Re: nscd and recent Linux kernels

[Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>]

> I have found a big problem with nscd on Linux 2.0.34 (not 2.0.33 or
> earlier) and late Linux 2.1.9x. With this kernels, it is no problem to 
> get nscd to hang. You could reproduce the problem with untarring the
> current glibc snapshot in 2 xterm windows at the same time. nscd will
> hang in the select call in connections.c/get_request. It will not
> answer to passwd and group querys, but nscd -g and nscd -K works. I'm
> not able to find the problem or to find a workaround for it. Does
> anybody know, which changes where made in the kernel, that could
> causes the problems ?

It was attempted to make select() was (more) thread-safe -- see the

--- v2.0.33/linux/fs/select.c   Mon Dec 30 05:57:02 1996
+++ linux/fs/select.c   Wed Jun  3 15:17:49 1998

hunk in patch-2.0.34.  It looks like you could try to simply back out
this change and see whether it makes the difference.  It would be a
pity if a thread-showstopping bug crept into a stable kernel...

Regards,
Wolfram.