From: Thomas Gleixner <tglx@linutronix.de>
To: george@mvista.com
Cc: "Davda, Bhavesh P (Bhavesh)" <bhavesh@avaya.com>,
Chris Friesen <cfriesen@nortel.com>,
linux-kernel@vger.kernel.org
Subject: Re: 2.6.11 timeval_to_jiffies() wrong for ms resolution timers
Date: Wed, 25 May 2005 23:41:40 +0200 [thread overview]
Message-ID: <1117057300.6736.324.camel@tglx.tec.linutronix.de> (raw)
In-Reply-To: <4294D9C6.3060501@mvista.com>
On Wed, 2005-05-25 at 13:02 -0700, George Anzinger wrote:
> We ARE trying to get this into the main line, but save the patch, there is no
> way to get millisecond accuracy in the kernel OR in user land. Never has been!
> That is why the patch exists. There was an effort by some university folks
> prior to the HRT stuff, but AFAIK it is not supported or uptodate.
It's up to date and supported, if you are talking about the KURT
project. Just the website is hopelessly out of date.
> As for jiffies vs time, my understanding from senior time folks is that 1/HZ as
> a resolution is just an approximation. We do the best we can but the x86 is
> really the PITs (pun intended) when it comes to time keeping resources. If you
> really want millisecond accuracy, you may need to consider another platform....
Why so ? Accepted PIT, is a PITA due to the ISA access penalty, but it
still allows you to run timers below millisecond accuracy.
tglx
next prev parent reply other threads:[~2005-05-25 21:41 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-05-25 19:06 Davda, Bhavesh P (Bhavesh)
2005-05-25 20:02 ` George Anzinger
2005-05-25 21:41 ` Thomas Gleixner [this message]
2005-05-26 17:04 ` Olivier Croquette
2005-05-26 18:10 ` Richard B. Johnson
2005-05-26 18:19 ` Lee Revell
2005-05-26 19:24 ` George Anzinger
2005-05-26 19:32 ` Lee Revell
-- strict thread matches above, loose matches on Subject: below --
2005-05-25 19:16 Davda, Bhavesh P (Bhavesh)
2005-05-24 22:59 Bhavesh P. Davda
2005-05-25 17:21 ` George Anzinger
2005-05-25 17:37 ` Chris Friesen
2005-05-25 17:54 ` George Anzinger
2005-05-25 18:07 ` Chris Friesen
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=1117057300.6736.324.camel@tglx.tec.linutronix.de \
--to=tglx@linutronix.de \
--cc=bhavesh@avaya.com \
--cc=cfriesen@nortel.com \
--cc=george@mvista.com \
--cc=linux-kernel@vger.kernel.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
all inboxes | Powered by JetHome®