From: Dave Johnson <djohnson+linux-kernel@sw.starentnetworks.com>
To: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Cc: Ingo Molnar <mingo@elte.hu>,
linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>, Greg KH <gregkh@suse.de>,
Chris Wright <chrisw@sous-sol.org>
Subject: Re: [PATCH] i386: fix TSC clock source calibration error [part 2]
Date: Fri, 19 Oct 2007 14:34:56 -0400 [thread overview]
Message-ID: <18200.63696.399763.437303@zeus.sw.starentnetworks.com> (raw)
In-Reply-To: <4718F0DE.3050207@ct.jp.nec.com>
Hiroshi Shimamoto writes:
> Dave Johnson wrote:
> > mach_prepare_counter();
>
> It's a really rare case, but if SMI interrupt takes CPU here, just after
> prepare and before rdtscll, it makes delta64 shorter than expected one.
> Is it possible? And how about moving rdtscll before mach_prepare_counter()?
>
> > rdtscll(start);
Yep, rare indeed (about 1 instruction). Moving the start read before
the prepare call should solve that one too providing the setup doesn't
take any real measurable time.
--
Dave Johnson
Starent Networks
next prev parent reply other threads:[~2007-10-19 18:35 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-16 14:50 [PATCH] i386: fix TSC clock source calibration error Dave Johnson
2007-10-16 15:11 ` Chuck Ebbert
2007-10-18 8:57 ` Ingo Molnar
2007-10-19 17:16 ` [PATCH] i386: fix TSC clock source calibration error [part 2] Dave Johnson
2007-10-19 18:01 ` Hiroshi Shimamoto
2007-10-19 18:34 ` Dave Johnson [this message]
2007-10-22 11:42 ` Ingo Molnar
2007-10-18 20:43 ` [PATCH] i386: fix TSC clock source calibration error Daniel Walker
2007-10-19 17:31 ` Dave Johnson
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=18200.63696.399763.437303@zeus.sw.starentnetworks.com \
--to=djohnson+linux-kernel@sw.starentnetworks.com \
--cc=chrisw@sous-sol.org \
--cc=gregkh@suse.de \
--cc=h-shimamoto@ct.jp.nec.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--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
all inboxes | Powered by JetHome®