[PATCH 000/003] Remove getnstimestamp()

[PATCH 000/003] Remove getnstimestamp()

[Matt Helsley]

	This series removes the getnstimestamp() function from kernel/time.c in
favor of kernel/hrtimer.c's ktime_get_ts() function which currently does
exactly the same thing: retrieves a high-resolution (ns) timespec
structure and performs the wall_to_monotonic adjustment.

	As Jay Lan suggested I was going to replace calls to getnstimestamp()
with do_posix_clock_monotonic_gettime() but the hrtimer patches switched
that to a macro. ktime_get_ts() is shorter and avoids unnecessary
association with posix timers (though it does not emphasize monotonicity
or resolution).

The series:

001/003 export-ktime_get_ts.patch
	Exports ktime_get_ts()

002/003 proc-events-use-ktime-for-timestamp.patch
	Switches the only user of getnstimestamp() to ktime_get_ts()

003/003 rm-getnstimestamp.patch
	Remove getnstimestamp() from kernel/time.c


Thanks,
	-Matt Helsley

[PATCH 001/003] Export ktime_get_ts()

[Matt Helsley]

Export ktime_get_ts() to be used as a timestamp function since it
uses getnstimefoday() and does the wall_to_monotonic adjustment.

Signed-off-by: Matt Helsley <matthltc@us.ibm.com>

--

Index: linux-2.6.15-rc5-mm1/kernel/hrtimer.c
===================================================================
--- linux-2.6.15-rc5-mm1.orig/kernel/hrtimer.c
+++ linux-2.6.15-rc5-mm1/kernel/hrtimer.c
@@ -106,10 +106,11 @@ void ktime_get_ts(struct timespec *ts)
 	} while (read_seqretry(&xtime_lock, seq));
 
 	set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
 				ts->tv_nsec + tomono.tv_nsec);
 }
+EXPORT_SYMBOL_GPL(ktime_get_ts);
 
 /*
  * Functions and macros which are different for UP/SMP systems are kept in a
  * single place
  */

Re: [PATCH 002/003] Switch getnstimestamp() calls to ktime_get_ts()

[Matt Helsley]

Use ktime_get_ts() to take the timestamp instead of getnstimestamp(). This
patch prepares to remove getnstimestamp() by switching its only user to
a different function with almost exactly the same code.

Signed-off-by: Matt Helsley <matthltc@us.ibm.com>

--

Index: linux-2.6.15-rc5-mm2/drivers/connector/cn_proc.c
===================================================================
--- linux-2.6.15-rc5-mm2.orig/drivers/connector/cn_proc.c
+++ linux-2.6.15-rc5-mm2/drivers/connector/cn_proc.c
@@ -22,10 +22,11 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
 
 #include <linux/module.h>
 #include <linux/kernel.h>
+#include <linux/ktime.h>
 #include <linux/init.h>
 #include <asm/atomic.h>
 
 #include <linux/cn_proc.h>
 
@@ -54,11 +55,11 @@ void proc_fork_connector(struct task_str
 		return;
 
 	msg = (struct cn_msg*)buffer;
 	ev = (struct proc_event*)msg->data;
 	get_seq(&msg->seq, &ev->cpu);
-	getnstimestamp(&ev->timestamp);
+	ktime_get_ts(&ev->timestamp); /* get high res monotonic timestamp */
 	ev->what = PROC_EVENT_FORK;
 	ev->event_data.fork.parent_pid = task->real_parent->pid;
 	ev->event_data.fork.parent_tgid = task->real_parent->tgid;
 	ev->event_data.fork.child_pid = task->pid;
 	ev->event_data.fork.child_tgid = task->tgid;
@@ -80,11 +81,11 @@ void proc_exec_connector(struct task_str
 		return;
 
 	msg = (struct cn_msg*)buffer;
 	ev = (struct proc_event*)msg->data;
 	get_seq(&msg->seq, &ev->cpu);
-	getnstimestamp(&ev->timestamp);
+	ktime_get_ts(&ev->timestamp);
 	ev->what = PROC_EVENT_EXEC;
 	ev->event_data.exec.process_pid = task->pid;
 	ev->event_data.exec.process_tgid = task->tgid;
 
