Re: Erlang JIT and loaded code

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On Tue, Apr 26, 2022 at 7:36 AM Vitor Rocha <[email protected]> wrote:

> I managed to get the code size (I suppose) from internal structures:
>
>    - erl_module_instance->code_length (for emulator and asm)
>    - erl_module_instance->hipe_code->text_segment_size (for HiPE and
>    ErLLVM)
>
> Does that make sense or are those values unrelated?
>

I think those values make sense to compare.

Looking through the code I actually found a way to get the size of the
modules. If you do Ctrl+C to enter break mode and then type `l` you will
get a listing of all modules and their size in bytes. Not sure if that
functionality works for hipe code or not.


> Em seg., 25 de abr. de 2022 =C3=A0s 06:13, Lukas Larsson <[email protected]=
g>
> escreveu:
>
>> Hello!
>>
>> On Tue, Apr 19, 2022 at 7:17 AM Vitor Rocha <[email protected]> wrote:
>>
>>> (1) how do I know if my code is actually being executed as interpreted
>>> or native?
>>>
>>
>> All code loaded from .beam files are run natively if the VM supports JIT
>> compilation.
>>
>>
>>> (2) If I compile a module inside Erlang's shell, using the `c:c/1`
>>> function, is the module going to be compiled to native too? Will its
>>> execution be switched to native?
>>>
>>
>> There is no difference in how it is compiled, it will always be
>> translated into native code when loaded.
>>
>>
>>> (3) Where is stored the generated beamasm native code? I would like to
>>> get its size in bytes?
>>>
>>
>> It is stored in memory of the VM. You can get a file dump of the native
>> code by passing `+JDdump true` when starting `erl`. There is no way to g=
et
>> the loaded memory size of a single module, but you can get a relatively
>> close value by checking what `erlang:memory(code)` returns before and af=
ter
>> the module is loaded.
>>
>>
>>>
>>> --
>>> Atenciosamente,
>>> Vitor Rocha da Silva
>>>
>>
>
> --
> Atenciosamente,
> Vitor Rocha da Silva
>

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<div dir=3D"ltr"><div dir=3D"ltr"><br></div><br><div class=3D"gmail_quote">=
<div dir=3D"ltr" class=3D"gmail_attr">On Tue, Apr 26, 2022 at 7:36 AM Vitor=
 Rocha &lt;<a href=3D"mailto:[email protected]">[email protected]</a>&g=
t; wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0p=
x 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div d=
ir=3D"ltr"><div>I managed to get the code size (I suppose) from internal st=
ructures:<br></div><div><ul><li>erl_module_instance-&gt;code_length (for em=
ulator and asm)</li><li>erl_module_instance-&gt;hipe_code-&gt;text_segment_=
size (for HiPE and ErLLVM)</li></ul><div>Does that make sense or are those =
values unrelated?<br></div></div></div></blockquote><div><br></div><div>I t=
hink those values make sense to compare.</div><div><br></div><div>Looking t=
hrough the code I actually found a way to get the size of the modules. If y=
ou do Ctrl+C to enter break mode and then type `l` you will get a listing o=
f all modules and their size in bytes. Not sure if that functionality works=
 for hipe code or not.</div><div><br></div><blockquote class=3D"gmail_quote=
" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);=
padding-left:1ex"><div dir=3D"ltr"><div><div></div></div></div><br><div cla=
ss=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">Em seg., 25 de abr=
. de 2022 =C3=A0s 06:13, Lukas Larsson &lt;<a href=3D"mailto:[email protected]=
rg" target=3D"_blank">[email protected]</a>&gt; escreveu:<br></div><blockquo=
te class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px =
solid rgb(204,204,204);padding-left:1ex"><div dir=3D"ltr"><div>Hello!</div>=
<br><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Tue=
, Apr 19, 2022 at 7:17 AM Vitor Rocha &lt;<a href=3D"mailto:vitor.vrs@gmail=
.com" target=3D"_blank">[email protected]</a>&gt; wrote:<br></div><blockq=
uote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1p=
x solid rgb(204,204,204);padding-left:1ex"><div dir=3D"ltr"><div>(1) how do=
 I know if my code is actually being executed as interpreted or native?</di=
v></div></blockquote><div><br></div><div>All code loaded from .beam files a=
re run natively if the VM supports JIT compilation.</div><div>=C2=A0</div><=
blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-l=
eft:1px solid rgb(204,204,204);padding-left:1ex"><div dir=3D"ltr"><div>(2) =
If I compile a module inside Erlang&#39;s shell, using the `c:c/1` function=
, is the module going to be compiled to native too? Will its execution be s=
witched to native?<br></div></div></blockquote><div><br></div><div>There is=
 no=C2=A0difference in how it is compiled, it will always be translated int=
o native code when loaded.</div><div>=C2=A0</div><blockquote class=3D"gmail=
_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204=
,204);padding-left:1ex"><div dir=3D"ltr"><div></div><div>(3) Where is store=
d the generated beamasm native code? I would like to get its size in bytes?=
<br></div></div></blockquote><div><br></div><div>It is stored in memory of =
the VM. You can get a file dump of the native code by passing `+JDdump true=
` when starting `erl`. There is no way to get the loaded memory size of a s=
ingle module, but you can get a relatively close value by checking what `er=
lang:memory(code)` returns before and after the module is loaded.</div><div=
>=C2=A0</div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px =
0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir=3D"=
ltr"><div><br></div><div>-- <br><div dir=3D"ltr"><span style=3D"font-family=
:&quot;trebuchet ms&quot;,sans-serif">Atenciosamente,<br>Vitor Rocha da Sil=
va</span><br></div></div></div>
</blockquote></div></div>
</blockquote></div><br clear=3D"all"><br>-- <br><div dir=3D"ltr"><span styl=
e=3D"font-family:&quot;trebuchet ms&quot;,sans-serif">Atenciosamente,<br>Vi=
tor Rocha da Silva</span><br></div>
</blockquote></div></div>

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