From: tony@bakeyournoodle•com (Tony Breeds)
To: Daniel Walker <dwalker@mvista•com>
Cc: Andrew Morton <akpm@osdl•org>, john stultz <johnstul@us•ibm.com>,
LKML <linux-kernel@vger•kernel.org>,
LinuxPPC-dev <linuxppc-dev@ozlabs•org>,
Thomas Gleixner <tglx@linutronix•de>, Ingo Molnar <mingo@elte•hu>
Subject: Re: [RFC] clocksouce implementation for powerpc
Date: Fri, 22 Jun 2007 16:23:05 +1000 [thread overview]
Message-ID: <20070622062305.GX9768@bakeyournoodle.com> (raw)
In-Reply-To: <1182351439.18168.79.camel@imap.mvista.com>
On Wed, Jun 20, 2007 at 07:57:19AM -0700, Daniel Walker wrote:
Hi Daniel.
> As I said in our private thread, I do think you should be using
> update_vsyscall() .. update_vsyscall() is just called when the time is
> set, usually that happens in the timer interrupt and sometimes that
> happens in settimeofday() ..
Well I've taken another look at the code and I think I can probably
restructure my code to use update_vsyscall(). I thought I needed a
hook that was called /only/ from settimeofday() (which as you say
doesn't match update_vsyscall()'s usage).
I'll try again and see what problems I hit.
> At least some of your code is duplications over what is already being
> worked on inside the powerpc community.. For instance, I know there is
> already a timebase clocksource,
>
> http://people.redhat.com/~mingo/realtime-preempt/patch-2.6.21.5-rt17
Thanks. The one in -rt doesn't seem to support the VDSO. however I see
that there is duplication of effort there.
> Hmm .. This doesn't look like it's taking into account that the time has
> changed .. Your time has effectively incremented by one jiffie .. The
> vdso_data doesn't appear to be updated ..
Unless I miss your meaning, the vdso is updated in
timer_recalc_offset()/update_gtod() when needed.
Yours Tony
linux.conf.au http://linux.conf.au/ || http://lca2008.linux.org.au/
Jan 28 - Feb 02 2008 The Australian Linux Technical Conference!
next prev parent reply other threads:[~2007-06-22 6:23 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20070616101126.296384219@inhelltoy.tec.linutronix.de>
[not found] ` <20070616101637.107940593@inhelltoy.tec.linutronix.de>
[not found] ` <1182009083.11539.369.camel@imap.mvista.com>
2007-06-20 6:57 ` [RFC] clocksouce implementation for powerpc Tony Breeds
2007-06-20 14:57 ` Daniel Walker
2007-06-20 17:20 ` Sergei Shtylyov
2007-06-20 17:31 ` Thomas Gleixner
2007-06-20 18:11 ` Sergei Shtylyov
2007-06-22 6:23 ` Tony Breeds [this message]
2007-06-20 16:53 ` Sergei Shtylyov
2007-06-22 6:10 ` Tony Breeds
2007-06-22 12:42 ` Sergei Shtylyov
2007-06-20 21:06 ` john stultz
2007-06-22 6:28 ` Tony Breeds
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=20070622062305.GX9768@bakeyournoodle.com \
--to=tony@bakeyournoodle$(echo .)com \
--cc=akpm@osdl$(echo .)org \
--cc=dwalker@mvista$(echo .)com \
--cc=johnstul@us$(echo .)ibm.com \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=linuxppc-dev@ozlabs$(echo .)org \
--cc=mingo@elte$(echo .)hu \
--cc=tglx@linutronix$(echo .)de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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