[PATCH] set TASK_RUNNING in yield()

It seems that the yield() macro requires state TASK_RUNNING, but
practically none of the callers remember to do that.

The patch turns yield() into a real function which sets state
TASK_RUNNING before scheduling.

drivers/net/e100/e100.h

@@ -1031,14 +1031,6 @@ extern unsigned char e100_selftest(struct e100_private *bdp, u32 *st_timeout,
 extern unsigned char e100_get_link_state(struct e100_private *bdp);
 extern unsigned char e100_wait_scb(struct e100_private *bdp);
 
-#ifndef yield
-#define yield()					\
-        do {					\
-                current->policy |= SCHED_YIELD;	\
-                schedule();			\
-        } while (0)                                     
-#endif
-
 extern void e100_deisolate_driver(struct e100_private *bdp,
 				  u8 recover, u8 full_reset);
 extern unsigned char e100_hw_reset_recover(struct e100_private *bdp,

fs/buffer.c

@@ -494,7 +494,6 @@ static void free_more_memory(void)
 	wakeup_bdflush();
 	try_to_free_pages(zone, GFP_NOFS, 0);
 	blk_run_queues();
-	__set_current_state(TASK_RUNNING);
 	yield();
 }
 

include/linux/sched.h

@@ -418,8 +418,7 @@ extern int task_prio(task_t *p);
 extern int task_nice(task_t *p);
 extern int idle_cpu(int cpu);
 
-asmlinkage long sys_sched_yield(void);
-#define yield() sys_sched_yield()
+void yield(void);
 
 /*
  * The default (Linux) execution domain.

kernel/ksyms.c

@@ -472,7 +472,7 @@ EXPORT_SYMBOL(schedule);
 EXPORT_SYMBOL(preempt_schedule);
 #endif
 EXPORT_SYMBOL(schedule_timeout);
-EXPORT_SYMBOL(sys_sched_yield);
+EXPORT_SYMBOL(yield);
 EXPORT_SYMBOL(__cond_resched);
 EXPORT_SYMBOL(set_user_nice);
 EXPORT_SYMBOL(task_nice);

kernel/sched.c

@@ -1453,6 +1453,12 @@ void __cond_resched(void)
 	schedule();
 }
 
+void yield(void)
+{
+	set_current_state(TASK_RUNNING);
+	sys_sched_yield();
+}
+
 asmlinkage long sys_sched_get_priority_max(int policy)
 {
 	int ret = -EINVAL;

kernel/softirq.c

@@ -262,7 +262,6 @@ void tasklet_kill(struct tasklet_struct *t)
 		printk("Attempt to kill tasklet from interrupt\n");
 
 	while (test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) {
-		current->state = TASK_RUNNING;
 		do
 			yield();
 		while (test_bit(TASKLET_STATE_SCHED, &t->state));

kernel/suspend.c

@@ -237,8 +237,7 @@ int freeze_processes(void)
 			todo++;
 		}
 		read_unlock(&tasklist_lock);
-		sys_sched_yield();
-		schedule();
+		yield();
 		if (time_after(jiffies, start_time + TIMEOUT)) {
 			PRINTK( "\n" );
 			printk(KERN_ERR " stopping tasks failed (%d tasks remaining)\n", todo );

mm/page_alloc.c

@@ -441,7 +441,6 @@ struct page * __alloc_pages(unsigned int gfp_mask, unsigned int order, zonelist_
 		goto nopage;
 
 	/* Yield for kswapd, and try again */
-	__set_current_state(TASK_RUNNING);
 	yield();
 	goto rebalance;
 }