@parallel (+) segmentation fault on arm #13508
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dasGringuen opened this Issue on Oct 9, 2015 · 4 comments
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@dasGringuen
@tkelman
@ViralBShah
@yuyichao
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@dasGringuen
dasGringuen commented on Oct 9, 2015

Hello

we are running Julia on the Red Pitaya platform using Debian Jessie armhf.
Were are getting a segmentation fault while running the next code.
You can find the code and the error log while running it with gdb.

Any hints?

Many thanks,
Adrian
Julia version:

root@red-pitaya:~/julia# ./julia 
               _
   _       _ _(_)_     |  A fresh approach to technical computing
  (_)     | (_) (_)    |  Documentation: http://docs.julialang.org
   _ _   _| |_  __ _   |  Type "?help" for help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 0.4.0-rc4 (2015-10-04 03:14 UTC)
 _/ |\__'_|_|_|\__'_|  |  
|__/                   |  arm-linux-gnueabihf

julia> 

Code:

root@red-pitaya:~/julia# cat multicore_forloop.jl
#A microbenchmark to demonstrate the effect of parallel for loops
#
#$author: Manfred Mücke
#$created: 20.9.2015
#$lastchange: 29.9.2015
#

println ("==== multicore_forloop.jl ====")
println ("Julia version: $VERSION")

#remove all workers which might be around
rmprocs(workers())
println("Sequential run - available processes: $(nprocs()) ")

@everywhere n=5000000 # to scale test size


#------------------sequential
s_s=0
for i = 1:n #first run
  s_s += i^2
end
s_s=0
t_seq = @elapsed for i = 1:n #measure
  s_s += i^2
end

#add four worker processes on local machine
addprocs(4)
println("Parallel run - available workers: ",nworkers())


#------------------parallel
@everywhere s_p=0
s_p = @parallel (+) for i = 1:n # first run
  i^2
end
@sync @everywhere sleep(1) # global barrier

t_par = @elapsed @parallel (+) for i = 1:n # measure
  i^2
end

if (myid() == 1)
  println ("Results match: $(s_p == s_s) ($s_p, $s_s)")
  println (" Sequential: \t$t_seq\n Parallel: \t$t_par\n Speed-Up: \t$(t_seq/t_par)\n")
  println ("===============================================")
end

#remove all workers which might be around
#rmprocs(workers())

Gdb log

root@red-pitaya:~/julia# gdb --args ./julia ./multicore_forloop.jl 
GNU gdb (Debian 7.7.1+dfsg-5) 7.7.1
Copyright (C) 2014 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later 
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "arm-linux-gnueabihf".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
.
Find the GDB manual and other documentation resources online at:
.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from ./julia...done.
(gdb) r
Starting program: /root/julia/julia ./multicore_forloop.jl
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/arm-linux-gnueabihf/libthread_db.so.1".
[New Thread 0x12d20450 (LWP 10644)]

WARNING: deprecated syntax "println (" at /root/julia/multicore_forloop.jl:15.
Use "println(" instead.
==== multicore_forloop.jl ====

WARNING: deprecated syntax "println (" at /root/julia/multicore_forloop.jl:17.
Use "println(" instead.
Julia version: 0.4.0-rc4
WARNING: rmprocs: process 1 not removed
Sequential run - available processes: 1 

signal (11): Segmentation fault

signal (11): Segmentation fault

signal (11): Segmentation fault

signal (11): Segmentation fault
[New Thread 0x10d4a450 (LWP 10653)]
[New Thread 0x1054a450 (LWP 10654)]
[New Thread 0xfd4a450 (LWP 10655)]
[New Thread 0xf54a450 (LWP 10656)]
ERROR: LoadError: connect: connection refused (ECONNREFUSED)

...and 3 other exceptions.

while loading /root/julia/multicore_forloop.jl, in expression starting on line 55
UndefRefError()
[Thread 0xf54a450 (LWP 10656) exited]
[Thread 0x1054a450 (LWP 10654) exited]
[Thread 0xfd4a450 (LWP 10655) exited]
[Thread 0x10d4a450 (LWP 10653) exited]
[Thread 0x36ff1000 (LWP 10641) exited]
[Inferior 1 (process 10641) exited with code 01]

@tkelman tkelman added the arm label on Oct 9, 2015
@dasGringuen
dasGringuen commented on Oct 15, 2015

Hello,

I have tried also with a Raspberry pi and I'm getting the same segmentation fault errors.
I followed the ARM compilation guide, enabled the debugging information and run it with GDB.
Next you can find a more detailed output.

Could you please suggest how to proceed. We are looking forward on tracking this issue and fixing it.

Regards,
Adrian
Versioninfo()

julia> versioninfo()
Julia Version 0.4.0
Commit 0ff703b (2015-10-08 06:20 UTC)
DEBUG build
Platform Info:
  System: Linux (arm-linux-gnueabihf)
  CPU: ARMv7 Processor rev 5 (v7l)
  WORD_SIZE: 32
  BLAS: libblas
  LAPACK: liblapack
  LIBM: libm
  LLVM: libLLVM-3.6.1

Make.user

pi@raspberrypi ~/julia $ cat Make.user 
FORCE_ARMV7=1
LLVM_ASSERTIONS=1

override USE_SYSTEM_BLAS=1
override USE_SYSTEM_LAPACK=1
override USE_SYSTEM_LIBM=1
override USE_SYSTEM_FFTW=1
override USE_SYSTEM_GMP=1
override USE_SYSTEM_MPFR=1
override USE_SYSTEM_ARPACK=1

@tkelman
The Julia Language member
tkelman commented on Oct 15, 2015

Best to use something separate like gist.github.com to post long logs, with just links here so this page isn't as bad to scroll through. Someone with access to an arm build will have to look into this.
@ViralBShah
The Julia Language member
ViralBShah commented on Nov 25, 2015

I trimmed the output above. Also, this is easily reproduced just with:

viral@julia-arm:~/julia$ ./julia -p 2
WARNING: unable to determine host cpu name.
WARNING: unable to determine host cpu name.
WARNING: unable to determine host cpu name.

signal (11): Segmentation fault
while loading no file, in expression starting on line 0

signal (11): Segmentation fault
while loading no file, in expression starting on line 0

@ViralBShah ViralBShah added the parallel label on Nov 25, 2015
@maleadt maleadt referenced this issue on Nov 30, 2015
Merged
ARM ABI #14194
@yuyichao
The Julia Language member
yuyichao commented on Jan 5

Close as a direct dup of #12344 (and almost all of these issues on ARM) are just due to incompatible C ABI. Please feel free to report additional issues with @parallel on ARM after #14194 is merged.
@yuyichao yuyichao closed this on Jan 5