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From: john stultz <johnstul@us.ibm.com>
To: lkml <linux-kernel@vger.kernel.org>
Cc: George Anzinger <george@mvista.com>,
	frank@tuxrocks.com, Anton Blanchard <anton@samba.org>,
	benh@kernel.crashing.org, Nishanth Aravamudan <nacc@us.ibm.com>,
	Roman Zippel <zippel@linux-m68k.org>,
	Ulrich Windl <ulrich.windl@rz.uni-regensburg.de>
Subject: [RFC][PATCH - 12/13] NTP cleanup: cleanup ntp_advance() adjtime code
Date: Wed, 10 Aug 2005 18:36:20 -0700	[thread overview]
Message-ID: <1123724180.32531.6.camel@cog.beaverton.ibm.com> (raw)
In-Reply-To: <1123724120.32531.5.camel@cog.beaverton.ibm.com>

All,
	This patch simplifies and cleans up the adjtime code in ntp_advance and
corrects a comment.

Any comments or feedback would be greatly appreciated.

thanks
-john

linux-2.6.13-rc6_timeofday-ntp-part12_B5.patch
============================================
diff --git a/kernel/ntp.c b/kernel/ntp.c
--- a/kernel/ntp.c
+++ b/kernel/ntp.c
@@ -156,29 +156,25 @@ void ntp_advance(unsigned long interval_
 	shifted_ppm_sum += ss_adj << SHIFT_USEC;
 
 
-	if ( (time_adjust_step = ntp_adjtime_offset) != 0 ) {
-	    /* We are doing an adjtime thing.
-	     *
-	     * Prepare time_adjust_step to be within bounds.
-	     * Note that a positive ntp_adjtime_offset means we want the clock
-	     * to run faster.
-	     *
-	     * Limit the amount of the step to be in the range
-	     * -tickadj .. +tickadj
-	     */
-		if (ntp_adjtime_offset > tickadj)
-			time_adjust_step = tickadj;
-		else if (ntp_adjtime_offset < -tickadj)
-			time_adjust_step = -tickadj;
+	/* Calculate the fixed tick adjustment */
+	fixed_tick_ns_adj = 0;
 
-	    /* Reduce by this step the amount of time left  */
-	    ntp_adjtime_offset -= time_adjust_step;
+	/* If we are doing an adjtime thing */
+	if (ntp_adjtime_offset) {
+		long adjust_step = ntp_adjtime_offset;
+		/* Limit the amount of the step to be in the range
+		 * -tickadj .. +tickadj
+		 */
+		adjust_step = min_t(long, tickadj, adjust_step);
+		adjust_step = max_t(long, -tickadj, adjust_step);
+		/* Reduce by this step the amount of time left  */
+		ntp_adjtime_offset -= adjust_step;
+		fixed_tick_ns_adj += adjust_step * 1000;
 	}
-	fixed_tick_ns_adj = time_adjust_step * 1000;
 
 	/*
-	 * Advance the phase, once it gets to one microsecond, then
-	 * advance the tick more.
+	 * Advance the phase, once it gets to one nanosecond,
+	 * then advance the fixed_tick_ns_adj.
 	 */
 	time_phase += time_adj;
 	if (time_phase <= -FINENSEC) {



  reply	other threads:[~2005-08-11  1:36 UTC|newest]

