Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8bdd1d12 authored by Serge E. Hallyn's avatar Serge E. Hallyn Committed by Linus Torvalds
Browse files

[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: default avatarSerge E. Hallyn <serue@us.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 2b943cf0

kernel/stop_machine.c

+11 −6
Original line number Diff line number Diff line
@@ -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++;

	}