Re: [PATCH 07/34] mm, vmscan: make kswapd reclaim in terms of nodes
From: Srikar Dronamraju
Date: Wed Aug 31 2016 - 02:10:36 EST
> > The trigger is memblock_reserve() for the complete node memory. And
> > this is exactly what FA_DUMP does. Here again the node has memory but
> > its all reserved so there is no free memory in the node.
> > Did you mean populated_zone() when you said zone_populated or have I
> > mistaken? populated_zone() does return 1 since it checks for
> > zone->present_pages.
> Yes, I meant populated_zone(). Using present pages may have hidden
> a long-lived corner case as it was unexpected that an entire node
> would be reserved. The old code happened to survive *probably* because
> pgdat_reclaimable would look false and kswapd checks for pgdat being
> balanced would happen to do the right thing in this case.
> Can you check if something like this works?
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index d572b78b65e1..cf64a5456cf6 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -830,7 +830,7 @@ unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
> static inline int populated_zone(struct zone *zone)
> - return (!!zone->present_pages);
> + return (!!zone->managed_pages);
> extern int movable_zone;
This indeed fixes the problem.
Please add my
Tested-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>