From owner-freebsd-current@FreeBSD.ORG Wed Jun 22 15:12:46 2005 Return-Path: X-Original-To: freebsd-current@freebsd.org Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D03D916A41C for ; Wed, 22 Jun 2005 15:12:46 +0000 (GMT) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [204.156.12.53]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4BB6443D49 for ; Wed, 22 Jun 2005 15:12:45 +0000 (GMT) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [204.156.12.50]) by cyrus.watson.org (Postfix) with ESMTP id D658846B33; Wed, 22 Jun 2005 11:12:44 -0400 (EDT) Date: Wed, 22 Jun 2005 16:15:49 +0100 (BST) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: Emanuel Strobl In-Reply-To: <200506221659.36667@harrymail> Message-ID: <20050622160558.C82703@fledge.watson.org> References: <200506091423.39940@harrymail> <200506221606.42862@harrymail> <20050622154538.H26664@fledge.watson.org> <200506221659.36667@harrymail> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-current@freebsd.org Subject: Re: lapic@2k interrukts eating CPU cycles X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 22 Jun 2005 15:12:46 -0000 On Wed, 22 Jun 2005, Emanuel Strobl wrote: >> Might have been John Baldwin. > > Hm, me and names is a weak point... ;) Not as bad as me, I promise. One someone introduces themselves at a conference, I'll literally forget their name by the end of the sentence where they say it. I'll remember them, but their name will be gone really quickly. Very embarrassing :-). >> I have a feature request in to John to add statistics gathering on IPIs, >> since he's currently reworking the interrupt paths. > > Thanks so much, very good explanation, I almost understood it completely > (I'm lacking a lot of basics). If only "The Design and Implementation of > the FreeBSD Operating System" was written like this... If the D&I book were written this way, it would come in three volumes :-). Part of the problem here is that we weren't exposing some of the internal behavior via monitoring interfaces, so what was a rearrangement of functionality in the kernel was less well represented in the monitoring. So I think the answer there is to improve our monitoring so it's more clear what's going on. I'm currently working on enhanced versions of vmstat and some other tools to allow better per-cpu monitoring of memory load/allocation, and we should do something similar to interrupt monitoring, add IPI monitoring, and so on. Robert N M Watson