On 01/18/2016 11:50 AM, Paul Eggert wrote:
> John Wiegley wrote:
>> Can you elaborate what unexec has been doing for us up till now, and what
>> living without it will entail in terms of both technical content and work
>> required?
> 
> unexec lets Emacs save much of its internal state into an executable
> that will start more quickly than an Emacs that needs to regenerate that
> internal state from source files. Originally, unexec also made the
> internal-state read-only, which helped performance significantly long
> ago; nowadays the performance is no longer worth the porting hassle so
> Emacs no longer does that.

Emacs does go to a lot of trouble to avoid taking COW faults on
purespace objects though.