Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 27 Mar 2001 13:24:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 27 Mar 2001 13:24:19 -0500 Received: from f48.law14.hotmail.com ([64.4.21.48]:12813 "EHLO hotmail.com") by vger.kernel.org with ESMTP id ; Tue, 27 Mar 2001 13:24:03 -0500 X-Originating-IP: [12.44.186.158] From: "Dinesh Nagpure" To: moz@compsoc.man.ac.uk Cc: linux-kernel@vger.kernel.org Subject: Re: hooking APIC timer doesnt work? Date: Tue, 27 Mar 2001 10:23:17 -0800 Mime-Version: 1.0 Content-Type: text/plain; format=flowed Message-ID: X-OriginalArrivalTime: 27 Mar 2001 18:23:17.0316 (UTC) FILETIME=[FE675040:01C0B6EA] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org John, First of all let me thank you for pointing to Vincent Oberle's APIC timer module, I am trying to understand how the timer is hooked in it. BTW forgive my ignorance but what is oprofile? the reason I am trying to hook perfctr is, well let me tell you what I am trying to do here, I want to measure time spent between a cli and the corresponding sti, I am using the performance monitoring event CYCLES_INT_MASKED and setting the perfctr MSR to overflow on the first cycle after a cli, this overflow will generate PCINT from the APIC which I am programming in delivery mode NMI, here I will take my initial TSC reading, and also program the APIC timer initial count register to to trigger on the next clock, but this timer interrupt will be kept pending as long as the interrupts are disabled in the system, and will get serviced after a sti occurs, here I take my second TSC reading, any comments? Dinesh ----Original Message Follows---- From: John Levon To: Dinesh Nagpure CC: linux-kernel@vger.kernel.org Subject: Re: hooking APIC timer doesnt work? Date: Tue, 27 Mar 2001 12:38:01 +0100 (BST) On Mon, 26 Mar 2001, Dinesh Nagpure wrote: > Hello all, > I am trying to use the LAPIC timer to generate interrupt for some kernel > profiling work I am doing...but the timer ISR isnt invoking atall....here is > what I have done.... > Have you seen Vincent Oberle's APIC timers module ? There is a link at kernelnewbies.org Also, what are you doing with the perfctr interrupt ? Are you aware of perfctr and oprofile ? john -- "Stop telling God what to do." - Niels Bohr _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com - 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/