Re: [RFC 2/2] page_frag_cache: Store metadata in struct page

Eric Dumazet
2018-03-16T21:32:24Z

On 03/16/2018 02:05 PM, Matthew Wilcox wrote:

>
> Obviously if the problem turns out to be the cacheline thrashing rather
> than the call to page_to_virt, then this is pointless to test.
>
>> I won't be able to test the patches until next week, but I expect I
>> will probably see a noticeable regression when performing a small
>> packet routing test.
>
> I really appreciate you being willing to try this for me. I need to
> get myself a dual-socket machine to test things like this.
>

It seems my prior mail/answer was lost.

Issue is cacheline thrashing indeed, particularly on PowerPC (64 KB pages)