Re: [PATCH 5/6] KVM: Separate rmap_pde from kvm_lpage_info->write_count

[Xiao Guangrong]

On 06/29/2012 01:39 AM, Avi Kivity wrote:

> But I still think it's the right thing since it simplifies the code.
> Maybe we should add a prefetch() on write_count do mitigate the
> overhead, if it starts showing up in profiles.
> 

Long time ago, there was a discussion about dropping prefetch in the
operation of list walking:
	http://lwn.net/Articles/444336/
IIRC, the conclusion is that it is better to let CPU prefetch memory
by itself.

Actually, when i developed lockless spte walking, i measure the performance if
prefetch was used, but i did not see the improvement.


--
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/