public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: John Stultz <john.stultz@linaro.org>, Ingo Molnar <mingo@elte.hu>,
	Peter Zijlstra <peterz@infradead.org>,
	Eric Dumazet <dada1@cosmosbay.com>,
	Frederic Weisbecker <fweisbec@gmail.com>
Subject: [RFC patch 6/8] timekeeping: Delay update of clock->cycle_last
Date: Thu, 21 Feb 2013 22:51:39 -0000	[thread overview]
Message-ID: <20130221224231.105416300@linutronix.de> (raw)
In-Reply-To: 20130221220147.719832397@linutronix.de

[-- Attachment #1: timekeeping-delay-clock-cycle-last-update.patch --]
[-- Type: text/plain, Size: 1017 bytes --]

For calculating the new timekeeper values store the new cycle_last
value in the timekeeper and update the clock->cycle_last just when we
actually update the new values.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/time/timekeeping.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Index: linux-2.6/kernel/time/timekeeping.c
===================================================================
--- linux-2.6.orig/kernel/time/timekeeping.c
+++ linux-2.6/kernel/time/timekeeping.c
@@ -1120,7 +1120,7 @@ static cycle_t logarithmic_accumulation(
 
 	/* Accumulate one shifted interval */
 	offset -= interval;
-	tk->clock->cycle_last += interval;
+	tk->cycle_last += interval;
 
 	tk->xtime_nsec += tk->xtime_interval << shift;
 	accumulate_nsecs_to_secs(tk);
@@ -1235,6 +1235,8 @@ static void update_wall_time(void)
 	 */
 	accumulate_nsecs_to_secs(tk);
 
+	/* Update clock->cycle_last with the new value */
+	clock->cycle_last = tk->cycle_last;
 	timekeeping_update(tk, false);
 
 out:



  parent reply	other threads:[~2013-02-21 22:52 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-21 22:51 [RFC patch 0/8] timekeeping: Implement shadow timekeeper to shorten in kernel reader side blocking Thomas Gleixner
2013-02-21 22:51 ` [RFC patch 2/8] timekeeping: Make jiffies_lock internal Thomas Gleixner
2013-02-21 22:51 ` [RFC patch 1/8] timekeeping: Calc stuff once Thomas Gleixner
2013-02-21 22:51 ` [RFC patch 3/8] timekeeping: Move lock out of timekeeper struct Thomas Gleixner
2013-02-21 22:51 ` [RFC patch 4/8] timekeeping: Split timekeeper_lock into lock and seqcount Thomas Gleixner
2013-02-21 22:51 ` [RFC patch 5/8] timekeeping: Store cycle_last value in timekeeper struct as well Thomas Gleixner
2013-02-21 22:51 ` Thomas Gleixner [this message]
2013-02-21 22:51 ` [RFC patch 7/8] timekeeping: Implement a shadow timekeeper Thomas Gleixner
2013-02-22 23:53   ` John Stultz
2013-02-26 12:17     ` Thomas Gleixner
2013-02-21 22:51 ` [RFC patch 8/8] timekeeping: Shorten seq_count region Thomas Gleixner
2013-02-21 23:06 ` [RFC patch 0/8] timekeeping: Implement shadow timekeeper to shorten in kernel reader side blocking Eric Dumazet

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=20130221224231.105416300@linutronix.de \
    --to=tglx@linutronix.de \
    --cc=dada1@cosmosbay.com \
    --cc=fweisbec@gmail.com \
    --cc=john.stultz@linaro.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=peterz@infradead.org \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox