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: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/kernel/profile.c b/kernel/profile.c
index 4cb7d68..d18e2d2 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -45,7 +45,7 @@
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 @@
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 @@
if (prof_buffer)
return 0;
+ free_cpumask_var(prof_cpu_mask);
return -ENOMEM;
}
@@ -386,13 +391,15 @@
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 @@
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 @@
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_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 @@
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;
}