spl5() call in kern_exit.c (4.2BSD)

[Jim Moore]

Can any wizards out there explain the call to spl5() in the
4.2 exit code? The comment just says something like:

	(void) spl5();		/* hack for mem alloc race XXX */

I am trying to cut down on the amount of time that the kernel
stays at high interrupt priority, and this code maintains spl5
all the way into swtch(). Any one know what race condition this
interlock avoids?

As usual, I'll summarize upon request.

Thanks,
Jim Moore
NBI, Boulder Colorado
[ucbvax|hao|amd]!nbires!jmoore