Thread overview: 71+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-08-11  1:21 [RFC - 0/13] NTP cleanup work (v. B5) john stultz
2005-08-11  1:23 ` [RFC][PATCH - 1/13] NTP cleanup: Move NTP code into ntp.c john stultz
2005-08-11  1:25   ` [RFC][PATCH - 2/13] NTP cleanup: Move arches to new ntp interfaces john stultz
2005-08-11  1:26     ` [RFC][PATCH - 3/13] NTP cleanup: Remove unused NTP PPS code john stultz
2005-08-11  1:27       ` [RFC][PATCH - 4/13] NTP cleanup: Breakup ntp_adjtimex() john stultz
2005-08-11  1:28         ` [RFC][PATCH - 5/13] NTP cleanup: Break out leapsecond processing john stultz
2005-08-11  1:28           ` [RFC][PATCH - 6/13] NTP cleanup: Clean up ntp_adjtimex() arguement checking john stultz
2005-08-11  1:31             ` [RFC][PATCH - 7/13] NTP cleanup: Cleanup signed shifting logic john stultz
2005-08-11  1:31               ` [RFC][PATCH - 8/13] NTP cleanup: Integrate second_overflow() logic john stultz
2005-08-11  1:33                 ` [RFC][PATCH - 9/13] NTP cleanup: Improve NTP variable names john stultz
2005-08-11  1:33                   ` [RFC][PATCH - 10/13] NTP cleanup: Use ntp_lock instead of xtime_lock john stultz
2005-08-11  1:35                     ` [RFC][PATCH - 11/13] NTP cleanup: Introduce PPM adjustment variables john stultz
2005-08-11  1:36                       ` john stultz [this message]
2005-08-11  1:38                         ` [RFC][PATCH - 13/13] NTP cleanup: drop time_phase and time_adj add copyright john stultz
2005-08-16  2:08         ` [RFC][PATCH - 4/13] NTP cleanup: Breakup ntp_adjtimex() john stultz
2005-08-11  2:13 ` [RFC - 0/9] Generic timekeeping subsystem (v. B5) john stultz
2005-08-11  2:14   ` [PATCH 1/9] Timesource management code john stultz
2005-08-11  2:16     ` [PATCH 2/9] Generic timekeeping core subsystem john stultz
2005-08-11  2:18       ` [PATCH 3/9] Generic timekeeping i386 arch specific changes, part 1 john stultz
2005-08-11  2:19         ` [PATCH 4/9] generic timekeeping i386 arch specific changes, part 2 john stultz
2005-08-11  2:20           ` [PATCH 5/9] generic timekeeping i386 arch specific changes, part 3 john stultz
2005-08-11  2:21             ` [PATCH 6/9] generic timekeeping i386 arch specific changes, part 4 john stultz
2005-08-11  2:23               ` [PATCH 7/9] generic timekeeping i386 arch specific changes, part 5 john stultz
2005-08-11  2:24                 ` [PATCH 8/9] generic timekeeping i386 arch specific changes, part 6 john stultz
2005-08-11  2:25                   ` [PATCH 9/9] generic timekeeping i386 specific timesources john stultz
2005-08-11  2:32   ` [RFC - 0/9] Generic timekeeping subsystem (v. B5) Lee Revell
2005-08-11  2:39     ` john stultz
2005-08-11  2:44       ` Lee Revell
2005-08-11  6:17     ` Ulrich Windl
2005-08-11  2:37   ` [RFC] Cumulative NTP cleanujp and generic timekeeping patch (v B5) john stultz
2005-08-15 22:14   ` [RFC - 0/9] Generic timekeeping subsystem (v. B5) Roman Zippel
2005-08-16  0:10     ` john stultz
2005-08-16 18:25       ` Christoph Lameter
2005-08-16 23:48         ` john stultz
2005-08-17  0:14           ` Christoph Lameter
2005-08-17  0:17             ` john stultz
2005-08-17  0:21               ` Christoph Lameter
2005-08-17  6:08         ` Ulrich Windl
2005-08-17 14:07           ` Christoph Lameter
2005-08-17  0:28       ` Roman Zippel
2005-08-17  1:17         ` john stultz
2005-08-17  7:40           ` Ulrich Windl
2005-08-19  0:27           ` Roman Zippel
2005-08-20  2:32             ` john stultz
2005-08-21 23:19               ` Roman Zippel
2005-08-22 18:57                 ` john stultz
2005-08-23 11:30                   ` Roman Zippel
2005-08-23 18:52                     ` john stultz
2005-08-23 20:51                     ` john stultz
2005-08-23 21:34                       ` Roman Zippel
2005-08-23 23:14                         ` john stultz
2005-08-23 23:54                           ` Roman Zippel
2005-08-24  0:29                             ` George Anzinger
2005-08-24 20:36                               ` john stultz
2005-08-24 23:46                                 ` George Anzinger
2005-08-25  0:42                                   ` john stultz
2005-08-25  1:44                                     ` George Anzinger
2005-08-25  2:13                                       ` john stultz
2005-08-24  6:34                             ` Ulrich Windl
2005-08-24  9:47                               ` Roman Zippel
2005-08-24 18:00                             ` john stultz
2005-08-24 18:48                               ` Roman Zippel
2005-08-24 19:15                                 ` john stultz
2005-08-24 19:49                                   ` Roman Zippel
2005-08-24 22:40                                     ` john stultz
2005-08-25  0:45                                       ` Roman Zippel
2005-08-25 18:08                                         ` john stultz
2005-08-17 19:03         ` George Anzinger
2005-08-15 22:12 ` [RFC - 0/13] NTP cleanup work " Roman Zippel
2005-08-15 22:46   ` john stultz
2005-08-17  0:10     ` Roman Zippel

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