[Simh] No recognizable idle loop
Galen Tackett
gtackett at yahoo.com
Tue Apr 4 17:32:24 EDT 2006
Mark,
Your modification to allow idle loop detection sounds great. I hope Bob
is reading this too as I certainly cast my humble vote in favor.
Galen
On Apr 4, 2006, at 4:00 AM, simh-request at trailing-edge.com wrote:
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> Today's Topics:
>
> 1. No recognizable idle loop (bsupnik at comcast.net)
> 2. Re: No recognizable idle loop (Norman Lastovica)
> 3. Re: No recognizable idle loop (Brian Knittel)
> 4. Re: No recognizable idle loop (Villy Madsen)
> 5. Loosing the first terminal character (Villy Madsen)
> 6. Ethernet Connectivity (Villy Madsen)
> 7. SIMH emulator running on Windows Mobile 2003? (Jay Mumper)
> 8. Re: SIMH emulator running on Windows Mobile 2003? (Zane H. Healy)
> 9. Re: SIMH emulator running on Windows Mobile 2003? (Tim Pinkawa)
> 10. Re: No recognizable idle loop (Mark Pizzolato)
>
> From: bsupnik at comcast.net
> Date: April 3, 2006 1:08:36 PM EDT
> To: simh at trailing-edge.com
> Subject: [Simh] No recognizable idle loop
>
>
> I've seen this question so many times, here's the definitive answer:
> there is no idle job or simple idle loop in VMS. Instead, VMS loops
> in the scheduler (at IPL 3) waiting for interrupts or for something to
> appear on a scheduler queue as a result of a higher priority
> interrupt. Here is the code from VMS 7.2:
>
> 61$:
> JSB G^EXE$PROC_IDLE ;SEE IF WE HAVE CPU SPECIFIC IDLE LOOP
> BLBS R0,61$ ;NO - GO TO STANDARD LOOP
> BBC #CPB$V_RUN,CPU$L_CAPABILITY(R3),70$ ; RUN CAPABILITY PRESENT?
> BBS R1,G^SCH$GL_IDLE_CPUS,60$ ;LOOP UNTIL WE AREN'T IDLE
> BRB 65$
> 61$:
> BBC #CPB$V_RUN,CPU$L_CAPABILITY(R3),80$ ; RUN CAPABILITY PRESENT?
> TSTL G^SCH$GL_TBSH ; Class scheduler present?
> BEQL 64$ ; No, see if still idle
> JSB G^SCH$CLASS_IDLE ; Yes, see if TBS job runnable
> 64$:
> BBS R1,G^SCH$GL_IDLE_CPUS,61$ ;LOOP UNTIL WE AREN'T IDLE
>
> This varies from release to release as well.
>
> /Bob Supnik
>
>>
>> Message: 5
>> Date: Mon, 03 Apr 2006 08:55:43 -0600
>> From: Villy Madsen <Villy.Madsen at shaw.ca>
>> Subject: [Simh] VMS Idle loop
>> To: simh at trailing-edge.com
>> Message-ID: <69d691969d7ad0.69d7ad069d6919 at shaw.ca>
>> Content-Type: text/plain; charset=us-ascii
>>
>> Does anyone have a clue what the vax/vms idle loop looks like..
>>
>> at one point in time I had been told it was just a
>> BRB pointing to itself
>>
>> (so would that be brb 0 or brb -1 - it's been too many years and and
>> I can't
>> remember).
>>
>>
>> In case you are wondering, I am wondering if it would be possible to
>> build a
>> throttle into the simulator so that it doesn' run wide open all of
>> the time...
