On Mon 22-08-22 11:37:30, Roman Gushchin wrote: [...] > I wonder only if we want to make it configurable (Idk a sysctl or maybe > a config option) and close the topic. I do not think this is a good idea. We have other examples where we have outsourced internal tunning to the userspace and it has mostly proven impractical and long term more problematic than useful (e.g. lowmem_reserve_ratio, percpu_pagelist_high_fraction, swappiness just to name some that come to my mind). I have seen more often these to be used incorrectly than useful. In this case, I guess we should consider either moving to per memcg charge batching and see whether the pcp overhead x memcg_count is worth that or some automagic tuning of the batch size depending on how effectively the batch is used. Certainly a lot of room for experimenting. -- Michal Hocko SUSE Labs
