Hi!

> > Ah, I overlooked the implementation. What we care is to only run mmx if
> > there is no FPU data to clobber (but we can run mmx even if the current
> > task used math in some previous timeslice). So the right implementation
> > should be this according to me:
> > 
> > 	if (!(current->flags & PF_USEDFPU))
> > 		checksum_mmx();
> > 	else
> > 		checksum_nommx();
> 
> Wont this have cache trashing problems?

I really don't think so -- if you have done taskswitch from/to
different task, your caches are probably lost anyways. [And -- we've
only increased cache footprint twice. If cache is so big it can hold
task switching routine, it is probably big enough for two copies of
packet checksummer.]

								Pavel
-- 
I'm really pavel@ucw.cz. Look at http://195.113.31.123/~pavel.  Pavel
Hi! I'm a .signature virus! Copy me into your ~/.signature, please!

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/