 	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
@@ -114,11 +115,11 @@ void proc_id_connector(struct task_struc
 	   	ev->event_data.id.r.rgid = task->gid;
 	   	ev->event_data.id.e.egid = task->egid;
 	} else
 	     	return;
 	get_seq(&msg->seq, &ev->cpu);
-	getnstimestamp(&ev->timestamp);
+	ktime_get_ts(&ev->timestamp);
 
 	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
 	msg->ack = 0; /* not used */
 	msg->len = sizeof(*ev);
 	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
@@ -134,11 +135,11 @@ void proc_exit_connector(struct task_str
 		return;
 
 	msg = (struct cn_msg*)buffer;
 	ev = (struct proc_event*)msg->data;
 	get_seq(&msg->seq, &ev->cpu);
-	getnstimestamp(&ev->timestamp);
+	ktime_get_ts(&ev->timestamp);
 	ev->what = PROC_EVENT_EXIT;
 	ev->event_data.exit.process_pid = task->pid;
 	ev->event_data.exit.process_tgid = task->tgid;
 	ev->event_data.exit.exit_code = task->exit_code;
 	ev->event_data.exit.exit_signal = task->exit_signal;
@@ -167,11 +168,11 @@ static void cn_proc_ack(int err, int rcv
 		return;
 
 	msg = (struct cn_msg*)buffer;
 	ev = (struct proc_event*)msg->data;
 	msg->seq = rcvd_seq;
-	getnstimestamp(&ev->timestamp);
+	ktime_get_ts(&ev->timestamp);
 	ev->cpu = -1;
 	ev->what = PROC_EVENT_NONE;
 	ev->event_data.ack.err = err;
 	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
 	msg->ack = rcvd_ack + 1;

Re: [PATCH 003/003] Remove getnstimestamp()

[Matt Helsley]

Remove getnstimestamp() in favor of ktime.h's ktime_get_ts()

Signed-off-by: Matt Helsley <matthltc@us.ibm.com>

--

Index: linux-2.6.15-rc5/kernel/time.c
===================================================================
--- linux-2.6.15-rc5.orig/kernel/time.c
+++ linux-2.6.15-rc5/kernel/time.c
@@ -562,32 +562,10 @@ void getnstimeofday(struct timespec *tv)
 	tv->tv_nsec = x.tv_usec * NSEC_PER_USEC;
 }
 EXPORT_SYMBOL_GPL(getnstimeofday);
 #endif
 
-void getnstimestamp(struct timespec *ts)
-{
-	unsigned int seq;
-	struct timespec wall2mono;
-
-	/* synchronize with settimeofday() changes */
-	do {
-		seq = read_seqbegin(&xtime_lock);
-		getnstimeofday(ts);
-		wall2mono = wall_to_monotonic;
-	} while(unlikely(read_seqretry(&xtime_lock, seq)));
-
-	/* adjust to monotonicaly-increasing values */
-	ts->tv_sec += wall2mono.tv_sec;
-	ts->tv_nsec += wall2mono.tv_nsec;
-	while (unlikely(ts->tv_nsec >= NSEC_PER_SEC)) {
-		ts->tv_nsec -= NSEC_PER_SEC;
-		ts->tv_sec++;
-	}
-}
-EXPORT_SYMBOL_GPL(getnstimestamp);
-
 /* Converts Gregorian date to seconds since 1970-01-01 00:00:00.
  * Assumes input in normal date format, i.e. 1980-12-31 23:59:59
  * => year=1980, mon=12, day=31, hour=23, min=59, sec=59.
  *
  * [For the Julian calendar (which was used in Russia before 1917,
Index: linux-2.6.15-rc5/include/linux/time.h
===================================================================
--- linux-2.6.15-rc5.orig/include/linux/time.h
+++ linux-2.6.15-rc5/include/linux/time.h
@@ -78,11 +78,10 @@ extern long do_utimes(char __user *filen
 struct itimerval;
 extern int do_setitimer(int which, struct itimerval *value,
 			struct itimerval *ovalue);
 extern int do_getitimer(int which, struct itimerval *value);
 extern void getnstimeofday(struct timespec *tv);
-extern void getnstimestamp(struct timespec *ts);
 
 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 
 /**
  * timespec_to_ns - Convert timespec to nanoseconds