From owner-freebsd-hackers@FreeBSD.ORG Mon Jun 22 00:35:56 2009 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2A6CF106564A for ; Mon, 22 Jun 2009 00:35:56 +0000 (UTC) (envelope-from pyunyh@gmail.com) Received: from mail-px0-f203.google.com (mail-px0-f203.google.com [209.85.216.203]) by mx1.freebsd.org (Postfix) with ESMTP id EC6058FC0C for ; Mon, 22 Jun 2009 00:35:55 +0000 (UTC) (envelope-from pyunyh@gmail.com) Received: by pxi41 with SMTP id 41so2230140pxi.3 for ; Sun, 21 Jun 2009 17:35:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:received:from:date:to:cc :subject:message-id:reply-to:references:mime-version:content-type :content-disposition:in-reply-to:user-agent; bh=swdXRg1JxhO869Rdrkciqcq9kco8P0Cccp36BwKeMws=; b=FrR8IBvAXEISx/W2a7JcXy5znh4cJ8W4HQC5xrm0gsCglQSiJAW6WFRBiQKy1kVUvu fqDiwUg+JQg48ysK7zsYvcIkznODFTY0TTmQidlDk1uF7rlRMN8l6j2eqDpb07qP0fCN RacKQj/ykwYb7qLKylUQSsnMrPONRx6dN6jUA= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:date:to:cc:subject:message-id:reply-to:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=pUqLod/kmhQUfk+eS+zMVDWlCab3UMdodz1x7GRqiEaOI0NcHVnUrQGJcn5miHPowv sV+gOLP6cUyOJ4Cg2/qg1BiDje9wogCRB7lgg/As12SVmtk7L6xgAQlunxNar1kiUnSq eckSze1h2SXGNWH8a++nnXkzISatp627XbuB8= Received: by 10.143.19.16 with SMTP id w16mr2355647wfi.343.1245629536522; Sun, 21 Jun 2009 17:12:16 -0700 (PDT) Received: from michelle.cdnetworks.co.kr ([114.111.62.249]) by mx.google.com with ESMTPS id 32sm8035wfc.34.2009.06.21.17.12.14 (version=SSLv3 cipher=RC4-MD5); Sun, 21 Jun 2009 17:12:15 -0700 (PDT) Received: by michelle.cdnetworks.co.kr (sSMTP sendmail emulation); Mon, 22 Jun 2009 09:17:05 +0900 From: Pyun YongHyeon Date: Mon, 22 Jun 2009 09:17:05 +0900 To: Wojciech Puchar Message-ID: <20090622001705.GA10712@michelle.cdnetworks.co.kr> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i Cc: freebsd-hackers@freebsd.org Subject: Re: is RTL8139 THAT bad? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: pyunyh@gmail.com List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Jun 2009 00:35:56 -0000 On Sun, Jun 21, 2009 at 05:14:29PM +0200, Wojciech Puchar wrote: > i have pentium 200 with that card. doing ftp from other machine, getting > 3.5MB/s (HDD can 10MB/s, DMA) having 45%-55% interrupt load. > > when sending it's not that bad. > > tried writing file to disk with cat /dev/zero >file, it's only 3% ints > with 10MB/s traffic. > > > Why it's THAT bad? > Because CPU always have to copy frames to/from the controller. These CPU cycles could have been used in other task to give more performance such as SSH encryption/decryption, checksum computation etc. > 3.5MB/s is less that 2500 packets/second. 50% at 200Mhz means 100000000 > cycles spend on interrupt service, which is 40000 CPU cycles per packet. > That depends on your application. It would be ok for normal desktop PCs with fast CPU but it wouldn't be acceptable on servers that have to do lots of other processing. If you have fxp(4) or txp(4) hardwares give them try first and see what's the difference with systat(1). Pushing the hardware to the limit by sending/receiving 64 bytes frames with netperf/iperf also would be good way to see how well the controller works under extreme loads.