On Tue, Jul 03, 2018 at 12:19:35PM -0700, Shakeel Butt wrote: > On Tue, Jul 3, 2018 at 12:13 PM Kirill Tkhai <ktkhai@xxxxxxxxxxxxx> wrote: > > > Do we really have so very many !memcg-aware shrinkers? > > > > > > $ git grep -w register_shrinker |wc > > > 32 119 2221 > > > $ git grep -w register_shrinker_prepared |wc > > > 4 13 268 > > > (that's an overstatement; one of those is the declaration, one the definition, > > > and one an internal call, so we actually only have one caller of _prepared). > > > > > > So it looks to me like your average system has one shrinker per > > > filesystem, one per graphics card, one per raid5 device, and a few > > > miscellaneous. I'd be shocked if anybody had more than 100 shrinkers > > > registered on their laptop. > > > > > > I think we should err on the side of simiplicity and just have one IDR for > > > every shrinker instead of playing games to solve a theoretical problem. > > > > It just a standard situation for the systems with many containers. Every mount > > introduce a new shrinker to the system, so it's easy to see a system with > > 100 or ever 1000 shrinkers. AFAIR, Shakeel said he also has the similar > > configurations. > > > > I can say on our production systems, a couple thousand shrinkers is normal. But how many are !memcg aware? It sounds to me like almost all of the shrinkers come through the sget_userns() caller, so the other shrinkers are almost irrelevant.
