From owner-freebsd-hackers Sat Mar 20 23:31: 9 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [209.157.86.2]) by hub.freebsd.org (Postfix) with ESMTP id 9A1B3150C2 for ; Sat, 20 Mar 1999 23:31:08 -0800 (PST) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.3/8.9.1) id XAA09427; Sat, 20 Mar 1999 23:30:42 -0800 (PST) (envelope-from dillon) Date: Sat, 20 Mar 1999 23:30:42 -0800 (PST) From: Matthew Dillon Message-Id: <199903210730.XAA09427@apollo.backplane.com> To: Bill Paul Cc: julian@whistle.com (Julian Elischer), hackers@freebsd.org Subject: Re: Gigabit ethernet revisited References: <199903210718.CAA08119@skynet.ctr.columbia.edu> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :So, how long after the process is marked runable does the scheduler :actually transfer control to the process so that it can handle the :received data? Can the process be prevented from running if there are :too many interrupts from the NIC? Is there some way to make the scheduler :run the process more often (I tried using nice -20 on the receving :instance of ttcp; that didn't seem to make a difference)? Has anybody :else actually tried to receive data at 600 to 800Mbps speeds on FreeBSD :and done it reliably? (Note: I mean actually transmitting UDP packets at, :say 80MB/sec and actually receiving _all_ of the transmitted packets on :the other side, in the application, at the same speed. No fudging.) :Transmit speed doesn't seem to be an issue here, but somehow I get the :feeling that the kernel is sabotaging itself on receive. : :-Bill You need to do the test I suggested sinking the packets into the bit bucket with ipfw. You also need to do a cpu loading test - graph the cpu utilization as displayed by vmstat or 'systat -vm 1' verses the packet load, both going into the bit bucket, or being read by a process. If there is any cpu available, runnable processes will run no matter what the cpu load. -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message