Scott Chapman wrote:
>A potential issue is that some systems only have a single
>zIIP My personal belief is that given the amount of work
>that's zIIP eligible today, most systems should have at least
>2 zIIPs
I would add an important footnote. The current and prior model machine
generatio
>You really want Gary King or Dan Rosa to chime in, not me. I can rarely
keep the details straight. If they provide me with information to relay on
their behalf, I will be glad to.
Thanks, for the offer. How about forwarding my initial post. I had written the
points of interest to me, and I thi
>zIIP dispatching is the same as GP dispatching. ZIIPAWMT
has analogous parameters for GP (CCCAWMT) and zAAP (ZAAPAWMT).
Alternate wait management was created long before there were
specialty engines.
Thank, Jim, much appreciated.
Sorry, guys, for not reading the latest posts before writing mi
>I believe hyper dispatch is very different from zIIP dispatch. I stand by my
>assumption that GP dispatch is very different from zIIP dispatch, or why would
>there be the ZIIPAWMT parameter and have the comment about waking up after
>that interval to see if there is work. When non-zIIP work c
>the 'speed' (GHz) is always the same for all types
The 'speed' is not generally thought to be the cycle time. It is true that
the cycle time is the same across the models, but the effective speed is
not the same (such as MIPS or the MSU rating).
>the dispatcher code for ZIIP processing is not
ughkeepsie NY
"IBM Mainframe Discussion List" wrote on
06/09/2018 10:58:25 AM:
> From: "Christopher Y. Blaicher"
> To: IBM-MAIN@LISTSERV.UA.EDU
> Date: 06/09/2018 12:46 PM
> Subject: Re: Why are highly busy zIIPs worse than highly busy CPs?
> Sent by: "IBM
t;IBM Mainframe Discussion List" wrote on
06/09/2018 10:58:25 AM:
> From: "Christopher Y. Blaicher"
> To: IBM-MAIN@LISTSERV.UA.EDU
> Date: 06/09/2018 12:46 PM
> Subject: Re: Why are highly busy zIIPs worse than highly busy CPs?
> Sent by: "IBM Mainframe Discussi
ftware is now a part of Syncsort.
-Original Message-
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf
Of Ed Jaffe
Sent: Saturday, June 9, 2018 9:46 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: AW: Re: Why are highly busy zIIPs worse than highly busy CPs?
@LISTSERV.UA.EDU] On Behalf
Of Peter Hunkeler
Sent: Saturday, June 9, 2018 6:49 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: AW: Re: Why are highly busy zIIPs worse than highly busy CPs?
>First of all, the dispatcher code for ZIIP processing is not the same as the
>GP dispatcher.
Do you know this, or is i
On 6/9/2018 3:48 AM, Peter Hunkeler wrote:
First of all, the dispatcher code for ZIIP processing is not the same as the GP
dispatcher.
Do you know this, or is it just an assumption on your side? After all I read,
it still would't make sense to me.
The dispatcher is the dispatcher -- and it w
nframe Development
>> P: 201-930-8234 | M: 512-627-3803
>> E: cblaic...@syncsort.com
>>
>> Syncsort Incorporated
>> 2 Blue Hill Plaza #1563
>> Pearl River, NY 10965
>> www.syncsort.com
>>
>> Data quality leader Trillium Software is now a part of
>First of all, the dispatcher code for ZIIP processing is not the same as the
>GP dispatcher.
Do you know this, or is it just an assumption on your side? After all I read,
it still would't make sense to me.
If you think of the "need help" process for the zIIP to be special, isn't there
a sim
>Some of this dispatcher design by IBM could be based on the assumption that
>all the work is SRB and will be high priority work and of short duration.
This doesn't sound correct to me. Client SRBs (preemptive SRBs) were invented
to have some work done in another address space at client priorit
Syncsort.
>
>
> -Original Message-
> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On
Behalf Of Peter Hunkeler
> Sent: Friday, June 8, 2018 3:42 PM
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: AW: Re: Why are highly busy zIIPs worse than highl
>> Is it? If you think about Java, maybe. But when it comes to workload such as
>> DB2, Sort, Monitors, that have shifted more and more of its task towards
>> zIIPs, isn't this still the same workload?
>> --
>> Peter Hunkeler
>
>The zIIP-eligible criteria for choosing a subset of tasks to run on
3803
> E: cblaic...@syncsort.com
>
> Syncsort Incorporated
> 2 Blue Hill Plaza #1563
> Pearl River, NY 10965
> www.syncsort.com
>
> Data quality leader Trillium Software is now a part of Syncsort.
>
>
> -----Original Message-----
> From: IBM Mainframe Discussi
M-MAIN@LISTSERV.UA.EDU] On Behalf
Of Peter Hunkeler
Sent: Friday, June 8, 2018 3:42 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: AW: Re: Why are highly busy zIIPs worse than highly busy CPs?
>How prevalent are installations today where the CPs run at top speed, in other
>words at the same speed as
On 6/8/2018 2:06 PM, Joel C. Ewing wrote:
Would be curious if anyone has seen a more complete description about
how the sub-capacity CP enforcement works.
