Re: [PATCH] simple euristic for further free packing improvements

> Nicolas Pitre <nico@cam.org> writes:
> 
> > @@ -1038,8 +1038,8 @@ static int try_delta(struct unpacked *tr
> >  
> >  	/* Now some size filtering euristics. */
> >  	size = trg_entry->size;
> > -	max_size = size / 2 - 20;
> > -	if (trg_entry->delta)
> > +	max_size = (size/2 - 20) / (src_entry->depth + 1);
> > +	if (trg_entry->delta && trg_entry->delta_size <= max_size)
> >  		max_size = trg_entry->delta_size-1;
> >  	src_size = src_entry->size;
> >  	sizediff = src_size < size ? size - src_size : 0;
> 
> At the first glance, this seems rather too agressive.  It makes
> me wonder if it is a good balance to penalize the second
> generation base by requiring it to produce a small delta that is
> at most half as we normally would (and the third generation a
> third), or maybe the penalty should kick in more gradually, like
> e.g. ((max_depth * 2 - src_entry->depth) / (max_depth * 2).
> 
> Having said that, judging from your past patches, I learned to
> trust that you have tried tweaking this part and settled on this
> simplicity and elegance, so I'll take the patch as is -- if
> somebody wants to play with it that can always be done to
> further improve things.