From owner-freebsd-smp Thu Jan 3 3:43:37 2002 Delivered-To: freebsd-smp@freebsd.org Received: from critter.freebsd.dk (esplanaden.cybercity.dk [212.242.40.114]) by hub.freebsd.org (Postfix) with ESMTP id 600EB37B405; Thu, 3 Jan 2002 03:43:28 -0800 (PST) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.11.6/8.11.6) with ESMTP id g039Gr600685; Thu, 3 Jan 2002 10:16:53 +0100 (CET) (envelope-from phk@critter.freebsd.dk) To: Josef Karthauser Cc: Bosko Milekic , freebsd-arch@FreeBSD.ORG, freebsd-smp@FreeBSD.ORG Subject: Re: SMPng: Interrupt Latency Issues In-Reply-To: Your message of "Wed, 02 Jan 2002 19:02:53 GMT." <20020102190253.B47550@tao.org.uk> Date: Thu, 03 Jan 2002 10:16:53 +0100 Message-ID: <683.1010049413@critter.freebsd.dk> From: Poul-Henning Kamp Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org In message <20020102190253.B47550@tao.org.uk>, Josef Karthauser writes: >> It has become obvious, recently in particular, that some important >> improvements are required in the way we take interrupts in -CURRENT >> SMPng. As previously mentionned, we are experiencing lousy interrupt >> latency in -CURRENT. This comes as no surprise. > >I'm interested in helping with with, although my experience in this >area is zero ;(. I was waiting with bated breath for answers to >this email and am a bit disappointed that no-one's replied. I hope >that doesn't mean that it's not important to anyone. (I was hoping >to learn something :) I think it takes more than a few days to answer meaningfully to something that abstract (I'm sure our local superhero will jump in now and explain how he solved all of this back in the mid eighties on his Amiga :-) There are basically two things to getting good interrupt latency: 1. An architecture making it possible. 2. Care in coding all over the place. I think we are on track to #1. My main contribution will probably be in trying to establish a metrology to document the result, but to the extent time allows I will participate and help where I can. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message