LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Thomas Gleixner <tglx@linutronix.de>
To: Andrew Morton <akpm@osdl.org>
Cc: LKML <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@elte.hu>,
	John Stultz <johnstul@us.ibm.com>,
	Arjan van de Veen <arjan@infradead.org>,
	Roman Zippel <zippel@linux-m68k.org>
Subject: [patch 03/46] [RFC] HZ free ntp
Date: Tue, 23 Jan 2007 22:00:58 -0000	[thread overview]
Message-ID: <20070123211203.020952000@localhost.localdomain> (raw)
In-Reply-To: <20070123211159.178138000@localhost.localdomain>

[-- Attachment #1: ntp-make-dyntick-aware.patch --]
[-- Type: text/plain, Size: 5526 bytes --]

>From johnstul@us.ibm.com Wed Dec 20 02:36:15 2006

Distangle the NTP update from HZ. This is necessary for dynamic tick
enabled kernels.

---
 include/linux/timex.h |    7 +++++++
 kernel/hrtimer.c      |   11 ++++++++---
 kernel/time/ntp.c     |   30 +++++++++++++++++++-----------
 kernel/timer.c        |    4 ++--
 4 files changed, 36 insertions(+), 16 deletions(-)

Index: linux-2.6.20-rc4-mm1-bo/include/linux/timex.h
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/include/linux/timex.h
+++ linux-2.6.20-rc4-mm1-bo/include/linux/timex.h
@@ -286,6 +286,13 @@ static inline void time_interpolator_upd
 
 #define TICK_LENGTH_SHIFT	32
 
+#ifdef CONFIG_NO_HZ
+#define NTP_INTERVAL_FREQ  (2)
+#else
+#define NTP_INTERVAL_FREQ  (HZ)
+#endif
+#define NTP_INTERVAL_LENGTH (NSEC_PER_SEC/NTP_INTERVAL_FREQ)
+
 /* Returns how long ticks are at present, in ns / 2^(SHIFT_SCALE-10). */
 extern u64 current_tick_length(void);
 
Index: linux-2.6.20-rc4-mm1-bo/kernel/time/ntp.c
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/kernel/time/ntp.c
+++ linux-2.6.20-rc4-mm1-bo/kernel/time/ntp.c
@@ -24,7 +24,7 @@ static u64 tick_length, tick_length_base
 
 #define MAX_TICKADJ		500		/* microsecs */
 #define MAX_TICKADJ_SCALED	(((u64)(MAX_TICKADJ * NSEC_PER_USEC) << \
-				  TICK_LENGTH_SHIFT) / HZ)
+				  TICK_LENGTH_SHIFT) / NTP_INTERVAL_FREQ)
 
 /*
  * phase-lock loop variables
@@ -46,13 +46,17 @@ long time_adjust;
 
 static void ntp_update_frequency(void)
 {
-	tick_length_base = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ) << TICK_LENGTH_SHIFT;
-	tick_length_base += (s64)CLOCK_TICK_ADJUST << TICK_LENGTH_SHIFT;
-	tick_length_base += (s64)time_freq << (TICK_LENGTH_SHIFT - SHIFT_NSEC);
+	u64 second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
+				<< TICK_LENGTH_SHIFT;
+	second_length += (s64)CLOCK_TICK_ADJUST << TICK_LENGTH_SHIFT;
+	second_length += (s64)time_freq << (TICK_LENGTH_SHIFT - SHIFT_NSEC);
 
-	do_div(tick_length_base, HZ);
+	tick_length_base = second_length;
 
-	tick_nsec = tick_length_base >> TICK_LENGTH_SHIFT;
+	do_div(second_length, HZ);
+	tick_nsec = second_length >> TICK_LENGTH_SHIFT;
+
+	do_div(tick_length_base, NTP_INTERVAL_FREQ);
 }
 
