mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Sebastian Heidl <heidl@zib.de>
To: Manfred Spraul <manfred@colorfullife.com>
Cc: lkml <linux-kernel@vger.kernel.org>
Subject: Re: doing a callback from the kernel to userspace
Date: Tue, 13 Nov 2001 10:47:20 +0100	[thread overview]
Message-ID: <20011113104720.D5446@csr-pc1.zib.de> (raw)
In-Reply-To: <001a01c16ba7$ab5242d0$010411ac@local>
In-Reply-To: <001a01c16ba7$ab5242d0$010411ac@local>; from manfred@colorfullife.com on Mon, Nov 12, 2001 at 07:27:14PM +0100

On Mon, Nov 12, 2001 at 07:27:14PM +0100, Manfred Spraul wrote:
> The latency you talk about is the time required to schedule - there is nothing
> you driver can do to reduce that - syscall, signal or your own code must wait
> until schedule() decides to run your process.
> 
> I'd try to
> a) switch your process to realtime priority, mlockall your app.
> b) use the low-latency patches. They were regularly discussed on
> linux-kernel, search through the archives.
i'll definitely hav a look at these patches, thanks

> 
> Are you sure you need 10 to 20 usec? Then a hard realtime with everything
> in kernel is your only option, i.e. rtlinux.
Yes I'm sure and no, I don't think rtlinux is necessary, see my post answering
Richard.

thanks again, maybe the ll-patches and some priority shifting is all I need
_sh_


  reply	other threads:[~2001-11-13  9:47 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-11-12 18:27 Manfred Spraul
2001-11-13  9:47 ` Sebastian Heidl [this message]
  -- strict thread matches above, loose matches on Subject: below --
2001-11-12 17:05 Sebastian Heidl
2001-11-12 18:39 ` Richard B. Johnson
2001-11-13  9:47   ` Sebastian Heidl

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=20011113104720.D5446@csr-pc1.zib.de \
    --to=heidl@zib.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=manfred@colorfullife.com \
    /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®