Every so often (I believe 4 usec on my z13s), there is something akin to
a timer interrupt in the chip that runs a millicode housekeeping
On 06/08/2018 02:50 AM, Parwez Hamid wrote:
> Re the comment:
>
> How prevalent are installations today where the CPs run at top speed, in
> other words at the same speed as zIIP engines? In other words, Is it that
> valid to assume equal speed processors? Clearly guidelines for lower zIIP
> u
>How prevalent are installations today where the CPs run at top speed, in other
>words at the same speed as zIIP engines?
I haven't got the faintest idea. We do, but that doesn't matter for this
discussion. I thought this is complex enough, so I take one part of complexity
out first: Differen
> the workload on the CP is totally different.
Is it? If you think about Java, maybe. But when it comes to workload such as
DB2, Sort, Monitors, that have shifted more and more of its task towards zIIPs,
isn't this still the same workload?
--
Peter Hunkeler
--
This seems to come up a lot.
I'm going to start by taking the opposite tack: you probably shouldn't run your
GCPs at 90-100% busy either. Busier CPUs are generally going to have more cache
contention which means the work is generally going to run "somewhat" less
efficiently (i.e. more CPU time
Re the comment:
How prevalent are installations today where the CPs run at top speed, in other
words at the same speed as zIIP engines? In other words, Is it that valid to
assume equal speed processors? Clearly guidelines for lower zIIP utilization
matter more when there is a difference, as o
On 06/07/2018 02:26 AM, Peter Hunkeler wrote:
> There are some statements around zIIP utilization which I read here and
> there. Statements like:
>
> - "You should not utilize one zIIP more than 30%, two zIIPs more than 60%..."
> - "A task may become delayed for up to 3.2 ms (actually ZIIPAWMT) be
>... however, we were warned that 'some customers' were experiencing serious
>performance problems when zIIP eligible work spilled over to general CPs.
Yeah, that is what I read and hear also, and I have no reason not to believe
it. In fact, I suspect we've just been bitten by zIIP overload. How
channel: https://www.youtube.com/channel/UCu_65HaYgksbF6Q8SQ4oOvA
From: Jesse 1 Robinson
To: IBM-MAIN@LISTSERV.UA.EDU
Date: 07/06/2018 17:54
Subject: Re: Why are highly busy zIIPs worse than highly busy CPs?
Sent by:IBM Mainframe Discussion List
We've had zIIPs for years. We monit
3573?mt=2
Youtube channel: https://www.youtube.com/channel/UCu_65HaYgksbF6Q8SQ4oOvA
From: Peter Hunkeler
To: IBM-MAIN@LISTSERV.UA.EDU
Date: 07/06/2018 17:14
Subject: AW: Re: Why are highly busy zIIPs worse than highly busy
CPs?
Sent by:IBM Mainframe Discussion List
e
626-543-6132 Office ⇐=== NEW
robin...@sce.com
-Original Message-
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf
Of Peter Hunkeler
Sent: Thursday, June 07, 2018 9:21 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: (External):AW: Re: Why are highly busy zII
>Isn't "fall back to the CP" because one would typically want one's work to
run *somewhere* even if a zIIP were not available but perhaps a CP was?
If you meant no zIIPs are available to the LPAR (not configured or the CEC does
not have some), then there is no fall-back. Work units get queue
>Scheduling an SRB isn't cheap. I don't know whether that's why, but for
>whatever reason, IBM has built this "fall back to the CP" mechanism.
What falls back is still SRBs. The scheduling overhead has already been done
before.
--
Peter Hunkeler
---
>Once the delay is long enough, the CP does the work. They cost about 10X the
>price of zIIPs.
I understand the potential impact on the software bill zIIP-on-CP might have.
That is not the point I want to get a better understanding. I'm interested in
the technical aspects, only.
IMHO, from
if none of the "wanna
get away" seats are available, I will buy a full-fare seat.
Charles
-Original Message-
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On
Behalf Of Phil Smith
Sent: Thursday, June 7, 2018 8:38 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject:
Peter Hunkeler wrote, in part:
>There are some statements around zIIP utilization which I read here and there.
>Statements like:
>- "You should not utilize one zIIP more than 30%, two zIIPs more than 60%..."
>- "A task may become delayed for up to 3.2 ms (actually ZIIPAWMT) before the
>busy zIIP
Once the delay is long enough, the CP does the work. They cost about
10X the price of zIIPs.
On Thu, Jun 7, 2018 at 4:36 AM Elardus Engelbrecht
wrote:
>
> Peter Hunkeler wrote:
>
> >- "You should not utilize one zIIP more than 30%, two zIIPs more than 60%..."
>
> Who said it? And why 30%? Just cu
Peter Hunkeler wrote:
>- "You should not utilize one zIIP more than 30%, two zIIPs more than 60%..."
Who said it? And why 30%? Just curious.
My one zIIP (for about 8 LPARs on one machine) is usually anything from 5% to
40-50% in workdays, while the zIIP management overhead is usually from 0.5%
There are some statements around zIIP utilization which I read here and there.
Statements like:
- "You should not utilize one zIIP more than 30%, two zIIPs more than 60%..."
- "A task may become delayed for up to 3.2 ms (actually ZIIPAWMT) before the
busy zIIP asks for help from a CP".
For th
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