public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: question about periodic clocks
Date: Fri, 09 Mar 2007 15:26:40 -0800	[thread overview]
Message-ID: <45F1ED30.5070402@goop.org> (raw)

How does the clock period get set on periodic timers?  In my clock
driver, I'm seeing a call to ->set_mode(CLOCK_EVT_MODE_PERIODIC, evt),
but then... nothing.  I was expecting a call to set_next_event to set
the timer period.

The calltrace is:

#0  xen_new_set_mode (mode=CLOCK_EVT_MODE_PERIODIC, evt=0xc10a2ac0)
    at arch/i386/xen/time.c:275
#1  0xc01323da in clockevents_set_mode (dev=0xc10a2ac0, 
    mode=CLOCK_EVT_MODE_PERIODIC) at kernel/time/clockevents.c:64
#2  0xc0132854 in tick_setup_periodic (dev=0xc10a2ac0, 
    broadcast=<value optimized out>) at kernel/time/tick-common.c:111

and tick_setup_periodic does just call clockevents_set_mode, but nothing
to set a period.

Am I supposed to assume some default period?  HZ?  (That's what hpet
seems to do.)

Is set_next_event only ever called if the timer is in ONESHOT mode?

Thanks,
    J

             reply	other threads:[~2007-03-09 23:26 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-03-09 23:26 Jeremy Fitzhardinge [this message]
2007-03-10  8:41 ` question about periodic clocks Thomas Gleixner
2007-03-10 15:50   ` Jeremy Fitzhardinge
2007-03-10 16:24     ` Thomas Gleixner
2007-03-10 16:37       ` Jeremy Fitzhardinge

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=45F1ED30.5070402@goop.org \
    --to=jeremy@goop.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=tglx@linutronix.de \
    /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