1 files changed, 42 insertions, 32 deletions

diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index 6a0c62d6e44..bf2d03f8fd3 100644
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -9,7 +9,7 @@
 #include <linux/slab.h>
 #include <linux/time.h>
 #include <linux/irqnr.h>
-#include <asm/cputime.h>
+#include <linux/cputime.h>
 #include <linux/tick.h>
 
 #ifndef arch_irq_stat_cpu
@@ -18,19 +18,42 @@
 #ifndef arch_irq_stat
 #define arch_irq_stat() 0
 #endif
-#ifndef arch_idle_time
-#define arch_idle_time(cpu) 0
-#endif
+
+#ifdef arch_idle_time
+
+static cputime64_t get_idle_time(int cpu)
+{
+	cputime64_t idle;
+
+	idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
+	if (cpu_online(cpu) && !nr_iowait_cpu(cpu))
+		idle += arch_idle_time(cpu);
+	return idle;
+}
+
+static cputime64_t get_iowait_time(int cpu)
+{
+	cputime64_t iowait;
+
+	iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
+	if (cpu_online(cpu) && nr_iowait_cpu(cpu))
+		iowait += arch_idle_time(cpu);
+	return iowait;
+}
+
+#else
 
 static u64 get_idle_time(int cpu)
 {
-	u64 idle, idle_time = get_cpu_idle_time_us(cpu, NULL);
+	u64 idle, idle_time = -1ULL;
 
-	if (idle_time == -1ULL) {
-		/* !NO_HZ so we can rely on cpustat.idle */
+	if (cpu_online(cpu))
+		idle_time = get_cpu_idle_time_us(cpu, NULL);
+
+	if (idle_time == -1ULL)
+		/* !NO_HZ or cpu offline so we can rely on cpustat.idle */
 		idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
-		idle += arch_idle_time(cpu);
-	} else
+	else
 		idle = usecs_to_cputime64(idle_time);
 
 	return idle;
@@ -38,10 +61,13 @@ static u64 get_idle_time(int cpu)
 
 static u64 get_iowait_time(int cpu)
 {
-	u64 iowait, iowait_time = get_cpu_iowait_time_us(cpu, NULL);
+	u64 iowait, iowait_time = -1ULL;
+
+	if (cpu_online(cpu))
+		iowait_time = get_cpu_iowait_time_us(cpu, NULL);
 
 	if (iowait_time == -1ULL)
-		/* !NO_HZ so we can rely on cpustat.iowait */
+		/* !NO_HZ or cpu offline so we can rely on cpustat.iowait */
 		iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
 	else
 		iowait = usecs_to_cputime64(iowait_time);
@@ -49,6 +75,8 @@ static u64 get_iowait_time(int cpu)
 	return iowait;
 }
 
+#endif
+
 static int show_stat(struct seq_file *p, void *v)
 {
 	int i, j;
@@ -156,29 +184,11 @@ static int show_stat(struct seq_file *p, void *v)
 
 static int stat_open(struct inode *inode, struct file *file)
 {
-	unsigned size = 1024 + 128 * num_possible_cpus();
-	char *buf;
-	struct seq_file *m;
-	int res;
+	size_t size = 1024 + 128 * num_online_cpus();
 
 	/* minimum size to display an interrupt count : 2 bytes */
 	size += 2 * nr_irqs;
-
-	/* don't ask for more than the kmalloc() max size */
-	if (size > KMALLOC_MAX_SIZE)
-		size = KMALLOC_MAX_SIZE;
-	buf = kmalloc(size, GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
-
-	res = single_open(file, show_stat, NULL);
-	if (!res) {
-		m = file->private_data;
-		m->buf = buf;
-		m->size = ksize(buf);
-	} else
-		kfree(buf);
-	return res;
+	return single_open_size(file, show_stat, NULL, size);
 }
 
 static const struct file_operations proc_stat_operations = {
@@ -193,4 +203,4 @@ static int __init proc_stat_init(void)
 	proc_create("stat", 0, NULL, &proc_stat_operations);
 	return 0;
 }
-module_init(proc_stat_init);
+fs_initcall(proc_stat_init);