Cset exclude: mingo@elte.hu|ChangeSet|20020728030719|07783

init/main.c

@@ -526,14 +526,10 @@ static void __init do_basic_setup(void)
 
 static void do_pre_smp_initcalls(void)
 {
-#if CONFIG_SMP
 	extern int migration_init(void);
-#endif
 	extern int spawn_ksoftirqd(void);
 
-#if CONFIG_SMP
 	migration_init();
-#endif
 	spawn_ksoftirqd();
 }
 

kernel/sched.c

@@ -16,23 +16,19 @@
  *		by Davide Libenzi, preemptible kernel bits by Robert Love.
  */
 
-#define __KERNEL_SYSCALLS__
-
 #include <linux/mm.h>
 #include <linux/nmi.h>
 #include <linux/init.h>
-#include <linux/delay.h>
-#include <linux/unistd.h>
+#include <asm/uaccess.h>
 #include <linux/highmem.h>
-#include <linux/security.h>
-#include <linux/notifier.h>
 #include <linux/smp_lock.h>
+#include <asm/mmu_context.h>
 #include <linux/interrupt.h>
 #include <linux/completion.h>
 #include <linux/kernel_stat.h>
-
-#include <asm/uaccess.h>
-#include <asm/mmu_context.h>
+#include <linux/security.h>
+#include <linux/notifier.h>
+#include <linux/delay.h>
 
 /*
  * Convert user-nice values [ -20 ... 0 ... 19 ]
@@ -1961,29 +1957,6 @@ void set_cpus_allowed(task_t *p, unsigned long new_mask)
 	preempt_enable();
 }
 
-/*
- * The migration thread startup relies on the following property
- * of set_cpus_allowed(): if the thread is not running currently
- * then we can just put it into the target runqueue.
- */
-DECLARE_MUTEX_LOCKED(migration_startup);
-
-typedef struct migration_startup_data {
-	int cpu;
-	task_t *thread;
-} migration_startup_t;
-
-static int migration_startup_thread(void * data)
-{
-	migration_startup_t *startup = data;
-
-	wait_task_inactive(startup->thread);
-	set_cpus_allowed(startup->thread, 1UL << startup->cpu);
-	up(&migration_startup);
-
-	return 0;
-}
-
 /*
  * migration_thread - this is a highprio system thread that performs
  * thread migration by 'pulling' threads into the target runqueue.
@@ -1991,19 +1964,15 @@ static int migration_startup_thread(void * data)
 static int migration_thread(void * data)
 {
 	struct sched_param param = { sched_priority: MAX_RT_PRIO-1 };
-	migration_startup_t startup;
 	int cpu = (long) data;
 	runqueue_t *rq;
-	int ret, pid;
+	int ret;
 
 	daemonize();
 	sigfillset(&current->blocked);
 	set_fs(KERNEL_DS);
 
-	startup.cpu = cpu;
-	startup.thread = current;
-	pid = kernel_thread(migration_startup_thread, &startup,
-		CLONE_FS | CLONE_FILES | CLONE_SIGNAL);
+	set_cpus_allowed(current, 1UL << cpu);
 
 	/*
 	 * Migration can happen without a migration thread on the
@@ -2011,18 +1980,7 @@ static int migration_thread(void * data)
 	 * runqueue and the helper thread then moves this thread
 	 * to the target CPU - we'll wake up there.
 	 */
-	down(&migration_startup);
-
-	/* we need to waitpid() to release the helper thread */
-	waitpid(pid, NULL, __WCLONE);
-
-	/*
-	 * At this point the startup helper thread must have
-	 * migrated us to the proper CPU already:
-	 */
 	if (smp_processor_id() != cpu)
-		BUG();
-
 	printk("migration_task %d on cpu=%d\n", cpu, smp_processor_id());
 	ret = setscheduler(0, SCHED_FIFO, &param);
 
@@ -2087,14 +2045,13 @@ static int migration_call(struct notifier_block *nfb,
 			  unsigned long action,
 			  void *hcpu)
 {
-	unsigned long cpu = (unsigned long)hcpu;
-
 	switch (action) {
 	case CPU_ONLINE:
-		printk("Starting migration thread for cpu %li\n", cpu);
-		kernel_thread(migration_thread, (void *)cpu,
+		printk("Starting migration thread for cpu %li\n",
+		       (long)hcpu);
+		kernel_thread(migration_thread, hcpu,
 			      CLONE_FS | CLONE_FILES | CLONE_SIGNAL);
-		while (!cpu_rq(cpu)->migration_thread)
+		while (!cpu_rq((long)hcpu)->migration_thread)
 			yield();
 		break;
 	}