On Wed, Apr 20, 2005 at 04:38:42PM +0200, Marc Olzheim wrote: > On Wed, Apr 20, 2005 at 10:24:48AM -0400, Brian Fundakowski Feldman wrote: > > > It does and it seems to work. The NFS performance drops considerably > > > though, from 8/9 MByte/s to 3/4 on sequential reads for instance. > > > > > > kern/79208 is fixed by this indeed, in that I get short writes (in case > > > of my test server at 1802240+ bytes, so './writev 2 foo' fails... > > > > Performance drops in what cases? > > Hmm, seems only to happen in large sequential reads... It might just be > the FreeBSD 4.6 NFS server that is the problem though. I've had more NFS > troubles with it. Reads should be totally unaffected... > Btw.: I'm not sure write(),writev() and pwrite() are allowed to do short > writes on regular files... ? Our manpage is incorrect; POSIX states that they are (see earlier e-mail). There really is no alternative -- we simply can't build an NFS transaction larger than our buffer cache can accomodate. Note that short wries won't happen for normal buffer sizes, only excessively large ones. I really don't believe that writev() is meant to be used so that you can write gigantic data structures in a single transaction... -- Brian Fundakowski Feldman \'[ FreeBSD ]''''''''''\ <> green_at_FreeBSD.org \ The Power to Serve! \ Opinions expressed are my own. \,,,,,,,,,,,,,,,,,,,,,,\Received on Wed Apr 20 2005 - 13:22:27 UTC
This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:38:32 UTC