>>
>> Villy
>>
>>
>>
>> ------------------------------
>>
>> _______________________________________________
>> Simh mailing list
>> Simh at trailing-edge.com
>> http://mailman.trailing-edge.com/mailman/listinfo/simh
>>
>>
>> End of Simh Digest, Vol 29, Issue 2
>> ***********************************
>
>
>
>
>
>
> From: "Norman Lastovica" <norman.lastovica at oracle.com>
> Date: April 3, 2006 1:26:20 PM EDT
> To: <bsupnik at comcast.net>, <simh at trailing-edge.com>
> Subject: Re: [Simh] No recognizable idle loop
>
>
> SRI (for charon-vax) includes a utility that appears
> to detect the idle loop in the emulated system and
> somehow notifies the emulator of this and presumably
> then the emulator is able to 'throttle back'. check
> out:
>
> www.emulatorsinternational.com/downloads/cvax3100.pdf
>
>> -----Original Message-----
>> From: simh-bounces at trailing-edge.com
>> [mailto:simh-bounces at trailing-edge.com]On Behalf Of
>> bsupnik at comcast.net
>> Sent: Monday, April 03, 2006 11:09 AM
>> To: simh at trailing-edge.com
>> Subject: [Simh] No recognizable idle loop
>>
>>
>> I've seen this question so many times, here's the definitive answer:
>> there is no idle job or simple idle loop in VMS. Instead, VMS loops
>> in the scheduler (at IPL 3) waiting for interrupts or for something to
>> appear on a scheduler queue as a result of a higher priority
>> interrupt. Here is the code from VMS 7.2:
>>
>> 61$:
>> JSB G^EXE$PROC_IDLE ;SEE IF WE HAVE CPU SPECIFIC IDLE LOOP
>> BLBS R0,61$ ;NO - GO TO STANDARD LOOP
>> BBC #CPB$V_RUN,CPU$L_CAPABILITY(R3),70$ ; RUN CAPABILITY PRESENT?
>> BBS R1,G^SCH$GL_IDLE_CPUS,60$ ;LOOP UNTIL WE AREN'T IDLE
>> BRB 65$
>> 61$:
>> BBC #CPB$V_RUN,CPU$L_CAPABILITY(R3),80$ ; RUN CAPABILITY PRESENT?
>> TSTL G^SCH$GL_TBSH ; Class scheduler present?
>> BEQL 64$ ; No, see if still idle
>> JSB G^SCH$CLASS_IDLE ; Yes, see if TBS job runnable
>> 64$:
>> BBS R1,G^SCH$GL_IDLE_CPUS,61$ ;LOOP UNTIL WE AREN'T IDLE
>>
>> This varies from release to release as well.
>>
>> /Bob Supnik
>>
>>>
>>> Message: 5
>>> Date: Mon, 03 Apr 2006 08:55:43 -0600
>>> From: Villy Madsen <Villy.Madsen at shaw.ca>
>>> Subject: [Simh] VMS Idle loop
>>> To: simh at trailing-edge.com
>>> Message-ID: <69d691969d7ad0.69d7ad069d6919 at shaw.ca>
>>> Content-Type: text/plain; charset=us-ascii
>>>
>>> Does anyone have a clue what the vax/vms idle loop looks like..
>>>
>>> at one point in time I had been told it was just a
>>> BRB pointing to itself
>>>
>>> (so would that be brb 0 or brb -1 - it's been too many years and and
>>> I can't
>>> remember).
>>>
>>>
>>> In case you are wondering, I am wondering if it would be possible to
>>> build a
>>> throttle into the simulator so that it doesn' run wide open all of
>> the time...
>>>
>>> Villy
>>>
>>>
>>>
>>> ------------------------------
>>>
>>> _______________________________________________
>>> Simh mailing list
>>> Simh at trailing-edge.com
>>> http://mailman.trailing-edge.com/mailman/listinfo/simh
>>>
>>>
>>> End of Simh Digest, Vol 29, Issue 2
>>> ***********************************
>>
>>
>> _______________________________________________
>> Simh mailing list
>> Simh at trailing-edge.com
>> http://mailman.trailing-edge.com/mailman/listinfo/simh
>>
>
>
>
>
>
> From: "Brian Knittel" <brian at quarterbyte.com>
> Date: April 3, 2006 2:09:34 PM EDT
> To: simh at trailing-edge.com
> Subject: Re: [Simh] No recognizable idle loop
>
>
> Their idle detection scheme works within VMS,
> and I'd be willing to bet that their "idle.exe"
> utility communicates directly with the emulator
> via some sort of special trap instruction.
