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convert sys_nanosleep() to use new soft-timer subsystem

From:  Nishanth Aravamudan <nacc@us.ibm.com>
To:  john stultz <johnstul@us.ibm.com>
Subject:  [RFC][PATCH 3/4] convert sys_nanosleep() to use new soft-timer subsystem
Date:  Tue, 17 May 2005 16:37:39 -0700
Cc:  lkml <linux-kernel@vger.kernel.org>, Tim Schmielau <tim@physik3.uni-rostock.de>, George Anzinger <george@mvista.com>, albert@users.sourceforge.net, Ulrich Windl <ulrich.windl@rz.uni-regensburg.de>, Christoph Lameter <clameter@sgi.com>, Dominik Brodowski <linux@dominikbrodowski.de>, David Mosberger <davidm@hpl.hp.com>, Andi Kleen <ak@suse.de>, paulus@samba.org, schwidefsky@de.ibm.com, keith maanthey <kmannth@us.ibm.com>, Chris McDermott <lcm@us.ibm.com>, Max Asbock <masbock@us.ibm.com>, mahuja@us.ibm.com, Darren Hart <darren@dvhart.com>, "Darrick J. Wong" <djwong@us.ibm.com>, Anton Blanchard <anton@samba.org>, donf@us.ibm.com, mpm@selenic.com, benh@kernel.crashing.org

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;
 	}
-
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