Re: fix TCP roundtrip time update code

David Mosberger
2003-06-04T04:22:42Z

>>>>> On Tue, 03 Jun 2003 20:23:20 -0700 (PDT), "David S. Miller" <davem@redhat.com> said:

DaveM> From: Nivedita Singhvi <niv@us.ibm.com> Date: Tue, 03 Jun
DaveM> 2003 19:01:25 -0700
DaveM> But, FYI, DaveM and Alexey, we tried reproducing the
DaveM> stalls we (Dave Hansen, Troy Wilson) had seen during
DaveM> SpecWeb99 runs and couldn't reproduce them on 2.5.69. (Same
DaveM> config, etc). So its possible our hang/stalls were some other
DaveM> issue that got silently fixed (or more likely, possibly the
DaveM> same thing but other changes minimized us running into the
DaveM> problem).

DaveM> I think this means nothing, and that you can infer nothing
DaveM> from such results.

DaveM> My understanding is that the problem case triggers only when
DaveM> a timeout based retransmit occurs. On LAN this tends to be
DaveM> extremely rare. Although under enough traffic load it can
DaveM> occur.

DaveM> So if your old SpecWEB99 lab tended more to trigger timeout
DaveM> based retransmits on LAN, and your new test network does not,
DaveM> then your new test network will tend to not reproduce the bug
DaveM> regardless of whether the bug is present in the kernel or not
DaveM> :-)

Is this where I get to plug httperf? It triggered the bug reliably in
less than 10 secs. ;-)

--david