Re: page table lock patch V15 [0/7]: overview

[Roman Zippel]

Hi,

On Fri, 14 Jan 2005, Andi Kleen wrote:

> > But there might be a loss in the UP case. Spinlocks are optimized away, 
> > but your cmpxchg emulation enables/disables interrupts with every access.
> 
> Only for 386s and STI/CLI is quite cheap there.

But it's still not free and what about other archs? Why not just check 
__HAVE_ARCH_CMPXCHG and provide a replacement, which is guaranteed cheaper 
if no interrupt synchronisation is needed. 

bye, Roman
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/