[comp.sys.sun] IPC semaphores: anyone used them?

metcalf@masala.lcs.mit.edu (Chris Metcalf) (05/24/91)

I'm trying to use the SysV semaphore stuff (semget, semctl, semop) on a
variety of Sun 4s running SunOS 4.1.  Certain calls to semop() pretty
nearly crash the machine (in particular, a call with two sembufs with a
positive and a negative sem_op will do this).  The result is that the
window system freezes and no new processes are forked:  a remote xload
will keep going, and inetd will hand out sockets, but you can't do
anything more without a reboot.

Has anyone used the semaphore stuff, and (possibly) seen this?  Is it a
bug in 4.1?

Thanks very much!

Chris Metcalf, MIT Laboratory for Computer Science
metcalf@masala.lcs.mit.edu // (617) 253-7766

aldo@fernwood.mpk.ca.us (Aldo Castillo) (06/05/91)

In article <2903@brchh104.bnr.ca> metcalf@masala.lcs.mit.edu (Chris Metcalf) writes:

{gripes deleted}

>Has anyone used the semaphore stuff, and (possibly) seen this?  Is it a
>bug in 4.1?
>

The GENERIC_SMALL kernel does NOT support System V IPC calls.  So I wonder if
you running the GENERIC_SMALL kernel or another kernel with the same missing
feature..

If that is the case, you have to rebuild your kernel, making sure that
/sys/sun4c/conf/<kernel name>'s 3 lines starting with "options IPC" have
not been commented out.

	Aldo Castillo
	Staff Software Engineer