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Crystal Pellet
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Message 27967 - Posted: 26 Nov 2016, 10:28:44 UTC

On my Windows7 machine SixTrack tasks use very low CPU after the start (5%).
This can go up up to 55 minutes almost idling and then suddenly the tasks are using a full core.
This is happening with the 2 kinds of SixTrack applications I got fo far: pni and sse2.
What's happening or what's wrong with my machine.

https://lhcathome.cern.ch/lhcathome/results.php?hostid=10362384&offset=0&show_names=0&state=4&appid=

On the same hardware the Linux tasks are doing well.

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Message 27968 - Posted: 26 Nov 2016, 16:02:45 UTC

I noticed something similar on my Windows 10 machine.

When a Sixtrack task started, it used about 40% of a thread until the task was ~7% complete (~3 minutes). Then the % complete jumped back to almost 0% and it started using 100% of a thread.

Harri Liljeroos
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Message 27970 - Posted: 27 Nov 2016, 9:35:38 UTC

The low CPU usage in the beginning of sixtrack is normal. While the application uses little CPU the load is on Windows system programs (conhost and csrss). I reported this earlier, you see it here https://lhcathome.cern.ch/lhcathome/forum_thread.php?id=3998#27788
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Message 27972 - Posted: 27 Nov 2016, 15:37:03 UTC - in response to Message 27970.
Last modified: 27 Nov 2016, 16:42:34 UTC

Thanks Harri for the link. Before posting I searched for 'low cpu' and not for 'High non-Boinc CPU', so I didn't find something useful.

However I had tasks up to 55 minutes low application usage on a 30-core Windows-VM and not on a 14-core Linux-VM or on a 8-core Win7 host.

During that 'long' startup phase (BOINC CPU-setting 100%) OS task monitor was much lower then the maximum - about 40-50% maybe.
I'll see and try to monitor that behaviour - else I'll detach LHC@home from that machine - too much CPU-waste.

Edit: If I could get SixTrack tasks.

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Message 27988 - Posted: 28 Nov 2016, 16:17:18 UTC

I got 4 SixTrack's on that 30 core machine and monitored the low cpu behaviour of the sixtrack_win32_4517_sse2.exe.
During the first 12 minutes almost no CPU-usage, but saw csrss.exe using about 20% of 1 core and a conhost.exe (child of csrss) using about the same.
After those 12 minutes the 2 above mentioned processes sleep and sixtrack_win32_4517_sse2.exe started to use a whole core.

Maybe running more tasks concurrently may slow down the init-phase much more.

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Message 27991 - Posted: 28 Nov 2016, 18:22:00 UTC

Maybe running more tasks concurrently may slow down the init-phase much more.

I did a new test with 21 concurrent tasks.
The single csrss.exe used about 2 cores of CPU-time and the 21 conhost.exe's together about 3 cores.
The 'idle' period of the 21 SixTrack.exe's lasted almost 43 minutes.

Note: I'm running this BOINC in a Virtual Machine (Win7) (VMWare) - maybe related.
I'll later test on a 8-core Win7 host directly and see how the SixTrack behave there.

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Message 27993 - Posted: 28 Nov 2016, 21:17:09 UTC - in response to Message 27991.

I'll later test on a 8-core Win7 host directly and see how the SixTrack behave there.

Same behaviour with 8 tasks running, but 'idle' time of the SixTrack.exe's was much shorter.
'Only' a bit over 3 minutes, where csrss.exe used about 1 core and the 8 conhost.exe's together about 2 cores.

Have to add that on this machine, I only got the 64bit version sixtrack_win64_4517_sse2.exe.
Can the server not been told not to send 32bit tasks to a 64bit machine?

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Message 27994 - Posted: 28 Nov 2016, 22:03:48 UTC - in response to Message 27993.

Can the server not been told not to send 32bit tasks to a 64bit machine?

See: http://boinc.berkeley.edu/wiki/client_configuration
You may set the following option in your cc_config.xml:
<no_alt_platform>0|1</no_alt_platform>
If enabled, the client will run applications only for its primary platform. For example, a Win64 machine will run only Win64 apps, and not Win32.

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Message 27995 - Posted: 28 Nov 2016, 22:20:49 UTC - in response to Message 27994.

You may set the following option in your cc_config.xml:
<no_alt_platform>0|1</no_alt_platform>
If enabled, the client will run applications only for its primary platform. For example, a Win64 machine will run only Win64 apps, and not Win32.

Yeah, I know, but this setting is BOINC-wide and you will also not get tasks from projects only providing 32bit applications.

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Message 28001 - Posted: 29 Nov 2016, 18:04:48 UTC

Dear All, thanks for your feedback. We had some previous discussion at
https://lhcathome.cern.ch/lhcathome/forum_thread.php?id=3998#27788
I did try some tests on my Windows 7 box (4 threads) and indeed Windows
was very slow to start SixTrack.

