From: Keith Owens <kaos@sgi.com>
Date: Sun, 11 Sep 2005 07:19:06 +0000 (+1000)
Subject: [PATCH] MCA/INIT: scheduler hooks
X-Git-Tag: v2.6.14-rc1~111^2~7
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=a2a979821b6ab75a4f143cfaa1c4672cc259ec10;p=linux-2.6-omap-h63xx.git

[PATCH] MCA/INIT: scheduler hooks

Scheduler hooks to see/change which process is deemed to be on a cpu.

Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
---

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 4b83cb23000..ed3bb19d133 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -904,6 +904,8 @@ extern int task_curr(const task_t *p);
 extern int idle_cpu(int cpu);
 extern int sched_setscheduler(struct task_struct *, int, struct sched_param *);
 extern task_t *idle_task(int cpu);
+extern task_t *curr_task(int cpu);
+extern void set_curr_task(int cpu, task_t *p);
 
 void yield(void);
 
diff --git a/kernel/sched.c b/kernel/sched.c
index dbd4490afec..e9ff04a9b56 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3576,6 +3576,32 @@ task_t *idle_task(int cpu)
 	return cpu_rq(cpu)->idle;
 }
 
+/**
+ * curr_task - return the current task for a given cpu.
+ * @cpu: the processor in question.
+ */
+task_t *curr_task(int cpu)
+{
+	return cpu_curr(cpu);
+}
+
+/**
+ * set_curr_task - set the current task for a given cpu.
+ * @cpu: the processor in question.
+ * @p: the task pointer to set.
+ *
+ * Description: This function must only be used when non-maskable interrupts
+ * are serviced on a separate stack.  It allows the architecture to switch the
+ * notion of the current task on a cpu in a non-blocking manner.  This function
+ * must be called with interrupts disabled, the caller must save the original
+ * value of the current task (see curr_task() above) and restore that value
+ * before reenabling interrupts.
+ */
+void set_curr_task(int cpu, task_t *p)
+{
+	cpu_curr(cpu) = p;
+}
+
 /**
  * find_process_by_pid - find a process with a matching PID value.
  * @pid: the pid in question.