Commit c309b917 authored by Rusty Russell's avatar Rusty Russell
Browse files

cpumask: convert kernel/profile.c 



Impact: Reduce kernel memory usage, use new cpumask API.

Avoid a static cpumask_t for prof_cpu_mask, and an on-stack cpumask_t
in prof_cpu_mask_write_proc.  Both become cpumask_var_t.

prof_cpu_mask is only allocated when profiling is on, but the NULL
checks are optimized out by gcc for the !CPUMASK_OFFSTACK case.

Also removed some strange and unnecessary casts.

Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent bd232f97

kernel/profile.c

+25 −13
Original line number Diff line number Diff line
@@ -45,7 +45,7 @@ static unsigned long prof_len, prof_shift; 
int prof_on __read_mostly;

EXPORT_SYMBOL_GPL(prof_on);



static cpumask_t prof_cpu_mask = CPU_MASK_ALL;

static cpumask_var_t prof_cpu_mask;

#ifdef CONFIG_SMP

static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits);

static DEFINE_PER_CPU(int, cpu_profile_flip);
@@ -113,9 +113,13 @@ int __ref profile_init(void) 
	buffer_bytes = prof_len*sizeof(atomic_t);

	if (!slab_is_available()) {

		prof_buffer = alloc_bootmem(buffer_bytes);

		alloc_bootmem_cpumask_var(&prof_cpu_mask);

		return 0;

	}



	if (!alloc_cpumask_var(&prof_cpu_mask, GFP_KERNEL))

		return -ENOMEM;



	prof_buffer = kzalloc(buffer_bytes, GFP_KERNEL);

	if (prof_buffer)

		return 0;
@@ -128,6 +132,7 @@ int __ref profile_init(void) 
	if (prof_buffer)

		return 0;



	free_cpumask_var(prof_cpu_mask);

	return -ENOMEM;

}
@@ -386,13 +391,15 @@ out_free: 
		return NOTIFY_BAD;

	case CPU_ONLINE:

	case CPU_ONLINE_FROZEN:

		cpu_set(cpu, prof_cpu_mask);

		if (prof_cpu_mask != NULL)

			cpumask_set_cpu(cpu, prof_cpu_mask);

		break;

	case CPU_UP_CANCELED:

	case CPU_UP_CANCELED_FROZEN:

	case CPU_DEAD:

	case CPU_DEAD_FROZEN:

		cpu_clear(cpu, prof_cpu_mask);

		if (prof_cpu_mask != NULL)

			cpumask_clear_cpu(cpu, prof_cpu_mask);

		if (per_cpu(cpu_profile_hits, cpu)[0]) {

			page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]);

			per_cpu(cpu_profile_hits, cpu)[0] = NULL;
@@ -430,7 +437,8 @@ void profile_tick(int type) 


	if (type == CPU_PROFILING && timer_hook)

		timer_hook(regs);

	if (!user_mode(regs) && cpu_isset(smp_processor_id(), prof_cpu_mask))

	if (!user_mode(regs) && prof_cpu_mask != NULL &&

	    cpumask_test_cpu(smp_processor_id(), prof_cpu_mask))

		profile_hit(type, (void *)profile_pc(regs));

}
@@ -442,7 +450,7 @@ void profile_tick(int type) 
static int prof_cpu_mask_read_proc(char *page, char **start, off_t off,

			int count, int *eof, void *data)

{

	int len = cpumask_scnprintf(page, count, (cpumask_t *)data);

	int len = cpumask_scnprintf(page, count, data);

	if (count - len < 2)

		return -EINVAL;

	len += sprintf(page + len, "\n");
@@ -452,16 +460,20 @@ static int prof_cpu_mask_read_proc(char *page, char **start, off_t off, 
static int prof_cpu_mask_write_proc(struct file *file,

	const char __user *buffer,  unsigned long count, void *data)

{

	cpumask_t *mask = (cpumask_t *)data;

	struct cpumask *mask = data;

	unsigned long full_count = count, err;

	cpumask_t new_value;

	cpumask_var_t new_value;



	err = cpumask_parse_user(buffer, count, &new_value);

	if (err)

		return err;

	if (!alloc_cpumask_var(&new_value, GFP_KERNEL))

		return -ENOMEM;



	*mask = new_value;

	return full_count;

	err = cpumask_parse_user(buffer, count, new_value);

	if (!err) {

		cpumask_copy(mask, new_value);

		err = full_count;

	}

	free_cpumask_var(new_value);

	return err;

}



void create_prof_cpu_mask(struct proc_dir_entry *root_irq_dir)
@@ -472,7 +484,7 @@ void create_prof_cpu_mask(struct proc_dir_entry *root_irq_dir) 
	entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir);

	if (!entry)

		return;

	entry->data = (void *)&prof_cpu_mask;

	entry->data = prof_cpu_mask;

	entry->read_proc = prof_cpu_mask_read_proc;

	entry->write_proc = prof_cpu_mask_write_proc;

}

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