From mboxrd@z Thu Jan 1 00:00:00 1970 From: bert hubert Subject: Re: [RESEND] tuning linux for high network performance? Date: Wed, 23 Oct 2002 19:01:02 +0200 Sender: netdev-bounce@oss.sgi.com Message-ID: <20021023170102.GA5302@outpost.ds9a.nl> References: <200210231218.18733.roy@karlsbakk.net> <20021023130101.GA646@outpost.ds9a.nl> <1035379308.5950.3.camel@rth.ninka.net> <200210231542.48673.roy@karlsbakk.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "David S. Miller" , netdev@oss.sgi.com, Kernel mailing list Return-path: To: Roy Sigurd Karlsbakk Content-Disposition: inline In-Reply-To: <200210231542.48673.roy@karlsbakk.net> Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org On Wed, Oct 23, 2002 at 03:42:48PM +0200, Roy Sigurd Karlsbakk wrote: > > The e1000 can very well do hardware checksumming on transmit. > > > > The missing piece of the puzzle is that his application is not > > using sendfile(), without which no transmit checksum offload > > can take place. > > As far as I've understood, sendfile() won't do much good with large files. Is > this right? I still refuse to believe that a 1.8GHz Pentium4 can only checksum 250megabits/second. MD Raid5 does better and they probably don't use a checksum as braindead as that used by TCP. If the checksumming is not the problem, the copying is, which would be a weakness of your hardware. The function profiled does both the copying and the checksumming. But 250megabits/second also seems low. Dave? Regards, bert -- http://www.PowerDNS.com Versatile DNS Software & Services http://lartc.org Linux Advanced Routing & Traffic Control HOWTO