[erlang-questions] Unexpected limitations

Danil Zagoskin z@REDACTED
Wed Mar 27 07:31:39 CET 2013


Hi, Stu.

Does your beam crash when you call lists:duplicate(100000000, a) ?

The difference is lists:duplicate is tail-recursive while lists:seq and
big_lists:make_list are body-recursive so you can hit some stack size
limit, not lists length one.


2013/3/27 Stu Bailey <stu.bailey@REDACTED>

> Hi all,
>
> I have an 8 core MacBook Pro Retina Display with 16GB of memory.   I am
> running R16B with no configure options...but I did install
> libatomic_ops-7.2 .     I tried a very simple list allocation test which
> surprisingly failed with a list size of 100 million.    I first made a list
> with 10 million integers.   The beam hung on 100 million.   Thinking it was
> something with lists:seq, I just wrote a dumb test to build big lists of
> single character atoms.  That also failed at 100 million.   Is there a
> known limitation to the size of lists in Erlang?
>
> bash-3.2$ uname -a
> Darwin myhost.local 12.3.0 Darwin Kernel Version 12.3.0: Sun Jan  6
> 22:37:10 PST 2013; root:xnu-2050.22.13~1/RELEASE_X86_64 x86_64
>
> bash-3.2$ erl
> Erlang R16B (erts-5.10.1) [source] [smp:8:8] [async-threads:10] [hipe]
> [kernel-poll:false]
>
> My Erlang Environment
> Eshell V5.10.1  (abort with ^G)
> 1> lists:seq(1,10000000).
> [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,
>  23,24,25,26,27,28,29|...]
> 2> lists:seq(1,100000000).
> beam.smp(85491,0xb039d000) malloc: *** mmap(size=458227712) failed (error
> code=12)
>
>         *** error: can't allocate region
>
>                                         *** set a breakpoint in
> malloc_error_break to debug
>         beam.smp(85491,0xb039d000) malloc: *** mmap(size=659554304) failed
> (error code=12)
>
>                 *** error: can't allocate region
>
>                                                 *** set a breakpoint in
> malloc_error_break to debug
>                 beam.smp(85491,0xb039d000) malloc: ***
> mmap(size=791674880) failed (error code=12)
>
>                         *** error: can't allocate region
>
>                                                         *** set a
> breakpoint in malloc_error_break to debug
>                         beam.smp(85491,0xb039d000) malloc: ***
> mmap(size=791674880) failed (error code=12)
>
>                                 *** error: can't allocate region
>
>                                                                 *** set a
> breakpoint in malloc_error_break to debug
>                                 beam.smp(85491,0xb039d000) malloc: ***
> mmap(size=791674880) failed (error code=12)
>
>                                         *** error: can't allocate region
>
>                                                                         ***
> set a breakpoint in malloc_error_break to debug
>                                         beam.smp(85491,0xb039d000) malloc:
> *** mmap(size=790962176) failed (error code=12)
>
>                                                 *** error: can't allocate
> region
>
>
>     *** set a breakpoint in malloc_error_break to debug
>                                                 beam.smp(85491,0xb039d000)
> malloc: *** mmap(size=790962176) failed (error code=12)
>
>                                                         *** error: can't
> allocate region
>      *** set a breakpoint in malloc_error_break to debug
>                                                         Killed: 9
>
>
> ================
>
>  -module(big_lists).
>
> -compile([export_all]).
>
>
> make_list(0,Acc)->
>     Acc;
> make_list(Size,Acc) ->
>     make_list(Size-1, [a] ++ Acc).
>
> ===================
>
> 5> c(big_lists).
> {ok,big_lists}
> 6> big_lists:make_list(2,[]).
> [a,a]
> 7> big_lists:make_list(100000,[]).
> [a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a|...]
> 8> big_lists:make_list(1000000,[]).
> [a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a|...]
> 9> big_lists:make_list(10000000,[]).
> [a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a|...]
> 10> big_lists:make_list(100000000,[]).
> beam.smp(85534,0xb039d000) malloc: *** mmap(size=381681664) failed (error
> code=12)
>
>         *** error: can't allocate region
>
>                                         *** set a breakpoint in
> malloc_error_break to debug
>         beam.smp(85534,0xb039d000) malloc: *** mmap(size=659554304) failed
> (error code=12)
>
>                 *** error: can't allocate region
>
>                                                 *** set a breakpoint in
> malloc_error_break to debug
>                 beam.smp(85534,0xb039d000) malloc: ***
> mmap(size=791674880) failed (error code=12)
>
>                         *** error: can't allocate region
>
>                                                         *** set a
> breakpoint in malloc_error_break to debug
>
> [a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a,a|...]
> beam.smp(85534,0xb039d000) malloc: *** mmap(size=950009856) failed (error
> code=12)
>
>         *** error: can't allocate region
>
>                                         *** set a breakpoint in
> malloc_error_break to debug
>         beam.smp(85534,0xb039d000) malloc: *** mmap(size=950009856) failed
> (error code=12)
>
>                 *** error: can't allocate region
>
>                                                 *** set a breakpoint in
> malloc_error_break to debug
>                 beam.smp(85534,0xb039d000) malloc: ***
> mmap(size=949153792) failed (error code=12)
>
>                         *** error: can't allocate region
>
>                                                         *** set a
> breakpoint in malloc_error_break to debug
>                         beam.smp(85534,0xb039d000) malloc: ***
> mmap(size=949153792) failed (error code=12)
>
>                                 *** error: can't allocate region
>
>                                                                 *** set a
> breakpoint in malloc_error_break to debug
>
> Crash dump was written to: erl_crash.dump
> eheap_alloc: Cannot allocate 949152844 bytes of memory (of type "heap").
> Abort trap: 6
>
>
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