mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: GolovaSteek <golovasteek@gmail.com>
To: linux-kernel@vger.kernel.org
Subject: nanosleep() accuracy
Date: Fri, 17 Aug 2007 02:52:03 +0400	[thread overview]
Message-ID: <f40fb4250708161552ub87bf8ve8168eec1b3955e7@mail.gmail.com> (raw)

Hello!
I need use sleep with accurat timing.
I use 2.6.21 with rt-prempt patch.
with enabled rt_preempt, dyn_ticks, and local_apic
But

req.tv_nsec = 300000;
req.tv_sec = 0;
nanosleep(&req,NULL)

make pause around 310-330 microseconds.

I tried to understend how work nanosleep(), but it not depends from
jiffies and from smp_apic_timer_interrupt.

When can accuracy be lost?
And how are process waked up?


GolovaSteek

             reply	other threads:[~2007-08-16 22:52 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-08-16 22:52 GolovaSteek [this message]
2007-08-17  7:00 ` Michal Schmidt
2007-08-17  7:44   ` GolovaSteek
2007-08-17  7:54     ` Jan Engelhardt
2007-08-17 11:08     ` Michal Schmidt

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=f40fb4250708161552ub87bf8ve8168eec1b3955e7@mail.gmail.com \
    --to=golovasteek@gmail.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®