Re: [Help-smalltalk] Big objects and GC

[Gwenael Casaccio]

On 05/10/2011 11:59 AM, Gwenael Casaccio wrote:
> Hi,
>
> Currently in GST big objects are allocated in the old space
> and won't move during the GC. The non-moving property is nice
> but putting big objects in the old space is not good since we
> need to do a full GC to free them.
>
> I've made a small patch not yet finished (there is one last bug when
> I do a make check) which creates a new kind of object:
>
> F_LARGE that can be in young space and after tenured to the old space.
> The difference is that the object won't move during the copy gc and the
> tenure step.
>
> git://github.com/MrGwen/GNU-Smalltalk.git in the branch LargeOOP.
>
> Cheers,
> Gwen

Hi,

Here is the patch, all the tests are green ;-)
Basically I've added a new flag F_LARGE, and a new method for allocating
large object: gst_alloc_large_obj. The object is fixed and won't move 
during the GC, so that implies that when tenuring an object I check if 
the object is F_LARGE. Also a special care is taken when the object is 
sweep, I use the correct heap. The image loading is updated to take care
of the F_LARGE field.

Cheers,
Gwen

large-oop.patch
Description: Text Data