 /**
@@ -162,7 +166,7 @@ void second_overflow(void)
 			tick_length -= MAX_TICKADJ_SCALED;
 		} else {
 			tick_length += (s64)(time_adjust * NSEC_PER_USEC /
-					     HZ) << TICK_LENGTH_SHIFT;
+					NTP_INTERVAL_FREQ) << TICK_LENGTH_SHIFT;
 			time_adjust = 0;
 		}
 	}
@@ -239,7 +243,8 @@ int do_adjtimex(struct timex *txc)
 		    result = -EINVAL;
 		    goto leave;
 		}
-		time_freq = ((s64)txc->freq * NSEC_PER_USEC) >> (SHIFT_USEC - SHIFT_NSEC);
+		time_freq = ((s64)txc->freq * NSEC_PER_USEC)
+				>> (SHIFT_USEC - SHIFT_NSEC);
 	    }
 
 	    if (txc->modes & ADJ_MAXERROR) {
@@ -309,7 +314,8 @@ int do_adjtimex(struct timex *txc)
 		    freq_adj += time_freq;
 		    freq_adj = min(freq_adj, (s64)MAXFREQ_NSEC);
 		    time_freq = max(freq_adj, (s64)-MAXFREQ_NSEC);
-		    time_offset = (time_offset / HZ) << SHIFT_UPDATE;
+		    time_offset = (time_offset / NTP_INTERVAL_FREQ)
+		    			<< SHIFT_UPDATE;
 		} /* STA_PLL */
 	    } /* txc->modes & ADJ_OFFSET */
 	    if (txc->modes & ADJ_TICK)
@@ -324,8 +330,10 @@ leave:	if ((time_status & (STA_UNSYNC|ST
 	if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
 	    txc->offset	   = save_adjust;
 	else
-	    txc->offset    = shift_right(time_offset, SHIFT_UPDATE) * HZ / 1000;
-	txc->freq	   = (time_freq / NSEC_PER_USEC) << (SHIFT_USEC - SHIFT_NSEC);
+	    txc->offset    = shift_right(time_offset, SHIFT_UPDATE)
+	    			* NTP_INTERVAL_FREQ / 1000;
+	txc->freq	   = (time_freq / NSEC_PER_USEC)
+				<< (SHIFT_USEC - SHIFT_NSEC);
 	txc->maxerror	   = time_maxerror;
 	txc->esterror	   = time_esterror;
 	txc->status	   = time_status;
Index: linux-2.6.20-rc4-mm1-bo/kernel/timer.c
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/kernel/timer.c
+++ linux-2.6.20-rc4-mm1-bo/kernel/timer.c
@@ -890,7 +890,7 @@ void __init timekeeping_init(void)
 	ntp_clear();
 
 	clock = clocksource_get_next();
-	clocksource_calculate_interval(clock, tick_nsec);
+	clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
 	clock->cycle_last = clocksource_read(clock);
 
 	write_sequnlock_irqrestore(&xtime_lock, flags);
@@ -1092,7 +1092,7 @@ static void update_wall_time(void)
 	if (change_clocksource()) {
 		clock->error = 0;
 		clock->xtime_nsec = 0;
-		clocksource_calculate_interval(clock, tick_nsec);
+		clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
 	}
 }
 
Index: linux-2.6.20-rc4-mm1-bo/kernel/hrtimer.c
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/kernel/hrtimer.c
+++ linux-2.6.20-rc4-mm1-bo/kernel/hrtimer.c
@@ -128,15 +128,20 @@ EXPORT_SYMBOL_GPL(ktime_get_ts);
 static void hrtimer_get_softirq_time(struct hrtimer_base *base)
 {
 	ktime_t xtim, tomono;
+	struct timespec xts;
 	unsigned long seq;
 
 	do {
 		seq = read_seqbegin(&xtime_lock);
-		xtim = timespec_to_ktime(xtime);
-		tomono = timespec_to_ktime(wall_to_monotonic);
-
+#ifdef CONFIG_NO_HZ
+		getnstimeofday(&xts);
+#else
+		xts = xtime;
+#endif
 	} while (read_seqretry(&xtime_lock, seq));
 
