HECnet

hecnet@lists.dfupdate.se

5 participants
15580 discussions

Emulated XQ polling timer setting and data overrun

by bqt＠softjar.se

On 2014-06-05 13:58, Mark Pizzolato - Info Comm wrote: On Thursday, June 05, 2014 at 1:27 AM, Johnny Billquist wrote: On 2014-06-05 02:38, Jean-Yves Bernier wrote: [...] I have tested commit 753e4dc9 on Mac OS 10.6, no virtualization. Both simh instances run on the same hardware. XQ set to different MAC addresses, since this is now enforced. Asynchronous network/disk IO may explain the uncommon transfer speed (I have filled a RM03 in seconds). Interesting. I still have real network issues with the latest simh talking to a real PDP-11 sitting on the same physical network. So you seem to have hit sime other kind of limitation or something... Can you elaborate on these 'real network issues'? This is the first I've heard of anything like this. I have not had any experience with a real PDP11 talking to a simh PDP or VAX, but in the past there were no issues with multiple simh VAX simulators talking to real VAX systems on the same LAN. Let me know. Same as I have talked about several times here. Doing file transfers from the simh system to the real PDP-11 gets horrible performance. It's a simple question of data overflow and loss, and DECnet performs poorly here because recovery from lost packets is so bad when you are loosing lots of packets. Nothing you really can do about it, unless you want to throttle the ethernet transmissions. Johnny

11 years, 3 months

Emulated XQ polling timer setting and data overrun

by Mark＠infocomm.com

On Thursday, June 05, 2014 at 1:27 AM, Johnny Billquist wrote: On 2014-06-05 02:38, Jean-Yves Bernier wrote: [...] I have tested commit 753e4dc9 on Mac OS 10.6, no virtualization. Both simh instances run on the same hardware. XQ set to different MAC addresses, since this is now enforced. Asynchronous network/disk IO may explain the uncommon transfer speed (I have filled a RM03 in seconds). Interesting. I still have real network issues with the latest simh talking to a real PDP-11 sitting on the same physical network. So you seem to have hit sime other kind of limitation or something... Can you elaborate on these 'real network issues'? This is the first I've heard of anything like this. I have not had any experience with a real PDP11 talking to a simh PDP or VAX, but in the past there were no issues with multiple simh VAX simulators talking to real VAX systems on the same LAN. Let me know. Thanks. - Mark

11 years, 3 months

Emulated XQ polling timer setting and data overrun

by bqt＠softjar.se

On 2014-06-05 02:38, Jean-Yves Bernier wrote: At 4:59 PM -0700 4/6/14, Mark Pizzolato - Info Comm wrote: Did you change the number of receive buffers? That does not seem possible under RSX. It is, but you need to do it in CFE. No way of dynamically changing at runtime. That really only indicates that you're running on a platform which can do Ethernet network I/O in a parallel thread. Most platforms did not use the threaded model previously. Previously, in 3.9, Polling was still necessary since the simulator didn't really support an asynchronous I/O model. The latest codebase has support for asynchronous network AND disk I/O. On the current codebase if you've got threads available, then network reads and writes are performed asynchronously and interrupts (I/O completion) is triggered with a few microseconds of latency. As I recall from earlier in these threads, you're running under CentOS on VirtualBox. You didn't mention what host OS you're running on. In any case, the threaded model might just work better in the virtual environment. I have tested commit 753e4dc9 on Mac OS 10.6, no virtualization. Both simh instances run on the same hardware. XQ set to different MAC addresses, since this is now enforced. Asynchronous network/disk IO may explain the uncommon transfer speed (I have filled a RM03 in seconds). Interesting. I still have real network issues with the latest simh talking to a real PDP-11 sitting on the same physical network. So you seem to have hit sime other kind of limitation or something... Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt at softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol

11 years, 3 months

Emulated XQ polling timer setting and data overrun

by Mark＠infocomm.com

On Jun 4, 2014 5:38 PM, Jean-Yves Bernier <bernier at pescadoo.net> wrote: > > At 4:59 PM -0700 4/6/14, Mark Pizzolato - Info Comm wrote: > > >Did you change the number of receive buffers? > > That does not seem possible under RSX. > > > >That really only indicates that you're running on a platform which > >can do Ethernet network I/O in a parallel thread. Most platforms > >did not use the threaded model previously. Previously, in 3.9, > >Polling was still necessary since the simulator didn't really > >support an asynchronous I/O model. The latest codebase has support > >for asynchronous network AND disk I/O. On the current codebase if > >you've got threads available, then network reads and writes are > >performed asynchronously and interrupts (I/O completion) is > >triggered with a few microseconds of latency. As I recall from > >earlier in these threads, you're running under CentOS on VirtualBox. > >You didn't mention what host OS you're running on. In any case, > >the threaded model might just work better in the virtual environment. > > > I have tested commit 753e4dc9 on Mac OS 10.6, no virtualization. Both > simh instances run on the same hardware. XQ set to different MAC > addresses, since this is now enforced. > > Asynchronous network/disk IO may explain the uncommon transfer speed > (I have filled a RM03 in seconds). I didn't notice you were not testing traffic between VAXes . The threaded network I/o buffers more traffic which could naturally avoid overruns. Disk I/o with RQ and RP are now asynchronous on VAX and PDP11. - Mark

