From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1XxzV9-0002X1-IL for ltp-list@lists.sourceforge.net; Mon, 08 Dec 2014 14:41:27 +0000 Received: from e8.ny.us.ibm.com ([32.97.182.138]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1XxzV8-00083U-Hr for ltp-list@lists.sourceforge.net; Mon, 08 Dec 2014 14:41:27 +0000 Received: from /spool/local by e8.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 8 Dec 2014 09:41:21 -0500 Received: from b01cxnp22034.gho.pok.ibm.com (b01cxnp22034.gho.pok.ibm.com [9.57.198.24]) by d01dlp03.pok.ibm.com (Postfix) with ESMTP id 6D279C90052 for ; Mon, 8 Dec 2014 09:32:51 -0500 (EST) Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by b01cxnp22034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id sB8EemXC15990788 for ; Mon, 8 Dec 2014 14:40:48 GMT Received: from d01av03.pok.ibm.com (localhost [127.0.0.1]) by d01av03.pok.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id sB8EelSC031798 for ; Mon, 8 Dec 2014 09:40:47 -0500 Received: from localhost.localdomain ([9.125.24.218]) by d01av03.pok.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id sB8EekO2031730 for ; Mon, 8 Dec 2014 09:40:47 -0500 Date: Mon, 8 Dec 2014 21:52:50 +0800 From: Han Pingtian Message-ID: <20141208135250.GC3352@localhost.localdomain> References: <20141206012422.GA3352@localhost.localdomain> <20141208120922.GD11071@rei.suse.de> <20141208130301.GB3352@localhost.localdomain> <20141208131931.GB13319@rei.suse.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20141208131931.GB13319@rei.suse.de> Subject: Re: [LTP] questions about getrusage04 List-Id: Linux Test Project General Discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-list-bounces@lists.sourceforge.net To: ltp-list@lists.sourceforge.net On Mon, Dec 08, 2014 at 02:19:31PM +0100, Cyril Hrubis wrote: > Hi! > > > It tests timer precision for getrusage timers. If the timers are > > > incremting by larger values than expected, something is wrong in kernel. > > > The precision depends on CONFIG_HZ settings which is represented by the > > > BIAS_MAX. > > Where does the 1000 come from? If on a slow system, we need to increase > > the "factor_nr", right? > > The factor is set to 1 and it shouldn't needed to change that. > > > > > And looks like with this patch applied, it works well on powerpc: > > > > > > Can you please share the output of the testcase on ppc and ppc64? What > > > is the expected timer granularity there? > > > > > Looks like the granularity is 10000us: > > > > getrusage04 0 TINFO : Expected timers granularity is 10000 us > > getrusage04 0 TINFO : Using 1 as multiply factor for max [us]time increment (1000+10000us)! > > getrusage04 0 TINFO : utime: 56us; stime: 1192us > > getrusage04 0 TINFO : utime: 56us; stime: 2009us > > getrusage04 0 TINFO : utime: 56us; stime: 4233us > > getrusage04 0 TINFO : utime: 1227us; stime: 5243us > > getrusage04 0 TINFO : utime: 1227us; stime: 8541us > > getrusage04 0 TINFO : utime: 2072us; stime: 8741us > > getrusage04 0 TINFO : utime: 2602us; stime: 11169us > > getrusage04 0 TINFO : utime: 2743us; stime: 11747us > > getrusage04 0 TINFO : utime: 2948us; stime: 12790us > > getrusage04 0 TINFO : utime: 2948us; stime: 18118us > > getrusage04 0 TINFO : utime: 2948us; stime: 18596us > > getrusage04 0 TINFO : utime: 4458us; stime: 20030us > > getrusage04 0 TINFO : utime: 4458us; stime: 20244us > > getrusage04 0 TINFO : utime: 4458us; stime: 23432us > > getrusage04 0 TINFO : utime: 5412us; stime: 24650us > > getrusage04 0 TINFO : utime: 5412us; stime: 27273us > > getrusage04 0 TINFO : utime: 6125us; stime: 27909us > > getrusage04 0 TINFO : utime: 6125us; stime: 27911us > > getrusage04 0 TINFO : utime: 6125us; stime: 28111us > > getrusage04 0 TINFO : utime: 6235us; stime: 28513us > > getrusage04 0 TINFO : utime: 6235us; stime: 28750us > > getrusage04 1 TPASS : Test Passed > > Hmm, this looks like the granularity of the timer is much smaller than > 10000us and it varies greatly between measurements. Is this CONFIG_NO_HZ > system? Yes, looks like it is: % grep CONFIG_NO_HZ /boot/config-2.6.32-504.el6.ppc64 CONFIG_NO_HZ=y ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=164703151&iu=/4140/ostg.clktrk _______________________________________________ Ltp-list mailing list Ltp-list@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ltp-list