+	xtim = timespec_to_ktime(xts);
+	tomono = timespec_to_ktime(wall_to_monotonic);
 	base[CLOCK_REALTIME].softirq_time = xtim;
 	base[CLOCK_MONOTONIC].softirq_time = ktime_add(xtim, tomono);
 }

--


  parent reply	other threads:[~2007-01-23 22:17 UTC|newest]

Thread overview: 78+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-23 22:00 [patch 00/46] High resolution timer / dynamic tick update Thomas Gleixner
2007-01-23 22:00 ` [patch 01/46] Add irq flag to disable balancing for an interrupt Thomas Gleixner
2007-01-23 22:00 ` [patch 02/46] Add a functions to handle interrupt affinity setting Thomas Gleixner
2007-01-23 22:00 ` Thomas Gleixner [this message]
2007-01-23 22:00 ` [patch 04/46] Uninline jiffies.h functions Thomas Gleixner
2007-01-23 22:01 ` [patch 05/46] Thomas Gleixner
2007-01-23 22:01 ` [patch 06/46] Fix timeout overflow with jiffies Thomas Gleixner
2007-01-23 22:01 ` [patch 07/46] GTOD: persistent clock support Thomas Gleixner
2007-01-23 22:01 ` [patch 08/46] i386: use GTOD " Thomas Gleixner
2007-01-23 22:01 ` [patch 09/46] i386 Remove useless code in tsc.c Thomas Gleixner
2007-01-23 22:01 ` [patch 10/46] Simplify the registration of clocksources Thomas Gleixner
2007-01-23 22:01 ` [patch 11/46] x86: rewrite SMP TSC sync code Thomas Gleixner
2007-01-23 22:01 ` [patch 12/46] clocksource: replace is_continuous by a flag field Thomas Gleixner
2007-01-24 11:23   ` [patch] clocksource: fixup is_continous changes in vmitime.c Ingo Molnar
2007-01-24 11:53     ` Thomas Gleixner
2007-01-23 22:01 ` [patch 13/46] clocksource: fixup is_continous changes on ARM Thomas Gleixner
2007-01-23 22:01 ` [patch 14/46] clocksource: fixup is_continous changes on AVR32 Thomas Gleixner
2007-01-23 22:01 ` [patch 15/46] clocksource: fixup is_continous changes on S390 Thomas Gleixner
2007-01-23 22:01 ` [patch 16/46] clocksource: fixup is_continous changes on MIPS Thomas Gleixner
2007-01-23 22:01 ` [patch 17/46] clocksource: Remove the update callback Thomas Gleixner
2007-01-23 22:01 ` [patch 18/46] clocksource: Add verification (watchdog) helper Thomas Gleixner
2007-01-24 15:42   ` [patch] clocksource: add verification (watchdog) helper, fix Ingo Molnar
2007-01-23 22:01 ` [patch 19/46] Mark TSC on GeodeLX reliable Thomas Gleixner
2007-01-23 22:01 ` [patch 20/46] uninline irq_enter() Thomas Gleixner
2007-01-23 22:01 ` [patch 21/46] Fix cascade lookup of next_timer_interrupt Thomas Gleixner
2007-01-23 22:01 ` [patch 22/46] Extend next_timer_interrupt() to use a reference jiffie Thomas Gleixner
2007-01-23 22:01 ` [patch 23/46] hrtimers: namespace and enum cleanup Thomas Gleixner
2007-01-23 22:01 ` [patch 24/46] hrtimers: namespace and enum cleanup vs. git-input Thomas Gleixner
2007-01-23 22:01 ` [patch 25/46] hrtimers: cleanup locking Thomas Gleixner
2007-01-23 22:01 ` [patch 26/46] hrtimers; add state tracking Thomas Gleixner
2007-01-23 22:01 ` [patch 27/46] hrtimers: clean up callback tracking Thomas Gleixner
2007-01-23 22:01 ` [patch 28/46] hrtimers: move and add documentation Thomas Gleixner
2007-01-23 22:01 ` [patch 29/46] ACPI: fix missing include for UP Thomas Gleixner
2007-01-23 22:01 ` [patch 30/46] ACPI keep track of timer broadcasting Thomas Gleixner
