public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Roland Dreier <roland@topspin.com>
To: Robin Holt <holt@sgi.com>
Cc: "Richard B. Johnson" <root@chaos.analogic.com>,
	Dean Nelson <dcn@sgi.com>, Arjan van de Ven <arjanv@redhat.com>,
	linux-kernel@vger.kernel.org, rusty@rustcorp.com.au
Subject: Re: calling kthread_create() from interrupt thread
Date: 15 Jun 2004 12:28:51 -0700	[thread overview]
Message-ID: <52u0xcwrgs.fsf@topspin.com> (raw)
In-Reply-To: <20040615190114.GA6151@lnx-holt.americas.sgi.com>

    Robin> The problem Dean is trying to address is as follows:

    Robin> We receive an interrupt.  The interrupt handler determines
    Robin> that some work needs to be done.  Part of that work to be
    Robin> done may result in the process needing to go to sleep
    Robin> waiting for a resource to become available.

    Robin> Currently, the interrupt handler wakes a thread sleeping on
    Robin> a wait_event_interruptible().  This wakeup is taking approx
    Robin> 35uSec.  Dean is looking for a lower latency means of doing
    Robin> the wakeup.

Could the interrupt handler attempt to do the work directly, and only
defer things if it determines it needs to sleep for the resource?  It
seems if your are sleeping waiting for something to free up, then
your latency is shot anyway.

 - Roland

  reply	other threads:[~2004-06-15 19:29 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-06-15 17:42 calling kthread_create() from interrupt thread Dean Nelson
2004-06-15 17:49 ` Arjan van de Ven
2004-06-15 18:05   ` Dean Nelson
2004-06-15 18:14     ` Jesse Barnes
2004-06-15 22:14       ` Jeff Garzik
2004-06-15 18:15     ` Richard B. Johnson
2004-06-15 19:01       ` Robin Holt
2004-06-15 19:28         ` Roland Dreier [this message]
2004-06-15 19:30         ` Chris Wright
2004-06-15 23:40         ` Rusty Russell
2004-06-15 19:14   ` Dean Nelson
2004-06-15 19:27     ` Roland Dreier
2004-06-15 19:59     ` Chris Wright
     [not found] <27qex-5LX-17@gated-at.bofh.it>
     [not found] ` <27qoT-5Uy-15@gated-at.bofh.it>
     [not found]   ` <27qxQ-67a-27@gated-at.bofh.it>
2004-06-15 20:41     ` Andi Kleen

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=52u0xcwrgs.fsf@topspin.com \
    --to=roland@topspin.com \
    --cc=arjanv@redhat.com \
    --cc=dcn@sgi.com \
    --cc=holt@sgi.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=root@chaos.analogic.com \
    --cc=rusty@rustcorp.com.au \
    /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