-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hallo, Philip,
management summary: It does look like svnserve is innocent and openvz's write call is to blame after all! Firstly, I have now been able to move this entire affair off my internet "production" server. The bug is reproducible locally, on my "home" machine, with a plain Debian sid openvz guest (hosted by a plain Debian lenny host). Even better: svn client and svn server on that same openvz guest machine reproduce this bug! That is, a simple "svn co svn://localhost bug" does the trick! I also tried the other direction: A big "svn ci" to svn://localhost . This also hangs, but this time on the svn (client) side. > Somebody (you probably) needs to debug it. Ooouch... Have not touched gdb for some 10 years now... But, if debug we must, debug we must. I thought. So I dutifully grabbed the code from http://svn.apache.org/repos/asf/subversion/trunk and compiled that, and could reproduce the bug with that as well. Just short of digging up the gdb documentation, I did one final "strace -f -ff -o ...". Interestingly, while svnserve was burning CPU cycles like crazy, the trace log of that particular process did not grow! The last syscall which strace had logged was a write call. Which had not yet written its return value. This is what it looked like: write(4, "7\310 lots of data skipped here"..., 99321 So it seems svnserve is hanging, burning CPU cycles, FROM INSIDE A WRITE SYSTEM CALL! Which got interrupted when I finally killed the server. Now there was a return value, indicating a partial write: write(4, "7\310 lots of data skipped here"..., 99321) = 44701 - --- SIGTERM (Terminated) @ 0 (0) --- > As I understand it OpenVZ involves a custom kernel with it's own network drivers, > perhaps the write syscall is doing something unexpected. I now think you are right on target with that one! It does look like we need to blame openvz or the Linux kernel, after all. I'll try to cobble together a few-line C server and see whether that reproduces the bug. I'll let you know whether the result of that experiment matches what we now think is going on. So, for now, it looks like no svn bug after all. Regards, Andreas - -- Dr. Andreas Krüger, Berater, DV-RATIO NORDWEST GmbH andreas.krue...@dv-ratio.com GPG/PGP Fingerprint 8063 4A9B 362D 4220 A546 14C1 EA19 AADC FD44 5EB7 DV-RATIO NORDWEST GmbH Tel: +49 (0)211 / 577 996-0 Fax: +49 (0)211 / 577 996-26 http://www.dv-ratio.com <http://www.dv-ratio.com> Sitz der Gesellschaft Habsburgerstraße 12, 40547 Düsseldorf Registergericht Düsseldorf HRB 34330 USt-IdNr.: DE811321837 Steuer-Nr.: 809/44031 Geschäftsführung: Günter Gerstmann Prokura: Trudbert Vetter, Uwe Wolfram DV-RATIO - "Kompetenz und Zuverlässigkeit seit 1980" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEUEARECAAYFAkuNDKUACgkQ6hmq3P1EXre2WgCXb56x2wO69Yv67TFZDdMYwuf9 6QCglgz9erNa/uG/2ScjCGsAbIRcsEU= =Fzgm -----END PGP SIGNATURE-----
