From owner-freebsd-hackers Fri Feb 1 0:28:39 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by hub.freebsd.org (Postfix) with ESMTP id 5884A37B400 for ; Fri, 1 Feb 2002 00:28:36 -0800 (PST) Received: by elvis.mu.org (Postfix, from userid 1192) id EE21D10DDFD; Fri, 1 Feb 2002 00:28:35 -0800 (PST) Date: Fri, 1 Feb 2002 00:28:35 -0800 From: Alfred Perlstein To: Luigi Rizzo Cc: Terry Lambert , Mike Silbersack , Storms of Perfection , thierry@herbelot.com, replicator@ngs.ru, hackers@FreeBSD.org Subject: Re: Clock Granularity (kernel option HZ) Message-ID: <20020201002835.I18604@elvis.mu.org> References: <20020131172729.X38382-100000@patrocles.silby.com> <3C59E873.4E8A82B5@mindspring.com> <20020201002339.C48439@iguana.icir.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20020201002339.C48439@iguana.icir.org>; from rizzo@icir.org on Fri, Feb 01, 2002 at 12:23:39AM -0800 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG * Luigi Rizzo [020201 00:25] wrote: > On Thu, Jan 31, 2002 at 04:59:31PM -0800, Terry Lambert wrote: > > > > You will get a factor of 6 (approximately) improvement in > > throughput vs. overhead if you process packets to completion > > at interrupt, and process writes to completion at write time > > from the process. > > this does not match my numbers. e.g. using "fastforwarding" > (which bypasses netisrs's) improves peak throughput > by a factor between 1.2 and 2 on our test boxes. Forwarding packets is a lot less complicated than doing tcp recieve and send. I haven't seen Terry's stuff in action, however it makes sense that tcp would see more of an improvement than simple IP forwarding. -Alfred To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message