Re: page fault scalability patch V12 [0/7]: Overview and performance

Hugh Dickins
2004-12-11T00:44:38Z

On Fri, 10 Dec 2004, Andrew Morton wrote:
> Hugh Dickins <hugh@veritas.com> wrote:
> > But why is do_anonymous_page adding anything to lru_cache_add_active,
> > when its other callers leave it at that? What's special about the
> > do_anonymous_page case?
>
> do_swap_page() is effectively doing the same as do_anonymous_page().
> do_wp_page() and do_no_page() appear to be errant.

Demur. do_swap_page has to mark_page_accessed because the page from
the swap cache is already on the LRU, and for who knows how long.
The others (and count in fs/exec.c's install_arg_page) are dealing
with a freshly allocated page they are putting onto the active LRU.

My inclination would be simply to remove the mark_page_accessed
from do_anonymous_page; but I have no numbers to back that hunch.

Hugh