From c309b917cab55799ea489d7b5f1b77025d9f8462 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 1 Jan 2009 10:12:27 +1030 Subject: [PATCH] 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 --- kernel/profile.c | 38 +++++++++++++++++++++++++------------- 1 file changed, 25 insertions(+), 13 deletions(-) diff --git a/kernel/profile.c b/kernel/profile.c index 4cb7d68fed8..d18e2d2654f 100644 --- a/kernel/profile.c +++ b/kernel/profile.c @@ -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; } -- 2.11.4.GIT