RE: [PATCH 2.5.52] Use __set_current_state() instead of current->

[Alan Cox]

On Thu, 2002-12-19 at 19:04, Perez-Gonzalez, Inaky wrote:
> 
> > > And that would now really work when CONFIG_X86_OOSTORE=1 is required
> > > [after all, it is a write, so it'd need the equivalent of a wmb() or
> > > xchg()].
> > 
> > Is this a hint that your employer may have an x86 chip in the future
> > with weak ordering? :)
> 
> Hmmm ... taking into account that there are some many thousands of
> employees in my company and that I know less than one hundred ...
> and that they are all software ... well, I don't think I am into
> the rumour mill :]

Also OOSTORE is there because other vendors already make weak store
order capable x86 processors. One example of this is the Winchip - where
turning off strict store ordering is worth 30% performance.

In addition you have to treat store ordering/locking carefully due to
the pentium pro store fencing errata. (Thats why our < PII kernel
generates lock movb to unlock when in theory the lock isnt needed).

Alan