Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764942AbXHPWwU (ORCPT ); Thu, 16 Aug 2007 18:52:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755580AbXHPWwJ (ORCPT ); Thu, 16 Aug 2007 18:52:09 -0400 Received: from wr-out-0506.google.com ([64.233.184.226]:2691 "EHLO wr-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754281AbXHPWwF (ORCPT ); Thu, 16 Aug 2007 18:52:05 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=gvwtJJmTk6CPLr3u1l1ZZXh9sUnj0joCJ88JdX/X6WQvNYjcEhZnl5r/Bk5hHrnijuaxj7uDVEdIPmx5sD4Wd128tbgh98iYLlsgK2X9EMqfMrImSDjF86O1IZadbJhEslWvLIT2KCleBAIGRn//e5/gJ57DWlPp2z7lg/FoooE= Message-ID: Date: Fri, 17 Aug 2007 02:52:03 +0400 From: GolovaSteek To: linux-kernel@vger.kernel.org Subject: nanosleep() accuracy MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 664 Lines: 25 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 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/