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From Akash Ashok <thehellma...@gmail.com>
Subject Re: Memory Deallocation Issue
Date Thu, 20 Oct 2011 09:02:38 GMT
On Thu, Oct 20, 2011 at 2:13 PM, Ashish <paliwalashish@gmail.com> wrote:

> On Thu, Oct 20, 2011 at 1:57 PM, Raffaele P. Guidi
> <raffaele.p.guidi@gmail.com> wrote:
> > Gooood news! As with every not-so-well documented piece of software I
> should
> > have read the code before taking wrong assumptions (or at least take a
> look
> > at stackoverflow ;) ). I think we should ask our mentors to assign
> developer
> > rights. Or is it to be filed to INFRA? Sorry, I'm still an ASF rookie ;)
> >
> > Thanks,
> >    Raffaele
>
> I again have to disagree on this feature. Why would you need to have
> to deallocate memory? You should know how much you need.
> Its always better to have a contiguous memory allocated. It works
> well. Dynamically resizing will pose challenges and add to performance
> issues.
>
> From cache perspective, we are anyways clearing the element, making
> way for new element.
>
> IMHO, I see offheap as a big chunk of memory which is pre-allocated
> and the MemoryManager we have written should deal with all the object
> management. We can manage memory as chunks or realize maps in native
> memory, is all upto the design we choose.
>
> This is very much an importand feature I believe. Assume in production you
made the
wrong decision of how much memory was pre-allocated, then you shouldn't be
charged
with the penalty of being unable to use that memory right ? Even though this
is very expensive
the feature should be available but documented well enough, warning against
its use.

If you are concerned about memory fragmentation, It wouldn't lead to a lot
of fragmentaion
if we deallocate and re allocate contiguous blocks right. I am under the
 assumption that
 allocateDirect allocates contiguous blocks of memory.


@ashok - You don't need dev access to submit patches. Create a JIRA
> account and submit patches. New committers @ASF are voted by PMC based
> on their contribution :)
>
> I never asked to add me as a committer :) I asked for contributor access
where in
I have the permission to assign a ticket to myself and SubmitPatch option on
JIRA.
On HBase only after I was added as a contributor I got these options. This
was the
rationale behind my request.

Cheers,
Akash A


> thanks
> ashish
>

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