> In a sense, they're modifying the operating system
> and letting it know that it's running on an emulator.
>
> When you break the fourth wall, so to speak, just
> about anything is possible.
>
> Brian
>
> On 3 Apr 2006 at 11:26, Norman Lastovica wrote:
>
>> SRI (for charon-vax) includes a utility that appears
>> to detect the idle loop in the emulated system and
>> somehow notifies the emulator of this and presumably
>> then the emulator is able to 'throttle back'. check
>> out:
>>
>> www.emulatorsinternational.com/downloads/cvax3100.pdf
>
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> _| _| _| Brian Knittel
> _| _| _| Quarterbyte Systems, Inc.
> _| _| _| Tel: 1-510-559-7930
> _| _| _| Fax: 1-510-525-6889
> _| _| _| Email: brian at quarterbyte.com
> _| _| _| http://www.quarterbyte.com
>
>
>
>
>
> From: Villy Madsen <Villy.Madsen at shaw.ca>
> Date: April 3, 2006 2:17:40 PM EDT
> To: Brian Knittel <brian at quarterbyte.com>
> Cc: simh at trailing-edge.com
> Subject: Re: [Simh] No recognizable idle loop
>
>
> So how about a process (the idle utility) that runs at extremely low
> priority and increments an IO register (defined within SIMH) in a very
> tight loop. SimH periodically (what ever that means)checks the value,
> resets it and sets sleep parameters accordingly.
>
> The higher the count, the longer the sleep. If the "idle utility" is
> not running under VMS, the value never gets incremented, and simh
> assumes that the VAX is running under full load....
>
> Villy
>
>
>
>
>
>
> From: Villy Madsen <Villy.Madsen at shaw.ca>
> Date: April 3, 2006 9:18:50 PM EDT
> To: "simh at trailing-edge.com" <simh at trailing-edge.com>
> Subject: [Simh] Loosing the first terminal character
> Reply-To: "Villy.Madsen at shaw.ca" <Villy.Madsen at shaw.ca>
>
>
> Thanks for all of your input...
>
> after installing a second interface, and lots of palying around and
> beating my head ......
>
> it appears that the problem is the terminal emulator that I am running
>
> a demo copy of MochaTerm.
>
> My experience in the past with Mochasoft (I've used their TN5250
> product for years)
> is that their demo products usually only have a mildly irritating
> advert that shows up on the top banner
> area ( We bought a license for the TN5250 product years ago - it was
> almost petty cash for an
> enterprise license)
>
> Anyway, I'm not ready to assume that this is a built in irritant, but
> Hyperterm and
> the base Telenet terminal emulation within Win/98Se works fine....
>
> Now if only my vms 7.3 media would showup....
>
> Villy
>
> Villy Madsen
> www.members.shaw.ca/villy.madsen
>
>
>
>
>
>
> From: Villy Madsen <Villy.Madsen at shaw.ca>
> Date: April 3, 2006 9:48:01 PM EDT
> To: "simh at trailing-edge.com" <simh at trailing-edge.com>
> Subject: [Simh] Ethernet Connectivity
> Reply-To: "Villy.Madsen at shaw.ca" <Villy.Madsen at shaw.ca>
>
>
> It appears that OPENVPNS is not an option to old fogies like me
>
> it doesn't like W/98SE at all..
