From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1IpSlA-0006FZ-LJ for user-mode-linux-devel@lists.sourceforge.net; Tue, 06 Nov 2007 10:02:44 -0800 Received: from [198.99.130.12] (helo=saraswathi.solana.com) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1IpSl6-0003zb-HA for user-mode-linux-devel@lists.sourceforge.net; Tue, 06 Nov 2007 10:02:44 -0800 Date: Tue, 6 Nov 2007 13:02:30 -0500 From: Jeff Dike Message-ID: <20071106180230.GA13370@c2.user-mode-linux.org> References: <1f154f440710161936h4800b0c5nb3140ff504212625@mail.gmail.com> <20071017155504.GD9497@c2.user-mode-linux.org> <1f154f440710170916j4fdb857fw40c9b2fd2b66f63f@mail.gmail.com> <20071017171920.GA10388@c2.user-mode-linux.org> <1f154f440710171243x40898f8bq386c91c59789fb42@mail.gmail.com> Mime-Version: 1.0 Content-Disposition: inline In-Reply-To: <1f154f440710171243x40898f8bq386c91c59789fb42@mail.gmail.com> Subject: Re: [uml-devel] Dramatic drop in C3 state residency with NO_HZ patches List-Id: The user-mode Linux development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: user-mode-linux-devel-bounces@lists.sourceforge.net Errors-To: user-mode-linux-devel-bounces@lists.sourceforge.net To: Hrishikesh Cc: user-mode-linux-devel@lists.sourceforge.net On Wed, Oct 17, 2007 at 03:43:01PM -0400, Hrishikesh wrote: > for the case where the kernel is patched, but NO_HZ is __not__ enabled, > there is a do_nanosleep() every 100 or so us. > > setitimer(ITIMER_VIRTUAL, {it_interval={0, 0}, it_value={0, 0}}, > {it_interval={0, 0}, it_value={0, 0}}) = 0 > nanosleep({0, 0}, {0, 0}) = 0 Can you reproduce this with current mainline? I can't: 1194371604.120203 setitimer(ITIMER_VIRTUAL, {it_interval={0, 0}, it_value={0, 10000}}, NULL) = 0 1194371604.120256 setitimer(ITIMER_VIRTUAL, {it_interval={0, 0}, it_value={0, 0}}, {it_interval={0, 0}, it_value={0, 11998}}) = 0 1194371604.120306 nanosleep({0, 11998000}, {0, 11998000}) = 0 It's correctly reading the current alarm and sleeping for that long. It could be more efficient, but this isn't a busy loop. Jeff -- Work email - jdike at linux dot intel dot com ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel