Re: [PATCH 3/6] mm: page_alloc: move free pages when converting block during isolation

[Mel Gorman]

On Mon, Sep 11, 2023 at 03:41:44PM -0400, Johannes Weiner wrote:
> When claiming a block during compaction isolation, move any remaining
> free pages to the correct freelists as well, instead of stranding them
> on the wrong list. Otherwise, this encourages incompatible page mixing
> down the line, and thus long-term fragmentation.
> 
> Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>

Hmm, this is potentially expensive in some cases but it's also correct.
Given how expensive the whole path is, I doubt it's noticable and some of
this activity will be !direct_compaction anyway and relatively invisible
even if I'm not a fan of hiding overhead in kthreads. Either way;

Acked-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>

-- 
Mel Gorman
SUSE Labs