From mboxrd@z Thu Jan 1 00:00:00 1970 From: bert hubert Date: Tue, 01 Jan 2002 18:58:29 +0000 Subject: Re: [LARTC] RED problem ! Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lartc@vger.kernel.org On Tue, Jan 01, 2002 at 10:33:06PM +0530, Arindam Haldar wrote: > hi all, > > while trying red inplace of sfq/pfifo i go the follwing error > > tc qdisc add dev eth0 parent 1:470 red max 12288 min 6100 limit 12288 > avpkt 1514 burst 2 This returns -1: int tc_red_eval_ewma(unsigned qmin, unsigned burst, unsigned avpkt) { int wlog = 1; double W = 0.5; double a = (double)burst + 1 - (double)qmin/avpkt; if (a < 1.0) return -1; for (wlog=1; wlog<32; wlog++, W /= 2) { if (a <= (1 - pow(1-W, burst))/W) return wlog; } return -1; } You can use this to calculate what is wrong. Either burst+1-qmin/avpkt is smaller than 1, or a is too high to be matched by a time constant. Regards, bert -- http://www.PowerDNS.com Versatile DNS Software & Services http://www.tk the dot in .tk Netherlabs BV / Rent-a-Nerd.nl - Nerd Available - Linux Advanced Routing & Traffic Control: http://ds9a.nl/lartc _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://ds9a.nl/lartc/