Re: [patch 0/9] mm: thrash detection-based file cache sizing v6

Andrew Morton
2013-11-26T00:57:33Z

On Sun, 24 Nov 2013 18:38:19 -0500 Johannes Weiner <hannes@cmpxchg.org> wrote:

> This series solves the problem by maintaining a history of pages
> evicted from the inactive list, enabling the VM to detect frequently
> used pages regardless of inactive list size and facilitate working set
> transitions.

It's a very readable patchset - thanks for taking the time to do that.

> 31 files changed, 1253 insertions(+), 401 deletions(-)

It's also a *ton* of stuff. More code complexity, larger kernel data
structures. All to address a quite narrow class of workloads on a
relatively small window of machine sizes. How on earth do we decide
whether it's worth doing?

Also, what's the memcg angle? This is presently a global thing - do
you think we're likely to want to make it per-memcg in the future?