Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751885Ab1DQIbG (ORCPT ); Sun, 17 Apr 2011 04:31:06 -0400 Received: from am1ehsobe004.messaging.microsoft.com ([213.199.154.207]:59437 "EHLO AM1EHSOBE004.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751447Ab1DQIbA (ORCPT ); Sun, 17 Apr 2011 04:31:00 -0400 X-Greylist: delayed 903 seconds by postgrey-1.27 at vger.kernel.org; Sun, 17 Apr 2011 04:31:00 EDT X-SpamScore: -5 X-BigFish: VPS-5(zzbb2cK98dKzz1202hzzz32i637h668h839h61h) X-Spam-TCS-SCL: 0:0 X-Forefront-Antispam-Report: KIP:(null);UIP:(null);IPVD:NLI;H:ausb3twp01.amd.com;RD:none;EFVD:NLI X-WSS-ID: 0LJSEY7-01-DQ3-02 X-M-MSG: Date: Sun, 17 Apr 2011 10:15:40 +0200 From: Robert Richter To: Peter Zijlstra CC: Ingo Molnar , Stephane Eranian , LKML Subject: Re: [PATCH 4/4] perf, x86: Fix event scheduler to solve complex scheduling problems Message-ID: <20110417081540.GL31407@erda.amd.com> References: <1302913676-14352-1-git-send-email-robert.richter@amd.com> <1302913676-14352-5-git-send-email-robert.richter@amd.com> <1302943877.32491.9.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1302943877.32491.9.camel@twins> User-Agent: Mutt/1.5.20 (2009-06-14) X-OriginatorOrg: amd.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1417 Lines: 36 On 16.04.11 04:51:17, Peter Zijlstra wrote: > Argh, crap. That's because AMD is now the first with overlapping > constraints. Be sure to let your hardware guys know that they went from > top to bottom om my appreciation list. AMD used to have no constraints > and now they have the absolute worst. Yes, the overlapping constraints are the problem. > I'd really prefer not to do this for .39, and I'll have to sit down and > actually read this code. It looks like we went from O(n^2) to O(n!) or > somesuch, also not much of an improvement. I'll have to analyze the > solver to see what it does for 'simple' constraints set to see if it > will indeed be more expensive than the O(n^2) solver we had. It wont be more expensive, if there is a solution. But if there is no one we walk all possible ways now which is something like O(n!). Yes, we can shift this general solution after .39. Will try to find a solution that handles the special case for family 15h as a fix for .39. > Also, I think this code could do with a tiny bit of comments ;-) Will comment on the code inline in the patch. -Robert -- Advanced Micro Devices, Inc. Operating System Research Center -- 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/