Re: [Help-smalltalk] Read-only oldspace

[Gwenael Casaccio]

On 05/13/2011 04:32 PM, Gwenael Casaccio wrote:
> On 05/13/2011 08:46 AM, Paolo Bonzini wrote:
> > On 05/12/2011 05:24 PM, Holger Hans Peter Freyther wrote:
> > > How many read-only objects do we have in a bootstrapped image? In a
> > > typical
> > > iliad application? Does it make sense to optimize for it? or will RO
> > > handling
> > > just become more easy and this is a cleanup?
> >
> > I think the point is to optimize _non_ read-only objects at the cost of
> > making tenuring read-only objects a bit more expensive (you will have to
> > unprotect the page, allocate, copy, protect the page). We also win
> > read-only access to fixed instance variables, which GNU Smalltalk
> > doesn't have (only indexed instance variables are protected).
> >
> > BTW, for the same reason I think that moving objects to read-only space
> > directly when you make them read-only (like you did for fixedspace) is a
> > good idea. Anyway, read-only objects are mostly literals so they are
> > long-living. Gwen, can you reorganize the patch along these lines?
> >
> > The patch making readonly space, well, readonly should be a separate
> > one. For unprotection/protection around allocation you can add hooks to
> > alloc.c heaps, like we have after_allocating: that would be
> > before_freeing, after_freeing, before_allocating.
> >
> > Paolo
>
> I've made the new patch, the ro_old space is like fixed. I've fixed
> two bugs one in the symbol allocation and another when the ro_old heap
> should grow.
>
> Gwen

Hi,

Paolo can you check the patch, here I've changed a bit the behavior of 
make_ro; I preserve F_FIXED, F_OLD, or young information thus when 
making an object writable I can restore it in the good space.
It seems to be the definitive version

Gwen

ro-space-for-paolo.patch
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