Re: intermittent hangs with threads (clone() bug?/linuxthreads bug?)

[Wolfram Gloger]

Hi,

> I am experiencing intermittent hangs running LinuxThreads programs from a 
> shell script.  This happens with any combination of stock RH 7.1 SMP kernel 
> (2.4.2) or my own 2.4.5 kernel and stock RH 7.1 libc (2.2.2), redhat rawhide 
> libc (2.2.3) and my own 2.2.3 libc.
> 
> If I run, for example, linuxthreads/Examples/ex1 (one thread prints 'a', one 
> prints 'b') it will run fine.  If I run it from a shell script (bash or ksh) 
> with 
>    exec ex1
> it almost always hangs.
...
> (gdb) where
> #0  0x40067ff5 in __sigsuspend (set=0xbffff2e8)
>     at ../sysdeps/unix/sysv/linux/sigsuspend.c:45
> #1  0x4002d25f in __pthread_wait_for_restart_signal (self=0x40036300)
>     at pthread.c:958
> #2  0x4002cbc4 in __pthread_create_2_1 (thread=0xbffff454, attr=0x0, 
>     start_routine=0x8048580 <process>, arg=0x804871d) at restart.h:34
> #3  0x080485e7 in main () at ex1.c:29
> #4  0x400565e7 in __libc_start_main (main=0x80485cc <main>, argc=1, 
>     ubp_av=0xbffff4c4, init=0x80483d0 <_init>, fini=0x80486e0 <_fini>, 
>     rtld_fini=0x4000e154 <_dl_fini>, stack_end=0xbffff4bc)
>     at ../sysdeps/generic/libc-start.c:129

Your report is very interesting to me, because I'm currently
investigating a problem with fork() and malloc() where I see exactly
the same symptoms.  So you say you can reproduce it with just 2 CPUs
(I only have access to a 2 CPU machine) and the unchanged `ex1' code?
I will try that tonight.

Thanks,
Wolfram.