11 years, 3 months

Emulated XQ polling timer setting and data overrun

by bernier＠pescadoo.net

At 4:59 PM -0700 4/6/14, Mark Pizzolato - Info Comm wrote: Did you change the number of receive buffers? That does not seem possible under RSX. That really only indicates that you're running on a platform which can do Ethernet network I/O in a parallel thread. Most platforms did not use the threaded model previously. Previously, in 3.9, Polling was still necessary since the simulator didn't really support an asynchronous I/O model. The latest codebase has support for asynchronous network AND disk I/O. On the current codebase if you've got threads available, then network reads and writes are performed asynchronously and interrupts (I/O completion) is triggered with a few microseconds of latency. As I recall from earlier in these threads, you're running under CentOS on VirtualBox. You didn't mention what host OS you're running on. In any case, the threaded model might just work better in the virtual environment. I have tested commit 753e4dc9 on Mac OS 10.6, no virtualization. Both simh instances run on the same hardware. XQ set to different MAC addresses, since this is now enforced. Asynchronous network/disk IO may explain the uncommon transfer speed (I have filled a RM03 in seconds). -- Jean-Yves Bernier

11 years, 3 months

Phase II

by paul_koning＠dell.com

Are there any Phase II implementations out there that could be downloaded and run on an emulator such as SIMH? DECnet/E for RSTS V7 would be great since I know that well, but something else would also be interesting. I m trying to make my DECnet/Python allow Phase II, as opposed to the standard one version back backward compatibility. That s not documented but it is perfectly doable. Finding a real test system is the tricky part. It would be really neat to be able to find one that uses the marginally documented intercept feature. Does anyone here know where that was used? I have a vague impression that TOPS-10 and/or TOPS-20 treated the front end PDP-11 like another node. so that would be the relay node and the 10 or 20 the end node in a Phase II star network. Is that correct? paul

11 years, 3 months

Emulated XQ polling timer setting and data overrun

by Mark＠infocomm.com

On Wednesday, June 04, 2014 at 4:08 PM, Jean-Yves Bernier wrote: At 10:44 AM -0700 4/6/14, Mark Pizzolato - Info Comm wrote: If you're going to drive this deeply into testing it would really be best if you ran with the latest code since your results may ultimately suggest code changes, AND the latest code may behave significantly different than the older versions. Independent of which codebase you're running, and since you're now tweaking the behavior of the simulated hardware, you may want to look at sim> SHOW XQ STATS and try to analyze the relationship between these stats and the ones the OS sees. Also, you may want to explore what happens if: NCP> DEFINE LINE QNA-0 RECEIVE BUFFER 32 Is done prior to starting your network... The limit of 32 may be different on different Operating Systems... Once again the latest code is available from: https://github.com/simh/simh/archive/master.zip Mark, what kind of magic did you perform on XQ? I tried commit 753e4dc9 and overruns are gone. No more NFT/FAL hangups. Transfer speed is higher than ever : 10000. blocks in 4 seconds. I can't believe it. This ROCKS. Significant changes have been made since 3.9, but I haven't seen substantial throughput differences. Did you change the number of receive buffers? Maybe the secret is here: sim> sh xq XQ address=17774440-17774457, vector=120, MAC=08:00:2B:AA:BB:01 type=DEQNA, polling=disabled, sanity=OFF leds=(ON,ON,ON) attached to eth0 "polling=disabled" That really only indicates that you're running on a platform which can do Ethernet network I/O in a parallel thread. Most platforms did not use the threaded model previously. Previously, in 3.9, Polling was still necessary since the simulator didn't really support an asynchronous I/O model. The latest codebase has support for asynchronous network AND disk I/O. On the current codebase if you've got threads available, then network reads and writes are performed asynchronously and interrupts (I/O completion) is triggered with a few microseconds of latency. As I recall from earlier in these threads, you're running under CentOS on VirtualBox. You didn't mention what host OS you're running on. In any case, the threaded model might just work better in the virtual environment. - Mark

11 years, 3 months

Emulated XQ polling timer setting and data overrun

by bernier＠pescadoo.net

At 10:44 AM -0700 4/6/14, Mark Pizzolato - Info Comm wrote: If you're going to drive this deeply into testing it would really be best if you ran with the latest code since your results may ultimately suggest code changes, AND the latest code may behave significantly different than the older versions. Independent of which codebase you're running, and since you're now tweaking the behavior of the simulated hardware, you may want to look at sim> SHOW XQ STATS and try to analyze the relationship between these stats and the ones the OS sees. Also, you may want to explore what happens if: NCP> DEFINE LINE QNA-0 RECEIVE BUFFER 32 Is done prior to starting your network... The limit of 32 may be different on different Operating Systems... Once again the latest code is available from: https://github.com/simh/simh/archive/master.zip Mark, what kind of magic did you perform on XQ? I tried commit 753e4dc9 and overruns are gone. No more NFT/FAL hangups. Transfer speed is higher than ever : 10000. blocks in 4 seconds. I can't believe it. This ROCKS. Maybe the secret is here: sim> sh xq XQ address=17774440-17774457, vector=120, MAC=08:00:2B:AA:BB:01 type=DEQNA, polling=disabled, sanity=OFF leds=(ON,ON,ON) attached to eth0 "polling=disabled" -- Jean-Yves Bernier

11 years, 3 months

DEC Notes conference archive

by mcguire＠neurotica.com

On 06/04/2014 05:34 PM, John Dohn wrote: Hi, guys! Do anyone have archive of conferences mentioned at http://www.buschdorf.eu/vaxnotes/ ? I sure hope so. It looks like the suits got to it! -Dave -- Dave McGuire, AK4HZ New Kensington, PA

11 years, 3 months

DEC Notes conference archive

by xdelta＠meta.ua

Hi, guys! Do anyone have archive of conferences mentioned at http://www.buschdorf.eu/vaxnotes/ ? -- Best Regards

11 years, 3 months

Jump to page:

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

HECnet