Subj : Re: CMPXCHG timing
To   : comp.programming.threads
From : Michael Pryhodko
Date : Fri Apr 01 2005 03:45 pm

> These two assumptions don't hold for x86, and shouldn't be guaranteed
to
> hold because they would prevent *many* important optimizations
(really,
> not just theoretically).

Ok. Situation:
- two processors have empy store buffers
- two processor were executing similar code for some time (i.e.
pipeline state should be similar)
- now they execute:
mov mem_addr, value
sfence

For me it is quite logical that they should spend the same amount of
clocks  for this operation (suppose that flushing store buffer takes
the same time  regardless of mem_addr). I understand that this is only
my assumptions.

But on other hand you did not provide any proof of your poion. ;)

Bye.
Sincerely yours, Michael.

.