SixTrack has three phases, pre-processing, tracking, and post-processing.
The tracking is almost all CPU and may last from 0 seconds (unstable beam)
or for several hours.
The pre-processing should take less than 1 minute, but involves a lot
of file opens (more than 60) and some I/O.
My own tests on 4 threads do show very slow pre-processing but not as bad as described
by you.
I think the Windows task
scheduling is very poor . There may also be locking issues on a multi-core
system, especially as we are running an old executable from Windows XP
from more than 2 years ago! (This is a very nasty problem. I cannot build
the BOINC API libraries on Windows 7 or 10 and CERN has abolished
XP. I want to use gfortran and gcc as the ifort compiler for Windows is not
numerically compatible. I used to use cygwin but I can't install it anymore becuase
of some Tex very large files never completing (known problem.). I am trying
MinGW (we do NOT use Visual Studio) but the script seems out of date.
I have also tried xcompile but gfortran seems to be installed in the wrong place....
I really must get some help from my Windows support at CERN or from other projects.)
Eric.
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Message 28006 - Posted: 30 Nov 2016, 7:27:49 UTC

Hi Eric, maybe you could talk to David from the BOINC team to get some help with building the BOINC libraries? He seems active with the ATLAS project team.

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Message 28163 - Posted: 20 Dec 2016, 15:16:56 UTC - in response to Message 28001.

Have you considered MSYS2? It is more up-to-date than MSYS. I have used it with NetBeans as an IDE on Windows 10 and it seems to work OK.
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Message 28214 - Posted: 22 Dec 2016, 20:36:51 UTC

This time I got a bunch SixTrack tasks on the same Windows machine , where I reported the low cpu-usage,
but now I got only pni-tasks (32- and 64bits) and now the init-phase was only 12 seconds.

In OP-mentioned tasks weren't pni and those longer running tasks had a CPU efficiency of 88%.
Today the CPU-efficiency of the longer running pni-tasks was 99,6%.

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Message 28219 - Posted: 23 Dec 2016, 9:21:26 UTC - in response to Message 28006.

Thanks Toby, I am getting some help from Einstein@home and I have now
managed to build two out of three libs I need. I am still missing the zip. Eric.
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Message 28220 - Posted: 23 Dec 2016, 9:22:04 UTC - in response to Message 28163.

Good point, I'll check that I am indeed using msys2. Eric.
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Message 28221 - Posted: 23 Dec 2016, 9:44:52 UTC - in response to Message 28214.

Thanks for this feedback. If you have SSE/PNI you should indeed get the sse2 or sse3
executable. I am working on all this. Eric.
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Message 28222 - Posted: 23 Dec 2016, 9:46:44 UTC
Last modified: 23 Dec 2016, 10:04:35 UTC

The issue seems to be batch specific.
Today tasks have the same issue: low cpu usage of the sixtrack executable and 1 csrss.exe some cpu depending how many tasks are running and for each task 1 conhost.exe a bit of cpu.

1 workunit (the first returned one is mine): https://lhcathome.cern.ch/lhcathome/workunit.php?wuid=52870548

You see the big difference between run time and cpu time.
There was cpu left on that system and BOINC is allowed to use 100%.

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Message 28809 - Posted: 7 Feb 2017, 14:05:04 UTC

I digged a bit more into these tasks on Windows with very low CPU-usage at the start.
When starting a single task about 11 minutes at the start the CPU-usage is between 10% and 20%.
When the real processing starts a lot of tasks thereafter are ready within 2 minutes.
When starting more tasks at once these low CPU-time increases up to over one hour when all 30 cores are used.

In my former post I already mentioned the issue seems to be batch specific.

All tasks starting their names with w-c8_lhc2016 and w-c9_lhc2016 don't suffer from these long idling timeouts during the first phase.

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Message 29098 - Posted: 7 Mar 2017, 14:19:29 UTC

Any progress? With CPU 100% allowed on a Windows 7 machine:

LHC@home w4_hllhc10_round_a4b5_000v665_w4__51__s__62.31_60.32__2_4__5__22.5_1_sixvf_boinc11730_1 451.07 SixTrack (pni) elapsed 00:35:08 CPU 00:00:07

After 36 minutes real processing started.

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Message 30917 - Posted: 21 Jun 2017, 15:40:34 UTC
Last modified: 21 Jun 2017, 15:41:35 UTC

Show it with a picture. 30 threads, first started 15 Sixtracks and after half an hour the other 15.
Taking the picture one task was uploaded and acknowledged https://lhcathome.cern.ch/lhcathome/result.php?resultid=147624816
In the column v2 you see the elapsed time and (used cpu time). So real processing started after 28 minutes.

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Message boards : Sixtrack Application : Very low CPU-usage on Windows with SixTrack tasks