NFD » ndn-cxx

This problem appears on Nov 09.

To prevent its impact on normal workflow, Ubuntu 14.10 slaves are disabled on the same day.

I'll try to reproduce this bug and determine whether it's an out-of-memory condition.

I have concluded that this bug is a out-of-memory condition. This conclusion is based on the observation below.

I'm using a Ubuntu 14.10 box with 2GB memory.
In the normal case, the compilation can succeed.
The compilation command used is:

./waf configure --with-tests
./waf -j1

Then I wrote a memory allocation program that allocates a specific amount of memory:

#include <stdlib.h>
#include <stdio.h>

int
main()
{
  void* buf = calloc(768, 1024 * 1024);
  printf("allocated %llx\n", (long long)buf);
  getchar();
  return 0;
}

"768" is the amount of memory, in MB, that this program is going to allocate.

calloc needs to zero the memory, which causes OS to allocate physical memory.

malloc does not cause OS to allocate physical memory until a page is touched, so it shouldn't be used.

Then I executed compilation command while the memory allocation program is running.
By adjusting the amount of memory allocated, three different error messages are observed:

1536MB:

[  2/174] Compiling src/common-pch.hpp
virtual memory exhausted: Cannot allocate memory

1024MB:

[  2/174] Compiling src/common-pch.hpp

cc1plus: out of memory allocating 67108864 bytes after a total of 215019520 bytes

768MB:

[  5/174] Compiling tests/unit-tests/encoding/nfd-constants.cpp

g++: internal compiler error: Segmentation fault (program cc1plus)
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.9/README.Bugs> for instructions.

The third error message matches the one in this Bug report.

Proposed solution:

• in INSTALL.rst "Prerequisites" section, add "1.5GB available memory"
• in INSTALL.rst "Build" and "Development Build" section, change ./waf to ./waf -j1

I have tested that compilation can succeed if the memory allocation program takes away 512MB, so "1.5GB" is recommended.

http://gerrit.named-data.net/1488

I'm reassigning this issue to @Yi.

System processes on Ubuntu 14.10 slaves take 1GB memory.
Thus, total memory on these slaves shall be set to 2560MB, so that there are 1.5GB available memory for compilation, as recommended by the new documentation.

This Bug can close after 7 days if there's no more such failure.