Re: [SLUG] Multithreading vs. Forks

[Ken Foskey <foskey@xxxxxxxxxxxxxxxx>]

Andrew Bennetts wrote:

> I was under the impression that a different thread *is* a different
> context... it has its own stack, its own registers, and probably can
> have its own memory address space too.  They're basically like
> processes, except they tend to share an awful lot of their memory with
> other threads of the same "process".
>
> In this case, I fail to see why it would be significantly faster to
> switch between threads than it is to switch between processes.  I should
> probably write a program to benchmark this to find out for certain, I
> suppose.
Threads do not have to reload the total program vtable,  each copy of 
the thread runs in the same address space and therefore it does not need 
to switch address spaces,  it is entirely possible that different 
programs will generate more page faults due to duplicated memory 
structures that are not really required, for example those startup 
parameters.

KenF