>
> however
>
> downloading and installing a copy of the Nortel Contivity VPN client
> which appears to be available from a multitudious
> number of locations on the net, works as well - and it's Win98/SE
> friendly
>
> Villy
>
> Villy Madsen
> www.members.shaw.ca/villy.madsen
>
>
>
>
>
>
> From: Jay Mumper <jdmumper at comcast.net>
> Date: April 3, 2006 10:56:37 PM EDT
> To: Simh at trailing-edge.com
> Subject: [Simh] SIMH emulator running on Windows Mobile 2003?
>
>
> Just on a whim, has anyone gotten SIMH running on Windows Mobile
> 2003? The thought of carrying a running system that used to be the
> size of a room full of hardware in my pocket is pretty cool...
>
>
> --
> Jay Mumper
>
> From: "Zane H. Healy" <healyzh at aracnet.com>
> Date: April 4, 2006 12:16:28 AM EDT
> To: Jay Mumper <jdmumper at comcast.net>, Simh at trailing-edge.com
> Subject: Re: [Simh] SIMH emulator running on Windows Mobile 2003?
>
>
> At 10:56 PM -0400 4/3/06, Jay Mumper wrote:
>> Just on a whim, has anyone gotten SIMH running on Windows Mobile
>> 2003? The thought of carrying a running system that used to be the
>> size of a room full of hardware in my pocket is pretty cool...
>
> I know someone that had the PDP-11 SIMH emulator running on WinCE 2.0
> (I think that was the version) a few years ago. He wanted RSTS/E in
> his pocket.
>
> Zane
>
>
> --
> --
> | Zane H. Healy | UNIX Systems Administrator |
> | healyzh at aracnet.com (primary) | OpenVMS Enthusiast |
> | MONK::HEALYZH (DECnet) | Classic Computer Collector |
> +----------------------------------+----------------------------+
> | Empire of the Petal Throne and Traveller Role Playing, |
> | PDP-10 Emulation and Zane's Computer Museum. |
> | http://www.aracnet.com/~healyzh/ |
>
>
>
>
> From: "Tim Pinkawa" <timpinkawa at gmail.com>
> Date: April 4, 2006 12:47:13 AM EDT
> To: Simh at trailing-edge.com
> Subject: Re: [Simh] SIMH emulator running on Windows Mobile 2003?
>
>
> On 4/3/06, Zane H. Healy <healyzh at aracnet.com> wrote:
>> I know someone that had the PDP-11 SIMH emulator running on WinCE 2.0
>> (I think that was the version) a few years ago. He wanted RSTS/E in
>> his pocket.
>>
>> Zane
>
> I also have a PocketPC and would be interested in hearing if anyone
> has had success with this lately (SIMH 3.5). With a sufficiently large
> CompactFlash or Secure Digital card, OpenVMS from PocketPC would be
> pretty cool. :)
>
> Tim
>
>
>
>
> From: Mark Pizzolato <mark at infocomm.com>
> Date: April 4, 2006 3:59:58 AM EDT
> To: simh at trailing-edge.com
> Subject: Re: [Simh] No recognizable idle loop
> Reply-To: mark at infocomm.com
>
>
>
>
> --- bsupnik at comcast.net wrote:
>
>> I've seen this question so many times, here's the definitive
>> answer: there is no idle job or simple idle loop in VMS. Instead,
>> VMS loops in the scheduler (at IPL 3) waiting for interrupts or for
>> something to appear on a scheduler queue as a result of a higher
>> priority interrupt. Here is the code from VMS 7.2:
>>
>> 61$:
>> JSB G^EXE$PROC_IDLE ;SEE IF WE HAVE CPU SPECIFIC IDLE LOOP
>> BLBS R0,61$ ;NO - GO TO STANDARD LOOP
>> BBC #CPB$V_RUN,CPU$L_CAPABILITY(R3),70$ ; RUN CAPABILITY PRESENT?
