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Re: [patch] Move loop structures to gc memory
Hello,
> > On 5/17/07, Mike Stump <mrs@apple.com> wrote:
> >> On May 16, 2007, at 5:47 PM, Ian Lance Taylor wrote:
> >> > Putting something in GC memory unnecessarily is inevitably slower than
> >> > not putting it in GC memory, if only because GC requires overhead to
> >> > track objects.
>
> >> But, the cost can be as cheap as:
>
> > It's not that cheap right now.
> > Unless you are going to make it this cheap, can we please stop
> > pretending it's this cheap?
>
> This argument seems backwards.
>
> If our GC memory allocator is slow, this affects *every* call of
> ggc_alloc.
>
> Moving objects out of the GC pool because ggc_alloc is slow is a
> local, limited fix, that merely papers over the real problem.
no, it is a proper fix -- it makes us avoid using GC for purposes for
that it is not suitable.
Of course, making GC faster is not a bad idea, but using GC for objects
for that you know exactly the lifetime and the expected usage pattern
at best wastes this extra information you have.
Zdenek