Does SIGXCPU work under AIX 3.1?

[Scott Holt]

In article <6893 at mace.cc.purdue.edu> abe at mace.cc.purdue.edu (Vic Abell) writes:
>The attached test program works under BSD 4.3-Tahoe, Ultrix 2.2, SunOS
>4.0.3, NeXTOS 1.0 and DYNIX 3.0.12.   It doesn't work under AIX 3.1
>(3003).  What else do I need do to limit CPU time?
>
>Csh's "limit cputime nnn" command doesn't seem to work, either.
>
>Vic Abell <abe at mace.cc.purdue.edu>

In short - no. SIGXCPU does not work.

Despite documentation to the contrary (see info pages for set/getrlimit),
A SIGXCPU is not sent to a process upon reaching its soft CPU time limit.
Nothing is sent at all - there is no CPU time limit under AIX 3.

I reported this problem to IBM and their response was that it was a 
documentation error. They refered me to the info entry for the Limits file -
which states that the CPU time limit in the file is not used. Their fix - 
change the documentation to setrlimit.

In all fairness to the software defects group - they were actually quite
helpfull...but what can they do other than collect the details and refer
the problem to the developers. They suggested the route I am going to take,
put in a request for a design change through our local reps. Perhaps you
should do the same.

For us, the ability to have a CPU time limit is crucial - we plan to implement
a processor farm of sorts managed by a batch management system such as NQS.
CPU time limits (as well as memory limits and others that AIX does support)
are vitally important to such a system - especially when batch queue priorities
and job scheduling are to be based on resource demands. If we can't have
a reasonable method to enforce all resource limits, then we cannot use
the machine for this project.

- Scott
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