Re: Page fault scalability patch V18: Drop first acquisition of ptl

Andrew Morton
2005-03-03T06:20:08Z

Christoph Lameter <clameter@sgi.com> wrote:
>
> On Wed, 2 Mar 2005, Andrew Morton wrote:
>
> > > Any mmap changes requires the mmapsem.
> >
> > sys_remap_file_pages() will call install_page() under down_read(mmap_sem).
> > It relies upon page_table_lock for pte atomicity.
>
> This is not relevant since it only deals with file pages.

OK. And CONFIG_DEBUG_PAGEALLOC?

> ptes are only
> installed atomically for anonymous memory (if CONFIG_ATOMIC_OPS
> is defined).

It's a shame. A *nice* solution to this problem would address all pte ops
and wouldn't have such special cases...