Re: NUMCPU >1 = IEE331A EXCESSIVE DISABLED SPIN LOOP DETECTED

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>  
>
> Just for fun, I changed the NUMCPU to 2, when I IPL'd Turnkey MVS
> (actually t33su),
> the console displayed :
>
> IEE331A EXCESSIVE DISABLED SPIN LOOP DETECTED
> WAITING FOR LOCK RELEASE
> REPLY U TO CONTINUE SPIN
> IEF677I WARNING MESSAGE(S) FOR JOB JES2 ISSUED
>
> - $HASP493 JES2 QUICK-START IS IN PROGRESS
>
> - $HASP412 MAXIMUM OF 1 READER(S) EXCEEDED
> IEE041I THE SYSTEM LOG IS NOW ACTIVE
>
> I *thought* MVS would just ignore the second CPU, but apparently it
> doesn't ... but it doesn't seem to utilize it "properly" either ?
>
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Unless the I/O load exceeds certain user-defined levels, all but one CPU 
runs disabled for I/O interrupts. SPIN locks are used to serialize 
activities between multiple CPU's in the CEC. What you've seen is not at 
all unusual in a multi-processor CEC.

Typically, any processor in the CEC may initiate I/O operations but only 
one fields the resulting interrupts. Helps to control I/O delays to 
processing by limiting interrupts.

Rick