[PATCH] kthread: convert stop_machine into a kthread
- Update stop_machine.c to spawn stop_machine as kthreads rather than the
deprecated kernel_threads.
- Update stop_machine to use the more efficient kthread_bind() before
running task in place of set_cpus_allowed() after.
[akpm@osdl.org: remove now-wrong set_cpus_allowed()]
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index dcfb5d7..2c0aacc 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -4,6 +4,7 @@
#include <linux/cpu.h>
#include <linux/err.h>
#include <linux/syscalls.h>
+#include <linux/kthread.h>
#include <asm/atomic.h>
#include <asm/semaphore.h>
#include <asm/uaccess.h>
@@ -25,13 +26,11 @@
static atomic_t stopmachine_thread_ack;
static DECLARE_MUTEX(stopmachine_mutex);
-static int stopmachine(void *cpu)
+static int stopmachine(void *unused)
{
int irqs_disabled = 0;
int prepared = 0;
- set_cpus_allowed(current, cpumask_of_cpu((int)(long)cpu));
-
/* Ack: we are alive */
smp_mb(); /* Theoretically the ack = 0 might not be on this CPU yet. */
atomic_inc(&stopmachine_thread_ack);
@@ -85,7 +84,8 @@
static int stop_machine(void)
{
- int i, ret = 0;
+ int ret = 0;
+ unsigned int i;
struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
/* One high-prio thread per cpu. We'll do this one. */
@@ -96,11 +96,16 @@
stopmachine_state = STOPMACHINE_WAIT;
for_each_online_cpu(i) {
+ struct task_struct *tsk;
if (i == raw_smp_processor_id())
continue;
- ret = kernel_thread(stopmachine, (void *)(long)i,CLONE_KERNEL);
- if (ret < 0)
+ tsk = kthread_create(stopmachine, NULL, "stopmachine");
+ if (IS_ERR(tsk)) {
+ ret = PTR_ERR(tsk);
break;
+ }
+ kthread_bind(tsk, i);
+ wake_up_process(tsk);
stopmachine_num_threads++;
}