Re: [PATCH v14 04/15] mm/damon: Adaptively adjust regions

From: Leonard Foerster
Date: Wed Jun 03 2020 - 04:22:30 EST

On 2020-06-02T15:01:14+02:00 SeongJae Park <sjpark@xxxxxxxxxx> wrote:

> From: SeongJae Park <sjpark@xxxxxxxxx>
> At the beginning of the monitoring, DAMON constructs the initial regions
> by evenly splitting the memory mapped address space of the process into
> the user-specified minimal number of regions. In this initial state,
> the assumption of the regions (pages in same region have similar access
> frequencies) is normally not kept and thus the monitoring quality could
> be low. To keep the assumption as much as possible, DAMON adaptively
> merges and splits each region.
> For each ``aggregation interval``, it compares the access frequencies of
> adjacent regions and merges those if the frequency difference is small.
> Then, after it reports and clears the aggregated access frequency of
> each region, it splits each region into two regions if the total number
> of regions is smaller than the half of the user-specified maximum number
> of regions.
> In this way, DAMON provides its best-effort quality and minimal overhead
> while keeping the bounds users set for their trade-off.
> Signed-off-by: SeongJae Park <sjpark@xxxxxxxxx>

Reviewed-by: Leonard Foerster <foersleo@xxxxxxxxx>