Re: [PATCH 10/27] mm, vmscan: Clear congestion, dirty and need for compaction on a per-node basis

Mel Gorman
2016-06-16T10:29:11Z

On Thu, Jun 16, 2016 at 11:29:00AM +0200, Vlastimil Babka wrote:
> On 06/09/2016 08:04 PM, Mel Gorman wrote:
> >Congested and dirty tracking of a node and whether reclaim should stall
> >is still based on zone activity. This patch considers whether the kernel
> >should stall based on node-based reclaim activity.
>
> I'm a bit confused about the description vs actual code.
> It appears to move some duplicated code to a related function, which is
> fine. The rest of callsites that didn't perform the clearing before
> (prepare_kswapd_sleep() and wakeup_kswapd()) might be a bit overkill, but
> won't hurt. But I don't see the part "considers whether the kernel
> should stall based on node-based reclaim activity". Is something missing?
>

Tired when writing the changelog. Does this make more sense?

mm, vmscan: Remove duplicate logic clearing node congestion and dirty state

Reclaim may stall if there is too much dirty or congested data on a node.
This was previously based on zone flags and the logic for clearing the
flags is in two places. As congestion/dirty tracking is now tracked on
a per-node basis, we can remove some duplicate logic.

--
Mel Gorman
SUSE Labs