This bug is Debian specific: The endless looping inside the kernel
system call is not present in a current openvz upstream kernel.
I'm refering to Debian bug 571457 which, according to Maximilian, is
probably the same as bug 542633 .
The details:
I had filed an upstream bug report
http://bugzilla.openvz.org/show_bug.cgi?id=1443 . In that bug's
discussion, Pavel Emelyanov asked me to verify whether the bug was
present in their git kernel.
So I grabbed their kernel source
git clone git://git.openvz.org/pub/linux-2.6.26-openvz openvz-git-kernel
For configuration, I used Debian's linux-image-2.6.26-2-openvz-686,
Version 2.6.26-21lenny4 as my baseline, via
cp /boot/config-2.6.26-2-openvz-686 .config
I compiled the sources via
make-kpkg --initrd kernel_image
(which didn't at first work. The directory permissions of /usr/src had
infected my git directory with g+s, and, after a long time of churning,
make-kpkg decided it didn't like that.)
The good news: After booting into that kernel, my example runs fine as
expected! No more endless looping and CPU cycle eating.
Instead, a mere 20 milliseconds user time consumed by the server. The
Perl client is through in 1.5 seconds real runtime.
For comparison, directly on the host machine (a somewhat dated box), the
server's user stays the same, the client's real is about 0.1 seconds
faster.
After two runs on a freshly started openvz client, I get 511 tcpsndbuf
fail counts
grep tcpsnd /proc/user_beancounters
tcpsndbuf 0 70400 70000 150000 511
which was to be expected.
Regards,
Andreas
--
Dr. Andreas Krüger, Berater, DV-RATIO NORDWEST GmbH
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