Is MAXUPRC broken in SunOS 4.0.3 ?

[Paul Falstad]

chogan at maths.tcd.ie (Christine Hogan) wrote:
>On our SS1 running SunOS 4.0.3 there is no limit on the number
>of processes a user can run, despite MAXUPRC being defined to be
>25 in our sys/param.h.  Has anyone else noticed this ?

I don't think the value in sys/param.h makes any difference.  In
SunOS 4.1.1, at least, the limiting factor on user processes is the
variable maxuprc, which for some strange reason is set to 5+16*MAXUSERS.
So there IS a limit.  The load average would have peaked at ~1000,
if it's any consolation.  :-)

MAXUPRC is #defined in /usr/kvm/sys/conf.common/param.c.  Hopefully you
have something similar in 4.0.3.

We had similar problems at our site until the sysadmin reconfigured the
kernel with this set to a sane value (NOT dependent on MAXUSERS).

>Is this fixed in later releases (we may be upgrading soon) ?  Is

No.

>there a patch available to fix this ?  We do not have the sources. 

Well, if nothing else, you could always adb the kernel.  :-)

# adb -w /vmunix
_maxuprc?X
_maxuprc:
_maxuprc:   403  <- a tad too high (that's 1027 decimal)
.?W 19
_maxuprc:
_maxuprc:   0x403    =  0x19
^D
# ...

--
Paul Falstad, pfalstad at phoenix.princeton.edu | 10 PRINT "PRINCETON CS"
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Princeton University would like to apologize to everyone for this article.