / kernel / cpu.c

diff --git a/kernel/cpu.c b/kernel/cpu.c
index ebaba87..719ba42 100644 (file)
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -11,6 +11,7 @@
 #include <linux/unistd.h>
 #include <linux/cpu.h>
 #include <linux/module.h>
+#include <linux/kmod.h>                /* for hotplug_path */
 #include <linux/kthread.h>
 #include <linux/stop_machine.h>
 #include <asm/semaphore.h>
@@ -56,6 +57,34 @@ static inline void check_for_tasks(int cpu)
        write_unlock_irq(&tasklist_lock);
 }
 
+/* Notify userspace when a cpu event occurs, by running '/sbin/hotplug
+ * cpu' with certain environment variables set.  */
+static int cpu_run_sbin_hotplug(unsigned int cpu, const char *action)
+{
+       char *argv[3], *envp[6], cpu_str[12], action_str[32], devpath_str[40];
+       int i;
+
+       sprintf(cpu_str, "CPU=%d", cpu);
+       sprintf(action_str, "ACTION=%s", action);
+       sprintf(devpath_str, "DEVPATH=devices/system/cpu/cpu%d", cpu);
+       
+       i = 0;
+       argv[i++] = hotplug_path;
+       argv[i++] = "cpu";
+       argv[i] = NULL;
+
+       i = 0;
+       /* minimal command environment */
+       envp[i++] = "HOME=/";
+       envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
+       envp[i++] = cpu_str;
+       envp[i++] = action_str;
+       envp[i++] = devpath_str;
+       envp[i] = NULL;
+
+       return call_usermodehelper(argv[0], argv, envp, 0);
+}
+
 /* Take this CPU down. */
 static int take_cpu_down(void *unused)
 {
@@ -141,6 +170,8 @@ int cpu_down(unsigned int cpu)
 
        check_for_tasks(cpu);
 
+       cpu_run_sbin_hotplug(cpu, "offline");
+
 out_thread:
        err = kthread_stop(p);
 out_allowed:
@@ -149,6 +180,11 @@ out:
        unlock_cpu_hotplug();
        return err;
 }
+#else
+static inline int cpu_run_sbin_hotplug(unsigned int cpu, const char *action)
+{
+       return 0;
+}
 #endif /*CONFIG_HOTPLUG_CPU*/
 
 int __devinit cpu_up(unsigned int cpu)