bad NFS/UDP performance
danny at cs.huji.ac.il
Mon Sep 29 07:56:34 UTC 2008
> > On Fri, 26 Sep 2008, Danny Braniss wrote:
> > > after more testing, it seems it's related to changes made between Aug 4 and
> > > Aug 29 ie, a kernel built on Aug 4 works fine, Aug 29 is slow. I'l now try
> > > and close the gap.
> > I think this is the best way forward -- skimming August changes, there are a
> > number of candidate commits, including retuning of UDP hashes by mav, my
> > rwlock changes, changes to mbuf chain handling, etc.
> it more difficult than I expected.
> for one, the kernel date was missleading, the actual source update is the key, so
> the window of changes is now 28/July to 19/August. I have the diffs, but nothing
> yet seems relevant.
> on the other hand, I tried NFS/TCP, and there things seem ok, ie the 'good' and the 'bad'
> give the same throughput, which seem to point to UDP changes ...
Grr, there goes binary search theory out of the window,
So far I have managed to pinpoint the day that the changes affect the
18/08/08 00:00:00 19/08/08 00:00:00
(I assume cvs's date is GMT).
now would be a good time for some help, specially how to undo changes, my
knowledge of csup/cvs are close to zero.
More information about the freebsd-stable