lkml.org 
[lkml]   [2001]   [May]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: write drop behind effect on active scanning
On Wed, 23 May 2001, Marcelo Tosatti wrote:

> I just noticed a "bad" effect of write drop behind yesterday during some
> tests.
>
> The problem is that we deactivate written pages, thus making the inactive
> list become pretty big (full of unfreeable pages) under write intensive IO
> workloads.
>
> So what happens is that we don't do _any_ aging on the active list, and in
> the meantime the inactive list (which should have "easily" freeable
> pages) is full of locked pages.
>
> I'm going to fix this one by replacing "deactivate_page(page)" to
> "ClearPageReferenced(page)" in generic_file_write(). This way the written
> pages are aged faster but we avoid the bad effect just described.
>
> Any comments on the fix ?

1) I agree with it, drop-behind should make the pages we write
very likely for eviction, but we don't want that to stop the
eviction of other not-used pages ...

2) OTOH, if writeout of dirty pages is a problem for the system,
I guess we will want to fix that problem somehow ;)
(but that's another issue)

regards,

Rik
--
Linux MM bugzilla: http://linux-mm.org/bugzilla.shtml

Virtual memory is like a game you can't win;
However, without VM there's truly nothing to lose...

http://www.surriel.com/
http://www.conectiva.com/ http://distro.conectiva.com/

-
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 12:53    [W:0.038 / U:5.328 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site