Re: Fwd: Re: slablru for 2.5.32-mm1

[Andrew Morton <akpm@zip.com.au>]

Ed Tomlinson wrote:
> 
> ...
> The pages which back slab objects may be manually marked as referenced
> via kmem_touch_page(), which simply sets PG_referenced.  It _could_ use
> mark_page_accessed(), but doesn't.  So slab pages will always remain on
> the inactive list.
> 
> --
> Since shrinking a slab is a much lower cost operation than a swap we keep
> the slab pages in inactive where they age faster.  Note I did test with slabs
> following the normal active/inactive cycle - we swapped more.
> --

It worries me that we may be keeping a large number of unfreeable
slab pages on the inactive list.  These will churn around creating 
extra work, but more significantly they will revent refill_inactive
from bringing down really-reclaimable pages.
 
> ...
> Actually the BUG_ON conversion were done by Craig Kulesa.   It would be a
> good idea to credit him with the initial port to 2.5 - he did to the work.

OK.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/