[erlang-questions] Erlang Memory Question

[Eranga Udesh]

Thanks for the information received so far.

Wouldn't it be good for Erlang to have a single object garbage collection
function/bif? For example, when I no longer require a large object, I force
to garbage collect it, without making a full sweep?

As mentioned in the document, a full sweep may degrade the performance.

- Eranga

On Tue, Sep 23, 2014 at 12:10 AM, Björn-Egil Dahlberg <
wallentin.dahlberg@REDACTED> wrote:

> It should suffice by running an erlang:garbage_collect/0 directly after
> extracting some parts of the structure:
>
> function1() ->
>
> X1 = ... fetch a large object ....
>
> ... some processing...
>
> X2 = ... extract a part of X1 ...
> erlang:garbage_collect(),
> ... long running job....
>
>
> As long as the object of X1 is not referenced by the process after the
> explicit call to the gc, you're fine.
> Note also, an explicit call to garbage_collect/0 will always to a
> 'fullsweep'.
>
> Ofc, as Jesper mentioned, the it's probably preferable not to fetch the
> whole object if possible.
>
> // Björn-Egil
>
>
> 2014-09-22 19:56 GMT+02:00 Jesper Louis Andersen <
> jesper.louis.andersen@REDACTED>:
>
>> In general: No it won't. GC will trigger once the process has allocated
>> enough data. If your processing is allocating enough data, this will
>> quickly happen and you don't have to worry. If not, you may have to gently
>> persuade the process to do so. There are several ways:
>>
>> * Set fullsweep_after on the process with a low value (0) and run
>> erlang:garbage_collect()
>> * Go through a hibernation with an immediate wakeup (feels ugly to me)
>> * Handle fetching and extraction in a separate process and send the
>> extracted part 'x' back as a message. This will free up memory almost
>> immediately for other processes to use (simple and elegant)
>> * Don't fetch the large object in the first place, but make it possible
>> to ask for an extraction only. Or stream data a bit at a time and handle
>> the stream in chunks rather than everything at once.
>>
>>
>> On Mon, Sep 22, 2014 at 4:11 PM, Eranga Udesh <eranga.erl@REDACTED>
>> wrote:
>>
>>> Hi,
>>>
>>> I'm trying to optimize my memory consumption in Erlang VM and to garbage
>>> collect as soon as possible.
>>>
>>> Let's say I have a large object, "X", After some processing, I only need
>>> to work on small part of X, called "x".
>>>
>>> Can someone advice me if below process flow will put the large object X
>>> in to garbage collection, while waiting for the long running job to
>>> continue?
>>>
>>> function1() ->
>>>
>>> X = ... fetch a large object....
>>>
>>> ... some processing...
>>>
>>> x = ... extract a part of X...
>>> ... long running job....
>>>
>>>
>>> If it's not putting X into garbage collection, does below change do that?
>>>
>>> function1() ->
>>>
>>> X = ... fetch a large object....
>>>
>>> ... some processing...
>>>
>>> x = ... extract a part of X...
>>> function2(x).
>>>
>>> function2(x) ->
>>>
>>> ... long running job...
>>>
>>>
>>> Tks,
>>> - Eranga
>>>
>>> _______________________________________________
>>> erlang-questions mailing list
>>> erlang-questions@REDACTED
>>> http://erlang.org/mailman/listinfo/erlang-questions
>>>
>>>
>>
>>
>> --
>> J.
>>
>> _______________________________________________
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>> http://erlang.org/mailman/listinfo/erlang-questions
>>
>>
>
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