summaryrefslogtreecommitdiff
path: root/fs/proc/uptime.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/proc/uptime.c')
-rw-r--r--fs/proc/uptime.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/fs/proc/uptime.c b/fs/proc/uptime.c
new file mode 100644
index 000000000..33de567c2
--- /dev/null
+++ b/fs/proc/uptime.c
@@ -0,0 +1,52 @@
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/time.h>
+#include <linux/kernel_stat.h>
+#include <linux/cputime.h>
+
+static int uptime_proc_show(struct seq_file *m, void *v)
+{
+ struct timespec uptime;
+ struct timespec idle;
+ u64 idletime;
+ u64 nsec;
+ u32 rem;
+ int i;
+
+ idletime = 0;
+ for_each_possible_cpu(i)
+ idletime += (__force u64) kcpustat_cpu(i).cpustat[CPUTIME_IDLE];
+
+ get_monotonic_boottime(&uptime);
+ nsec = cputime64_to_jiffies64(idletime) * TICK_NSEC;
+ idle.tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem);
+ idle.tv_nsec = rem;
+ seq_printf(m, "%lu.%02lu %lu.%02lu\n",
+ (unsigned long) uptime.tv_sec,
+ (uptime.tv_nsec / (NSEC_PER_SEC / 100)),
+ (unsigned long) idle.tv_sec,
+ (idle.tv_nsec / (NSEC_PER_SEC / 100)));
+ return 0;
+}
+
+static int uptime_proc_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, uptime_proc_show, NULL);
+}
+
+static const struct file_operations uptime_proc_fops = {
+ .open = uptime_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int __init proc_uptime_init(void)
+{
+ proc_create("uptime", 0, NULL, &uptime_proc_fops);
+ return 0;
+}
+fs_initcall(proc_uptime_init);