[Vm-dev] Re: Immutability, newspeak (was: Vm-dev post from jbaptiste.arnaud@gmail.com requires approval)

[John M McIntosh]

In my looking at performance issues like this the current generatios  
of CPUs just hide that extra instruction and the CPu runs a bit  
hotter. What should happen is some macrobenchmark be run with without  
the feature otherwise we are guessing

Sent from my iPhone

On 2010-06-09, at 10:25, Igor Stasenko <siguctua at gmail.com> wrote:

>
> On 8 June 2010 19:15, Andreas Raab <andreas.raab at gmx.de> wrote:
>>
>> On 6/8/2010 7:41 AM, David T. Lewis wrote:
>>>
>>> What do the VM developers think with respect adopting the VM  
>>> changes?
>>> The immutability bit is a scarce resource. Is it OK to allocate it
>>> for this purpose or are there likely to be other projects interested
>>> in using it for other reasons?
>>
>> Honestly, I don't thinnk the immutability bit carries its weight  
>> here.
>> There's some fun stuff you can do with it, for sure, but outside of
>> *extremely* specialized applications (oodbs) there will be little  
>> to no use
>> for it. At least I don't see where you'd make use of immutability  
>> in some
>> random app that's not a database. If it were essentially free to  
>> add it, I
>> wouldn't mind (like I said there's fun stuff that one can do) but  
>> given that
>> we're talking about allocating a header bit I feel that there's  
>> just not
>> enough mileage we get out of it...
>>
>> Just my random $.02.
>>
>
> my $.001
> my concern is not a header bit, but introduction of its check on each
> write operation,
> which will slow down things.
>
>> Cheers,
>>  - Andreas
>>
>
>
>
> -- 
> Best regards,
> Igor Stasenko AKA sig.