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Posts by Carsten Milkau

1) Message boards : Number crunching : Always immediate segfault on MilkyWay@Home N-Body Simulation v1.62 (mt) (Message 65044)
Posted 18 Aug 2016 by Carsten Milkau
Post:
I successfully ran MilkyWay@Home N-Body Simulation v1.62 (mt) on the following setup:
    ENABLED vsyscall emulation (supports <glibc2.14)
    enabled heap randomization (breaks libc5)
    disabled uselib syscall (breaks libc5)



So nbody seems to use a lib requiring vsyscall, likely some glibc version prior to 2.14.

As the other milkyway apps don't require vsyscall (and there's a small security impact in emulating it), I'll just disable nbody for now, and occasionally check back to see if a newer version works.

2) Message boards : Number crunching : Always immediate segfault on MilkyWay@Home N-Body Simulation v1.62 (mt) (Message 65043)
Posted 18 Aug 2016 by Carsten Milkau
Post:
I identfied three possibly related settings:
    Disabled vsyscall (breaks <glibc-2.14)
    Enabled heap randomization (breaks libc5)
    Disable uselib syscall (breaks libc5)


I'll post results. As these are security related settings, I'll changr them only temporarily and keep nbody sim disabled.

The standard milkyway and milkyway opencl apps run just fine, are you using newer libs for those?

3) Message boards : Number crunching : Always immediate segfault on MilkyWay@Home N-Body Simulation v1.62 (mt) (Message 65040)
Posted 17 Aug 2016 by Carsten Milkau
Post:
Erm, as I mentioned, this happens with *every* WU (of this app) for me.
I have more than 100 failed tasks. It's always immediate segfault.

I checked many of them, most belong to WU with both failed and successful runs (for other user). But I didnt see many other crashes, mostly the disk usage problem.

So it looks a bit specific to me. Unfortunately I dont know how zo obtain more information.

P.S. I noticed the app is statically linked. Do you use different libraries or a different compiler for nbody? The segfaults are so early they are likely still during initialization. I recently disabled kernel support for some very old compilers / c libraries.
4) Message boards : Number crunching : Always immediate segfault on MilkyWay@Home N-Body Simulation v1.62 (mt) (Message 65038)
Posted 17 Aug 2016 by Carsten Milkau
Post:
N-Body sim always crashes immediately (0 secs CPU) with segmentation fault.
    - I wasn't able to enforce a non-mt version for testing.
    - Other Milkyway@home apps run fine.
    - Ran a memtest on all cpus in parallel just to make sure it's not hardware. All fine.

For instance, see:
[1] http://milkyway.cs.rpi.edu/milkyway/result.php?resultid=1731129208
[2] http://milkyway.cs.rpi.edu/milkyway/workunit.php?wuid=1270553147

5) Message boards : Number crunching : All WU crash with permission error (Message 61833)
Posted 3 Jun 2014 by Carsten Milkau
Post:
See e.g.
http://milkyway.cs.rpi.edu/milkyway/result.php?resultid=758337201

Boinc runs on niceness 19 on my system. I think this is reasonable. However, it seems the milkyway tasks attempt to set priority to 0, which fails.

I guess that attempt to an priority upgrade is an error in the first place? If there is a reason to run at higher process priority than "background" please tell me, maybe I can find a way to make that work.
6) Message boards : Number crunching : Computation errors (Message 57465)
Posted 9 Mar 2013 by Carsten Milkau
Post:
Got a different kind of error, which fails all WU immediately:

<core_client_version>7.0.29</core_client_version>
<![CDATA[
<message>
process exited with code 1 (0x1, -255)
</message>
<stderr_txt>
<search_application> milkyway_separation 1.02 Linux x86_64 double OpenCL </search_application>
Unrecognized XML in project preferences: max_gfx_cpu_pct
Skipping: 20
Skipping: /max_gfx_cpu_pct
Unrecognized XML in project preferences: allow_non_preferred_apps
Skipping: 1
Skipping: /allow_non_preferred_apps
Unrecognized XML in project preferences: nbody_graphics_poll_period
Skipping: 30
Skipping: /nbody_graphics_poll_period
Unrecognized XML in project preferences: nbody_graphics_float_speed
Skipping: 5
Skipping: /nbody_graphics_float_speed
Unrecognized XML in project preferences: nbody_graphics_textured_point_size
Skipping: 250
Skipping: /nbody_graphics_textured_point_size
Unrecognized XML in project preferences: nbody_graphics_point_point_size
Skipping: 40
Skipping: /nbody_graphics_point_point_size
BOINC GPU type suggests using OpenCL vendor 'NVIDIA Corporation'
Setting process priority to 0 (13): Permission denied
Opening Lua script 'astronomy_parameters.txt' (2): No such file or directory
Error reading astronomy parameters from file 'astronomy_parameters.txt'
Trying old parameters file
Opening astronomy parameters file 'astronomy_parameters.txt' (2): No such file or directory
Failed to read parameters file

20:40:09 (12990): called boinc_finish

</stderr_txt>
]]>

I completely removed and re-initialized the project several times without any luck. Apparantly GPU tasks need this file but don't download it.

http://milkyway.cs.rpi.edu/milkyway/result.php?resultid=415923043
http://milkyway.cs.rpi.edu/milkyway/results.php?userid=765878&state=5




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