From: Andrew Morton <akpm@linux-foundation.org>
To: john stultz <johnstul@us.ibm.com>
Cc: Daniel Walker <dwalker@mvista.com>,
linux-kernel@vger.kernel.org, mingo@elte.hu
Subject: Re: [PATCH] timekeeping: drop irq-context clocksource polling
Date: Thu, 5 Apr 2007 14:36:41 -0700 [thread overview]
Message-ID: <20070405143641.a751f43e.akpm@linux-foundation.org> (raw)
In-Reply-To: <1175808319.28526.26.camel@localhost>
On Thu, 05 Apr 2007 14:25:19 -0700
john stultz <johnstul@us.ibm.com> wrote:
> On Thu, 2007-04-05 at 14:03 -0700, Daniel Walker wrote:
> > Before this change the timekeeping code would poll the clocksource
> > list every interrupt. This changes that so the clocksource list is
> > only checked when there has been and update, and no longer checks
> > in interrupt context.
> >
> > This also has a few small space and line cleanups.
> >
> > Boot tested on i386, compile tested on x86_64 .. However, I couldn't
> > find a !GENERIC_TIME that compiled without this change so it's untested..
> >
> > Signed-Off-By: Daniel Walker <dwalker@mvista.com>
>
> Err.. I think you need to be holding a write on the xtime_lock (as is
> done before calling update_wall_time()) when changing the clocksource.
The patch does add the appropriate locking to change_clocksource(),
doesn't it?
It looks like a good change to me - we avoid taking the kernel-wide
clocksource_lock every tick?
next prev parent reply other threads:[~2007-04-05 21:36 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-05 21:03 [PATCH] timekeeping: drop irq-context clocksource polling Daniel Walker
2007-04-05 21:25 ` john stultz
2007-04-05 21:29 ` Daniel Walker
2007-04-05 21:38 ` john stultz
2007-04-05 21:36 ` Andrew Morton [this message]
2007-04-05 21:50 ` john stultz
2007-04-07 1:21 ` Andrew Morton
2007-04-07 2:04 ` Daniel Walker
2007-04-07 10:19 ` Andrew Morton
2007-04-07 17:43 ` Daniel Walker
2007-04-07 20:50 ` Thomas Gleixner
2007-04-07 21:30 ` Daniel Walker
2007-04-08 8:33 ` Thomas Gleixner
2007-04-08 20:02 ` Daniel Walker
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=20070405143641.a751f43e.akpm@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=dwalker@mvista.com \
--cc=johnstul@us.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
/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