kernel_optimize_test/fs/proc/uptime.c
Alexey Dobriyan 6c87df37dc proc: revert /proc/uptime to ->read_proc hook
Turned out some VMware userspace does pread(2) on /proc/uptime, but
seqfiles currently don't allow pread() resulting in -ESPIPE.

Seqfiles in theory can do pread(), but this can be a long story,
so revert to ->read_proc until then.

http://bugzilla.kernel.org/show_bug.cgi?id=11856

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2008-10-27 22:56:56 +03:00

46 lines
1.1 KiB
C

#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <asm/cputime.h>
static int proc_calc_metrics(char *page, char **start, off_t off,
int count, int *eof, int len)
{
if (len <= off + count)
*eof = 1;
*start = page + off;
len -= off;
if (len > count)
len = count;
if (len < 0)
len = 0;
return len;
}
static int uptime_read_proc(char *page, char **start, off_t off, int count,
int *eof, void *data)
{
struct timespec uptime;
struct timespec idle;
int len;
cputime_t idletime = cputime_add(init_task.utime, init_task.stime);
do_posix_clock_monotonic_gettime(&uptime);
monotonic_to_bootbased(&uptime);
cputime_to_timespec(idletime, &idle);
len = sprintf(page, "%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 proc_calc_metrics(page, start, off, count, eof, len);
}
static int __init proc_uptime_init(void)
{
create_proc_read_entry("uptime", 0, NULL, uptime_read_proc, NULL);
return 0;
}
module_init(proc_uptime_init);