Re: [PATCH 3/9] kstaled: page_referenced_kstaled() and supporting infrastructure.

KAMEZAWA Hiroyuki
2011-09-28T07:18:56Z

On Tue, 27 Sep 2011 17:49:01 -0700
Michel Lespinasse <walken@google.com> wrote:

> Add a new page_referenced_kstaled() interface. The desired behavior
> is that page_referenced() returns page references since the last
> page_referenced() call, and page_referenced_kstaled() returns page
> references since the last page_referenced_kstaled() call, but they
> are both independent of each other and do not influence each other.
>
> The following events are counted as kstaled page references:
> - CPU data access to the page (as noticed through pte_young());
> - mark_page_accessed() calls;
> - page being freed / reallocated.
>
>
> Signed-off-by: Michel Lespinasse <walken@google.com>

Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

2 questions.

What happens at Transparent HugeTLB pages are splitted/collapsed ?
Does this feature can ignore page migration i.e. flags should not be copied ?

Thanks,
-Kame