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

Commit e7407dcc authored by Heiko Carstens's avatar Heiko Carstens Committed by Linus Torvalds
Browse files

call cpu_chain with CPU_DOWN_FAILED if CPU_DOWN_PREPARE failed 



This makes cpu hotplug symmetrical: if CPU_UP_PREPARE fails we get
CPU_UP_CANCELED, so we can undo what ever happened on PREPARE.  The same
should happen for CPU_DOWN_PREPARE.

[akpm@linux-foundation.org: fix for reduce-size-of-task_struct-on-64-bit-machines]
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Gautham Shenoy <ego@in.ibm.com>
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5be9361c

kernel/cpu.c

+10 −9
Original line number Diff line number Diff line
@@ -97,7 +97,7 @@ static inline void check_for_tasks(int cpu) 
		    (!cputime_eq(p->utime, cputime_zero) ||

		     !cputime_eq(p->stime, cputime_zero)))

			printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d\

				(state = %ld, flags = %lx) \n",

				(state = %ld, flags = %x) \n",

				 p->comm, p->pid, cpu, p->state, p->flags);

	}

	write_unlock_irq(&tasklist_lock);
@@ -122,9 +122,10 @@ static int take_cpu_down(void *unused) 
/* Requires cpu_add_remove_lock to be held */

static int _cpu_down(unsigned int cpu)

{

	int err;

	int err, nr_calls = 0;

	struct task_struct *p;

	cpumask_t old_allowed, tmp;

	void *hcpu = (void *)(long)cpu;



	if (num_online_cpus() == 1)

		return -EBUSY;
@@ -132,11 +133,12 @@ static int _cpu_down(unsigned int cpu) 
	if (!cpu_online(cpu))

		return -EINVAL;



	raw_notifier_call_chain(&cpu_chain, CPU_LOCK_ACQUIRE,

						(void *)(long)cpu);

	err = raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE,

						(void *)(long)cpu);

	raw_notifier_call_chain(&cpu_chain, CPU_LOCK_ACQUIRE, hcpu);

	err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE,

					hcpu, -1, &nr_calls);

	if (err == NOTIFY_BAD) {

		__raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED, hcpu,

					  nr_calls, NULL);

		printk("%s: attempt to take down CPU %u failed\n",

				__FUNCTION__, cpu);

		err = -EINVAL;
@@ -156,7 +158,7 @@ static int _cpu_down(unsigned int cpu) 
	if (IS_ERR(p) || cpu_online(cpu)) {

		/* CPU didn't die: tell everyone.  Can't complain. */

		if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED,

				(void *)(long)cpu) == NOTIFY_BAD)

					    hcpu) == NOTIFY_BAD)

			BUG();



		if (IS_ERR(p)) {
@@ -178,8 +180,7 @@ static int _cpu_down(unsigned int cpu) 
	put_cpu();



	/* CPU is completely dead: tell everyone.  Too late to complain. */

	if (raw_notifier_call_chain(&cpu_chain, CPU_DEAD,

			(void *)(long)cpu) == NOTIFY_BAD)

	if (raw_notifier_call_chain(&cpu_chain, CPU_DEAD, hcpu) == NOTIFY_BAD)

		BUG();



	check_for_tasks(cpu);