Re: [PATCH] provide means to access the zone from the correspondingchunk

[Paolo polimi <bonzini at gnu dot org>]

Daniel Berlin wrote:

> On May 7, 2004, at 9:59 AM, Paolo Bonzini wrote:
>
> > This patch enables the zone collector to recover the page_entry and
> > alloc_zone structures from the address of an arbitrary ggc_alloc-ed 
> > pointer.  Unfortunately, while very useful, this is quite invasive.
>
>
> Why do we need to do this?
> What exactly useful property does being able to get the page entry have?

It allows to recover the zone from the chunk, without *any* kind of 
overhead.  For example, it allows to track inter-zone pointers or chunks 
that live in the garbage_zone.

I agree it may not be worth spending four bytes per chunk, but at zero 
cost...

Paolo