Unnecessary cache-line flush on page table updates ?

[Catalin Marinas]

On Fri, Jul 01, 2011 at 10:42:00PM +0100, heechul Yun wrote:
> Great.
> 
> Removing the PTE flush seems to have a noticeable performance
> difference in my test. The followings are lmbench 3.0a performance
> result measured on a Cortex A9 SMP platform. So far, I did not have
> any problem while doing various test.
> 
> =========
> mm-patch:
> =========
> Pagefaults on /tmp/XXX: 3.0759 microseconds
> Process fork+exit: 464.5414 microseconds
> Process fork+execve: 785.4944 microseconds
> Process fork+/bin/sh -c: 488.6204 microseconds
> 
> =========
> original:
> =========
> Pagefaults on /tmp/XXX: 3.6209 microseconds
> Process fork+exit: 485.5236 microseconds
> Process fork+execve: 820.0613 microseconds
> Process fork+/bin/sh -c: 2966.3828 microseconds

Given these results, I think it's worth merging the patch. Can I add
your Tested-by?

I think there can be a few other optimisations in the TLB area but it
needs some digging.

Thanks.

-- 
Catalin