2007-01-23 22:01 ` [patch 31/46] Allow early access to the power management timer Thomas Gleixner
2007-01-23 22:01 ` [patch 32/46] i386, apic: clean up the APIC code Thomas Gleixner
2007-01-23 22:01 ` [patch 33/46] clockevents: add core functionality Thomas Gleixner
2007-01-23 22:01 ` [patch 34/46] tick-management: " Thomas Gleixner
2007-01-23 22:01 ` [patch 35/46] tick-management: broadcast functionality Thomas Gleixner
2007-01-23 22:01 ` [patch 36/46] tick-management: dyntick / highres functionality Thomas Gleixner
2007-01-28  2:03   ` [PATCH] high_res_timers: precisely update_process_times; " Karsten Wiese
2007-01-23 22:01 ` [patch 37/46] clockevents: i383 drivers Thomas Gleixner
2007-01-23 22:01 ` [patch 38/46] i386 rework local apic timer calibration Thomas Gleixner
2007-01-23 22:01 ` [patch 39/46] i386 prepare for dyntick Thomas Gleixner
2007-01-23 22:01 ` [patch 40/46] i386 prepare nmi watchdog for dynticks Thomas Gleixner
2007-01-23 22:01 ` [patch 41/46] i386: enable dynticks in kconfig Thomas Gleixner
2007-01-23 22:01 ` [patch 42/46] hrtimers: add high resolution timer support Thomas Gleixner
2007-01-23 22:01 ` [patch 43/46] hrtimers: prevent possible itimer DoS Thomas Gleixner
2007-01-23 22:01 ` [patch 44/46] Add debugging feature /proc/timer_stat Thomas Gleixner
2007-01-23 22:01 ` [patch 45/46] Add debugging feature /proc/timer_list Thomas Gleixner
2007-01-23 22:01 ` [patch 46/46] Add SysRq-Q to print timer_list debug info Thomas Gleixner
2007-01-24  2:16 ` [patch 00/46] High resolution timer / dynamic tick update Daniel Walker
2007-01-24  2:23   ` Andrew Morton
2007-01-24  3:25     ` Daniel Walker
2007-01-24  7:07   ` Ingo Molnar
2007-01-24  9:30     ` Daniel Walker
2007-01-24  9:51       ` Ingo Molnar
2007-01-24 10:23         ` Daniel Walker
2007-01-24 10:29           ` Ingo Molnar
2007-01-24 10:53             ` Daniel Walker
2007-01-24 11:04               ` Ingo Molnar
2007-01-24 11:13           ` Thomas Gleixner
2007-01-24 15:53             ` Daniel Walker
     [not found]               ` <20070124160046.GA24798@elte.hu>
2007-01-24 17:21                 ` Daniel Walker
     [not found]                 ` <1169655076.19471.241.camel@imap.mvista.com>
2007-01-24 19:38                   ` Ingo Molnar
2007-01-24 20:09                     ` Daniel Walker
2007-01-24 20:13                       ` Ingo Molnar
2007-01-24 19:57       ` john stultz
2007-01-24 20:51         ` Daniel Walker
2007-01-24 21:23           ` john stultz
2007-01-24 21:37             ` Daniel Walker
2007-01-25  6:10           ` Ingo Molnar
2007-01-25  6:37           ` Ingo Molnar
2007-01-25  6:32         ` Ingo Molnar
2007-01-25 16:38           ` Daniel Walker
2007-01-28  2:17 ` Andrew Morton
2007-01-29 21:31   ` john stultz
2007-01-29 21:45     ` john stultz

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20070123211203.020952000@localhost.localdomain \
    --to=tglx@linutronix.de \
    --cc=akpm@osdl.org \
    --cc=arjan@infradead.org \
    --cc=johnstul@us.ibm.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=zippel@linux-m68k.org \
    --subject='Re: [patch 03/46] [RFC] HZ free ntp' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).