From owner-freebsd-arch Tue Dec 18 14:56: 8 2001 Delivered-To: freebsd-arch@freebsd.org Received: from iguana.aciri.org (iguana.aciri.org [192.150.187.36]) by hub.freebsd.org (Postfix) with ESMTP id 5AA0F37B426 for ; Tue, 18 Dec 2001 14:55:52 -0800 (PST) Received: (from rizzo@localhost) by iguana.aciri.org (8.11.3/8.11.1) id fBIMtcg89913; Tue, 18 Dec 2001 14:55:38 -0800 (PST) (envelope-from rizzo) Date: Tue, 18 Dec 2001 14:55:38 -0800 From: Luigi Rizzo To: Bosko Milekic Cc: Jonathan Lemon , Bruce Evans , arch@FreeBSD.ORG Subject: Re: swi_net Message-ID: <20011218145538.A89864@iguana.aciri.org> References: <20011213091957.B39991@iguana.aciri.org> <20011219010205.P4481-100000@gamplex.bde.org> <20011218104750.M377@prism.flugsvamp.com> <20011218134149.A89299@iguana.aciri.org> <20011218175421.A37567@technokratis.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20011218175421.A37567@technokratis.com> User-Agent: Mutt/1.3.23i Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Tue, Dec 18, 2001 at 05:54:21PM -0500, Bosko Milekic wrote: ... > While we're on the subject, running the stack in interrupt context > seems to be an attempt to, mainly, remedy the load problem where we have > a lot of interrupts and the soft int thread doesn't even get a chance to > run... so we have a sort of livelock situation. For the cases that you yes that was the part I was in favour with... > describe, how effective do you think it would be to do as we presently > do and just schedule the soft net thread to run, return from the > interrupt but, when under load figure out a way to bump up the priority > of the softnetisr thread enough so that it does get a chance to run? the polling code in -current tries to do exacly this, and it is reasonbly self-adjusting: it grabs a small amount of packets from the interfaces, then processes the netisr to completion, then grabs more packets, and so on. Additionally, it guarantees that user tasks have a fraction of the CPU available, so if this traffic involves userland processing at least we avoid complete livelock. cheers luigi ----------------------------------+----------------------------------------- Luigi RIZZO, luigi@iet.unipi.it . ACIRI/ICSI (on leave from Univ. di Pisa) http://www.iet.unipi.it/~luigi/ . 1947 Center St, Berkeley CA 94704 Phone: (510) 666 2927 ----------------------------------+----------------------------------------- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message