>> BBS R1,G^SCH$GL_IDLE_CPUS,60$ ;LOOP UNTIL WE AREN'T IDLE
>> BRB 65$
>> 61$:
>> BBC #CPB$V_RUN,CPU$L_CAPABILITY(R3),80$ ; RUN CAPABILITY PRESENT?
>> TSTL G^SCH$GL_TBSH ; Class scheduler present?
>> BEQL 64$ ; No, see if still idle
>> JSB G^SCH$CLASS_IDLE ; Yes, see if TBS job runnable
>> 64$:
>> BBS R1,G^SCH$GL_IDLE_CPUS,61$ ;LOOP UNTIL WE AREN'T IDLE
>>
>> This varies from release to release as well.
>
> ... there looks to be a typo in the above since the label 61$ appears
> twice, the first probably should be 60$.
>
> The above code IS the idle loop. As it turns out, BBS taking the
> branch at IPL3 on the Interrupt stack only happens in the recent
> versions of VMS in the idle loop. No other OSes use IPL3 at all.
> The system will be spinning here until something fires due to an SCP
> event updates some data that will let the loop exit. I've had a
> completely working simulator which I believe properly addresses idle
> behaviors and doesn't soak the host cpu for several years now. It
> works with different detection code for the following cases:
>
> 1 - VMS - Old versions
> this was the old BRB point at self pre SMP VMS (prior to
> 5.0)
> 2 - VMS - recent versions
> 3 - Console input wait loops
> 4 - Ultrix - Whatever version I had to test with
> 5 - BSD Unix (NetBSD, Quasijarus)
>
> To get reasonable idle behavior, scp needs a little support to go
> into an idle state, and slightly extended timing semantics to attempt
> to keep the guest clock ticks and the rest of the event queue
> processed in reasonably consistent way.
>
> My implemention makes idle behavior an option in the case that
> someone likes to soak up his host CPU cycles, or writes a new OS
> which happens to catch one of the above idle detection conditions
> inappropriately. (or merely wants to compare the simulated and host
> system behavior with idle detection enabled).
>
> None of the above indicated idle cases currently seem to interfere
> with each other, however if someone felt they did, they could each be
> enabled separately - adding complexity to the management side.
>
> I'll be glad to try and merge this into a current simh version if
> requested by Bob. I've had this running on Windows, Linux and
> Solaris on Sparc and X86.
>
> - Mark Pizzolato
>
>> /Bob Supnik
>>
>>>
>>> Message: 5
>>> Date: Mon, 03 Apr 2006 08:55:43 -0600
>>> From: Villy Madsen <Villy.Madsen at shaw.ca>
>>> Subject: [Simh] VMS Idle loop
>>> To: simh at trailing-edge.com
>>> Message-ID: <69d691969d7ad0.69d7ad069d6919 at shaw.ca>
>>> Content-Type: text/plain; charset=us-ascii
>>>
>>> Does anyone have a clue what the vax/vms idle loop looks like..
>>>
>>> at one point in time I had been told it was just a
>>> BRB pointing to itself
>>>
>>> (so would that be brb 0 or brb -1 - it's been too many years and
>> and I can't
>>> remember).
>>>
>>>
>>> In case you are wondering, I am wondering if it would be possible
>> to build a
>>> throttle into the simulator so that it doesn' run wide open all
>> of the time...
>>>
>>> Villy
>>>
>>>
>>>
>>> ------------------------------
>>>
>>> _______________________________________________
>>> Simh mailing list
>>> Simh at trailing-edge.com
>>> http://mailman.trailing-edge.com/mailman/listinfo/simh
>>>
>>>
>>> End of Simh Digest, Vol 29, Issue 2
>>> ***********************************
>>
>>
>> _______________________________________________
>> Simh mailing list
>> Simh at trailing-edge.com
>> http://mailman.trailing-edge.com/mailman/listinfo/simh
>>
>>
>
>
>
>
> _______________________________________________
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> Simh at trailing-edge.com
> http://mailman.trailing-edge.com/mailman/listinfo/simh
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