[racket-dev] gc vs assignment

On 08/24/2010 11:38 AM, Jay McCarthy wrote:
> On Tue, Aug 24, 2010 at 10:53 AM, Joe Marshall<jmarshall at alum.mit.edu>  wrote:
>    
>> I'm surprised that racket3m uses page protection.  Taking a hardware trap
>> can often be thousands of times slower than taking an inline conditional
>> branch.
>>      
> My understanding is that 3m does this because it is doing exact
> garbage-collection on the C code rather than just on the Racket. I
> presume that it would be hard (and useful) engineering to make it GC
> more traditionally.
>
> Jay
>
>    
Right.
To use more traditional write barriers, xform would need to become a lot 
smarter, inserting write barriers at assignments in the c code.