Re: [PATCH] mm: vmscan: fix missing psi annotation for node_reclaim()

[Shakeel Butt]

On Wed, Aug 18, 2021 at 8:26 AM Johannes Weiner <hannes@xxxxxxxxxxx> wrote:
>
> In a debugging session the other day, Rik noticed that node_reclaim()
> was missing memstall annotations. This means we'll miss pressure and
> lost productivity resulting from reclaim on an overloaded local NUMA
> node when vm.zone_reclaim_mode is enabled.
>
> There haven't been any reports, but that's likely because
> vm.zone_reclaim_mode hasn't been a commonly used feature recently, and
> the intersection between such setups and psi users is probably
> nil. Although, secondary memory such as CXL-connected DIMMS,
> persistent memory etc. and the page demotion patches that handle them
> (https://lore.kernel.org/lkml/20210401183216.443C4443@xxxxxxxxxxxxxxxxxx/)
> could soon make this a more common codepath again.
>
> Reported-by: Rik van Riel <riel@xxxxxxxxxxx>
> Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>

Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>