Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932405AbWEQBPH (ORCPT ); Tue, 16 May 2006 21:15:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932407AbWEQBPG (ORCPT ); Tue, 16 May 2006 21:15:06 -0400 Received: from mail07.syd.optusnet.com.au ([211.29.132.188]:17854 "EHLO mail07.syd.optusnet.com.au") by vger.kernel.org with ESMTP id S932405AbWEQBPF (ORCPT ); Tue, 16 May 2006 21:15:05 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17514.30904.648888.894039@wombat.chubb.wattle.id.au> Date: Wed, 17 May 2006 11:13:28 +1000 From: Peter Chubb To: Martin Peschke Cc: Andrew Morton , linux-kernel@vger.kernel.org, ak@suse.de, hch@infradead.org, arjan@infradead.org, James.Smart@emulex.com, James.Bottomley@steeleye.com Subject: Re: [RFC] [Patch 7/8] statistics infrastructure - exploitation prerequisite In-Reply-To: <446A53DE.6060400@de.ibm.com> References: <446A1023.6020108@de.ibm.com> <20060516112824.39b49563.akpm@osdl.org> <446A53DE.6060400@de.ibm.com> X-Mailer: VM 7.17 under 21.4 (patch 17) "Jumbo Shrimp" XEmacs Lucid Comments: Hyperbole mail buttons accepted, v04.18. X-Face: GgFg(Z>fx((4\32hvXq<)|jndSniCH~~$D)Ka:P@e@JR1P%Vr}EwUdfwf-4j\rUs#JR{'h# !]])6%Jh~b$VA|ALhnpPiHu[-x~@<"@Iv&|%R)Fq[[,(&Z'O)Q)xCqe1\M[F8#9l8~}#u$S$Rm`S9% \'T@`:&8>Sb*c5d'=eDYI&GF`+t[LfDH="MP5rwOO]w>ALi7'=QJHz&y&C&TE_3j! Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1425 Lines: 31 >>>>> "Martin" == Martin Peschke writes: Martin> I would be happy to exploit an API that may result from that Martin> discussion. I would plead for exporting such an API to Martin> modules. I don't see how to implement statistics for Martin> latencies, otherwise. Martin> Any other hints on how to replace my sched_clock() calls are Martin> welcome. (I want to measure elapsed times in units that are Martin> understandable to users without hardware manuals and Martin> calculator, such as milliseconds.) You may wish to look at the microstate accounting patches at http://www.gelato.unsw.edu.au/cgi-bin/viewcvs.cgi/cvs/kernel/microstate/ I made the clock source configurable. It's acually rather difficult to find a reliable cross-platform monotonic clock with good resolution. And different statistics may want different clocks; for my purposes a cycle counter is best (because I'm running on a machine that varies the clock speed for power management reasons), other people may want nanoseconds. -- Dr Peter Chubb http://www.gelato.unsw.edu.au peterc AT gelato.unsw.edu.au http://www.ertos.nicta.com.au ERTOS within National ICT Australia - 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/