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

"DIE" ??

Umm  Device Interrupt Handler ???  ((somewhat ) educated guess)

On Thu, May 20, 2010 at 1:01 PM, PeterH <[email protected]> wrote:

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>
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> On May 20, 2010, at 9:25 AM, Mike Stramba wrote:
>
> > ..Except for the the "spin" messages, it was spewing, which I had
> > no idea what they meant ;)
> >
>
> Certain "locks" within MVS are so-called "suspend" locks (LOCAL LOCK,
> e.g.) whereas other locks within MVS are so-called "spin" locks
> (CHANNEL LOCK, e.g.).
>
> There is only one "spin" lock within MVS which is not part of the
> LOCKing system, and that is the disabled lock within IEWFETCH, which
> is utilized to ensure that at least 240 bytes of the CONTROL/RLD
> record has been read, when FETCH is reading such records, as the
> relocation function which FETCH performs is done in a DIE, in
> response to a PCI interrupt issued by the channel when the READ
> CONTROL/RLD CCW was fetched by the channel.
>
> The DIE "spins" on a byte within the CONTROL/RLD record, and when
> that byte changes, the DIE knows that the channel has actually read
> the CONTROL/RLD record, and it is safe for the data within that
> record to be processed.
>
>  
>