[RFC][PATCH 3/4] convert sys_nanosleep() to use new soft-timer subsystem

Nishanth Aravamudan
2005-05-17T23:43:28Z

On 17.05.2005 [16:33:00 -0700], Nishanth Aravamudan wrote:
> On 13.05.2005 [17:16:35 -0700], john stultz wrote:
> > All,
> > This patch implements the architecture independent portion of the new
> > time of day subsystem. For a brief description on the rework, see here:
> > http://lwn.net/Articles/120850/ (Many thanks to the LWN team for that
> > easy to understand writeup!)
> >
> > I intend this to be the last RFC release and to submit this patch to
> > Andrew for for testing near the end of this month. So please, if you
> > have any complaints, suggestions, or blocking issues, let me know.
>
> I have been working closely with John to re-work the soft-timer subsytem
> to use the new timeofday() subsystem. The following patches attempts to
> begin this process. I would greatly appreciate any comments.

Description: Convert sys_nanosleep() to use the new timerinterval-based
soft-timer interfaces.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>

diff -urpN 2.6.12-rc4-tod-timer-a/kernel/timer.c 2.6.12-rc4-tod-timer-b/kernel/timer.c
--- 2.6.12-rc4-tod-timer-a/kernel/timer.c 2005-05-17 16:09:40.000000000 -0700
+++ 2.6.12-rc4-tod-timer-b/kernel/timer.c 2005-05-17 16:11:47.000000000 -0700
@@ -1460,21 +1460,21 @@ asmlinkage long sys_gettid(void)

static long __sched nanosleep_restart(struct restart_block *restart)
{
- unsigned long expire = restart->arg0, now = jiffies;
+ nsec_t expire = restart->arg0, now = do_monotonic_clock();
struct timespec __user *rmtp = (struct timespec __user *) restart->arg1;
long ret;

/* Did it expire while we handled signals? */
- if (!time_after(expire, now))
+ if (now > expire)
return 0;

- current->state = TASK_INTERRUPTIBLE;
- expire = schedule_timeout(expire - now);
+ set_current_state(TASK_INTERRUPTIBLE);
+ expire = schedule_timeout_nsecs(expire - now);

ret = 0;
if (expire) {
struct timespec t;
- jiffies_to_timespec(expire, &t);
+ t = ns_to_timespec(expire);

ret = -ERESTART_RESTARTBLOCK;
if (rmtp && copy_to_user(rmtp, &t, sizeof(t)))
@@ -1487,7 +1487,7 @@ static long __sched nanosleep_restart(st
asmlinkage long sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp)
{
struct timespec t;
- unsigned long expire;
+ nsec_t expire;
long ret;

if (copy_from_user(&t, rqtp, sizeof(t)))
@@ -1496,20 +1496,20 @@ asmlinkage long sys_nanosleep(struct tim
if ((t.tv_nsec >= 1000000000L) || (t.tv_nsec < 0) || (t.tv_sec < 0))
return -EINVAL;

- expire = timespec_to_jiffies(&t) + (t.tv_sec || t.tv_nsec);
- current->state = TASK_INTERRUPTIBLE;
- expire = schedule_timeout(expire);
+ expire = timespec_to_ns(&t);
+ set_current_state(TASK_INTERRUPTIBLE);
+ expire = schedule_timeout_nsecs(expire);

ret = 0;
if (expire) {
struct restart_block *restart;
- jiffies_to_timespec(expire, &t);
+ t = ns_to_timespec(expire);
if (rmtp && copy_to_user(rmtp, &t, sizeof(t)))
return -EFAULT;

restart = &current_thread_info()->restart_block;
restart->fn = nanosleep_restart;
- restart->arg0 = jiffies + expire;
+ restart->arg0 = do_monotonic_clock() + expire;
restart->arg1 = (unsigned long) rmtp;
ret = -ERESTART_RESTARTBLOCK;
}