lkml.org 
[lkml]   [2004]   [Sep]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: 2.6.9-rc1: page_referenced_one() CPU consumption
Nikita Danilov wrote:

> I ran tests few times, and difference between patched and un-patched
> kernels is within noise, so you are right, try-lock does not help.
>

Well I'm glad - because I much prefer the spin_lock over the trylock :)

> But now I have new great idea instead. :)
>
> I think page_referenced() should transfer dirtiness to the struct page
> as it scans pte's. Basically the earlier we mark page dirty the better
> file system write-back performs, because page has more chances to be
> bulk-written by ->writepages(). This is better than my previous patches
> to this end (that used separate function to transfer dirtiness from
> pte's to the page), because
>
> - locking overhead is avoided
>
> - it's simpler.
>
> Nick, are you still in business of benchmarking random VM patches? :-)
>

Yeah I am, and I do have that patch sitting around. It can *really*
help for writeout via maped memory (obviously doesn't help write()).

I think Andrew's response was that it can theoretically cause writeout
for workloads that don't want it, so I should come up with at least
one real-world improvement!
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:06    [W:1.975 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site