Re: [PATCH -mm] remove swap token code

From: KOSAKI Motohiro
Date: Wed Apr 11 2012 - 14:10:13 EST


(4/10/12 9:48 PM), Johannes Weiner wrote:
On Mon, Apr 09, 2012 at 11:32:01AM -0400, Rik van Riel wrote:
The swap token code no longer fits in with the current VM model.
It does not play well with cgroups or the better NUMA placement
code in development, since we have only one swap token globally.

It also has the potential to mess with scalability of the system,
by increasing the number of non-reclaimable pages on the active
and inactive anon LRU lists.

Last but not least, the swap token code has been broken for a
year without complaints. This suggests we no longer have much
use for it.

The days of sub-1G memory systems with heavy use of swap are
over. If we ever need thrashing reducing code in the future,
we will have to implement something that does scale.

Signed-off-by: Rik van Riel<riel@xxxxxxxxxx>

Acked-by: Johannes Weiner<hannes@xxxxxxxxxxx>

Acked-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>

I really think swap token is sane. but now (after merging Johannes's memcg naturalization)
it don't work and we don't have a reason to maintain _current_ implementaion.



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