Date: Mon, 24 Jul 2006 11:28:23 -0400 From: Jim Rees <rees@umich.edu> To: rick@snowhite.cis.uoguelph.ca Cc: fs@freebsd.org Subject: Re: freebsd4.11 patch for nfs over tcp Message-ID: <20060724152823.C32D81BB93@citi.umich.edu> In-Reply-To: <200607241456.KAA63411@snowhite.cis.uoguelph.ca> (rick@snowhite.cis.uoguelph.ca, Mon, 24 Jul 2006 10:56:50 EDT)
next in thread | previous in thread | raw e-mail | index | archive | help
Delayed acks when properly implemented should not cause a performance hit. The problem is that there are many buggy implementations. If you have to turn off delayed acks to get good nfs performance, then there is a bug in the tcp stack. See, for example, rfc 2525 page 40, "Stretch ACK violation." MacOS has this same problem. Having said that, the code is obviously wrong. It's trying to set NODELAY and failing. This has apparently been fixed, because 6.1 does not have this bug. I'm pretty sure 4.x is out of maintenance.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20060724152823.C32D81BB93>