Re: [PATCH] A new entry for /proc

[Mauricio Lin <mauriciolin@gmail.com>]

Well,

It is working better now. You are right Hugh. Now the new version is
faster than the old one. I removed the struct page and its related
function.

Thanks,

BR,

Mauricio Lin.

On Tue, 1 Mar 2005 04:08:15 -0400, Mauricio Lin <mauriciolin@gmail.com> wrote:
> On Mon, 28 Feb 2005 20:41:31 +0000 (GMT), Hugh Dickins <hugh@veritas.com> wrote:
> > On Mon, 28 Feb 2005, Mauricio Lin wrote:
> > >
> > > Now I am testing with /proc/pid/smaps and the values are showing that
> > > the old one is faster than the new one. So I will keep using the old
> > > smaps version.
> >
> > Sorry, I don't have time for more than the briefest look.
> >
> > It appears that your old resident_mem_size method is just checking
> > pte_present, whereas your new smaps_pte_range method is also doing
> > pte_page (yet no prior check for pfn_valid: wrong) and checking
> > !PageReserved i.e. accessing the struct page corresponding to each
> > pte.  So it's not a fair comparison, your new method is accessing
> > many more cachelines than your old method.
> >
> > Though it's correct to check pfn_valid and !PageReserved to get the
> > same total rss as would be reported elsewhere, I'd suggest that it's
> > really not worth the overhead of those struct page accesses: just
> > stick with the pte_present test.
> So, I can remove the PageReserved macro without no problems, right?
> 
> 
> >
> > Your smaps_pte_range is missing pte_unmap?
> Yes, but I already fixed this problem.  Paul Mundt has checked the
> unmap missing.
> 
> Thanks,
> 
> Let me perform new experiments now.
> 
> BR,
> 
> Mauricio Lin.
>