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Commit 55db493b authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'cpumask-cleanups' of... 

Merge branch 'cpumask-cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

* 'cpumask-cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  cpumask: rename tsk_cpumask to tsk_cpus_allowed
  cpumask: don't recommend set_cpus_allowed hack in Documentation/cpu-hotplug.txt
  cpumask: avoid dereferencing struct cpumask
  cpumask: convert drivers/idle/i7300_idle.c to cpumask_var_t
  cpumask: use modern cpumask style in drivers/scsi/fcoe/fcoe.c
  cpumask: avoid deprecated function in mm/slab.c
  cpumask: use cpu_online in kernel/perf_event.c
parents efc8e7f4 a4636818

Documentation/cpu-hotplug.txt

+17 −32
Original line number Original line Diff line number Diff line
@@ -315,42 +315,27 @@ A: The following are what is required for CPU hotplug infrastructure to work 




Q: I need to ensure that a particular cpu is not removed when there is some

Q: I need to ensure that a particular cpu is not removed when there is some

   work specific to this cpu is in progress.

   work specific to this cpu is in progress.

A: First switch the current thread context to preferred cpu

A: There are two ways.  If your code can be run in interrupt context, use

   smp_call_function_single(), otherwise use work_on_cpu().  Note that

   work_on_cpu() is slow, and can fail due to out of memory:





	int my_func_on_cpu(int cpu)

	int my_func_on_cpu(int cpu)

	{

	{

		cpumask_t saved_mask, new_mask = CPU_MASK_NONE;

		int err;

		int curr_cpu, err = 0;

		get_online_cpus();



		if (!cpu_online(cpu))

		saved_mask = current->cpus_allowed;

			err = -EINVAL;

		cpu_set(cpu, new_mask);

		else

		err = set_cpus_allowed(current, new_mask);

#if NEEDS_BLOCKING



			err = work_on_cpu(cpu, __my_func_on_cpu, NULL);

		if (err)

#else

			return err;

			smp_call_function_single(cpu, __my_func_on_cpu, &err,



						 true);

		/*

#endif

		 * If we got scheduled out just after the return from

		put_online_cpus();

		 * set_cpus_allowed() before running the work, this ensures

		 * we stay locked.

		 */

		curr_cpu = get_cpu();



		if (curr_cpu != cpu) {

			err = -EAGAIN;

			goto ret;

		} else {

			/*

			 * Do work : But cant sleep, since get_cpu() disables preempt

			 */

		}

		ret:

			put_cpu();

			set_cpus_allowed(current, saved_mask);

		return err;

		return err;

	}

	}







Q: How do we determine how many CPUs are available for hotplug.

Q: How do we determine how many CPUs are available for hotplug.

A: There is no clear spec defined way from ACPI that can give us that

A: There is no clear spec defined way from ACPI that can give us that

   information today. Based on some input from Natalie of Unisys,

   information today. Based on some input from Natalie of Unisys,

arch/x86/kernel/cpu/cpufreq/powernow-k8.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -1136,7 +1136,7 @@ static int powernowk8_target(struct cpufreq_policy *pol, 
	if (!alloc_cpumask_var(&oldmask, GFP_KERNEL))

	if (!alloc_cpumask_var(&oldmask, GFP_KERNEL))

		return -ENOMEM;

		return -ENOMEM;





	cpumask_copy(oldmask, tsk_cpumask(current));

	cpumask_copy(oldmask, tsk_cpus_allowed(current));

	set_cpus_allowed_ptr(current, cpumask_of(pol->cpu));

	set_cpus_allowed_ptr(current, cpumask_of(pol->cpu));





	if (smp_processor_id() != pol->cpu) {

	if (smp_processor_id() != pol->cpu) {

drivers/idle/i7300_idle.c

+9 −6
Original line number Original line Diff line number Diff line
@@ -81,7 +81,7 @@ static u8 i7300_idle_thrtctl_saved; 
static u8 i7300_idle_thrtlow_saved;

static u8 i7300_idle_thrtlow_saved;

static u32 i7300_idle_mc_saved;

static u32 i7300_idle_mc_saved;





static cpumask_t idle_cpumask;

static cpumask_var_t idle_cpumask;

static ktime_t start_ktime;

static ktime_t start_ktime;

static unsigned long avg_idle_us;

