[erlang-questions] beam process dies with code 135 (SIGBUS)

[Mikael Pettersson]

Vlad Dumitrescu writes:
 > Hi!
 > 
 > Does anyone have any experience of runtimes dying with code 135,
 > meaning by signal 7 (SIGBUS) (i.e. Bus error (bad memory access)) on
 > Linux?
 > 
 > We have seen nodes going down with this reason relatively often (but
 > randomly) and I don't know how to locate the problem. There doesn't
 > seem to be any code dump.

SIGBUS on x86 can AFAIK only be triggered by alignment errors,
which for x86 user-mode code means largish data transfers using
SSE instructions.

(That is, unless the environment foolishly sets the #AC bit in
eflags, in which case even plain misaligned integer loads/stores
will trap.)

Debugging this requires a core dump and the corresponding beam
executable. If you're not getting core dumps, see if they've
been disabled by default (man ulimit or limit).