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[PATCH] kthread: convert stop_machine into a kthread

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- 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>
This commit is contained in:
Serge E. Hallyn 2006-06-25 05:49:08 -07:00 committed by Linus Torvalds
parent 2b943cf09d
commit 8bdd1d1250
1 changed files with 11 additions and 6 deletions
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17
kernel/stop_machine.c
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@ -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 unsigned int stopmachine_num_threads;
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 void stopmachine_set_state(enum stopmachine_state state)
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 @@ static int stop_machine(void)
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++;
}