static unsigned long avg_idle_us;
@@ -459,9 +459,9 @@ static int i7300_idle_notifier(struct notifier_block *nb, unsigned long val, 
	spin_lock_irqsave(&i7300_idle_lock, flags);

	spin_lock_irqsave(&i7300_idle_lock, flags);

	if (val == IDLE_START) {

	if (val == IDLE_START) {





		cpu_set(smp_processor_id(), idle_cpumask);

		cpumask_set_cpu(smp_processor_id(), idle_cpumask);





		if (cpus_weight(idle_cpumask) != num_online_cpus())

		if (cpumask_weight(idle_cpumask) != num_online_cpus())

			goto end;

			goto end;





		now_ktime = ktime_get();

		now_ktime = ktime_get();
@@ -478,8 +478,8 @@ static int i7300_idle_notifier(struct notifier_block *nb, unsigned long val, 
		i7300_idle_ioat_start();

		i7300_idle_ioat_start();





	} else if (val == IDLE_END) {

	} else if (val == IDLE_END) {

		cpu_clear(smp_processor_id(), idle_cpumask);

		cpumask_clear_cpu(smp_processor_id(), idle_cpumask);

		if (cpus_weight(idle_cpumask) == (num_online_cpus() - 1)) {

		if (cpumask_weight(idle_cpumask) == (num_online_cpus() - 1)) {

			/* First CPU coming out of idle */

			/* First CPU coming out of idle */

			u64 idle_duration_us;

			u64 idle_duration_us;
@@ -553,7 +553,6 @@ struct debugfs_file_info { 
static int __init i7300_idle_init(void)

static int __init i7300_idle_init(void)

{

{

	spin_lock_init(&i7300_idle_lock);

	spin_lock_init(&i7300_idle_lock);

	cpus_clear(idle_cpumask);

	total_us = 0;

	total_us = 0;





	if (i7300_idle_platform_probe(&fbd_dev, &ioat_dev, forceload))

	if (i7300_idle_platform_probe(&fbd_dev, &ioat_dev, forceload))
@@ -565,6 +564,9 @@ static int __init i7300_idle_init(void) 
	if (i7300_idle_ioat_init())

	if (i7300_idle_ioat_init())

		return -ENODEV;

		return -ENODEV;





	if (!zalloc_cpumask_var(&idle_cpumask, GFP_KERNEL))

		return -ENOMEM;



	debugfs_dir = debugfs_create_dir("i7300_idle", NULL);

	debugfs_dir = debugfs_create_dir("i7300_idle", NULL);

	if (debugfs_dir) {

	if (debugfs_dir) {

		int i = 0;

		int i = 0;
@@ -589,6 +591,7 @@ static int __init i7300_idle_init(void) 
static void __exit i7300_idle_exit(void)

static void __exit i7300_idle_exit(void)

{

{

	idle_notifier_unregister(&i7300_idle_nb);

	idle_notifier_unregister(&i7300_idle_nb);

	free_cpumask_var(idle_cpumask);





	if (debugfs_dir) {

	if (debugfs_dir) {

		int i = 0;

		int i = 0;

drivers/scsi/fcoe/fcoe.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -1260,7 +1260,7 @@ int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, 
				"CPU.\n");

				"CPU.\n");





		spin_unlock_bh(&fps->fcoe_rx_list.lock);

		spin_unlock_bh(&fps->fcoe_rx_list.lock);

		cpu = first_cpu(cpu_online_map);

		cpu = cpumask_first(cpu_online_mask);

		fps = &per_cpu(fcoe_percpu, cpu);

		fps = &per_cpu(fcoe_percpu, cpu);

		spin_lock_bh(&fps->fcoe_rx_list.lock);

		spin_lock_bh(&fps->fcoe_rx_list.lock);

		if (!fps->thread) {

		if (!fps->thread) {

include/linux/sched.h

+1 −1
Original line number Original line Diff line number Diff line
@@ -1553,7 +1553,7 @@ struct task_struct { 
};

};





/* Future-safe accessor for struct task_struct's cpus_allowed. */

/* Future-safe accessor for struct task_struct's cpus_allowed. */

#define tsk_cpumask(tsk) (&(tsk)->cpus_allowed)

#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)





/*

/*

 * Priority of a process goes from 0..MAX_PRIO-1, valid RT

 * Priority of a process goes from 0..MAX_PRIO-1, valid RT