Messages in this thread | | | Date | Fri, 28 Apr 2006 17:20:29 +1000 | From | Nick Piggin <> | Subject | Re: [PATCH] x86/PAE: Fix pte_clear for the >4GB RAM case |
| |
Andi Kleen wrote:
> No it was me who was confused sorry. Somehow i thought it was defined > away for !SMP > > (which would make sense because why would you want a compile barrier > for a barrier that is only needed on SMP?)
It is maybe not clearly named. smp_wmb() is a memory barrier to the regular (eg. RAM) cache coherency domain AFAICT. wmb() is also a barrier to io memory.
There is nothing to distinguish SMP and UP. I guess sometimes smp_ barriers would not even have to be a barrier() on UP, but other times they would have to be (eg. in the case of concurrent interrupts, context switches).
-- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |