On Tue 18-06-19 12:59:24, Waiman Long wrote: > On 6/18/19 8:37 AM, Michal Hocko wrote: [...] > > Is this useful enough to put into slabinfo? Doesn't this sound more like > > a debugfs kinda a thing? > > I guess it is probably more on the debug side of things. I add it to > slabinfo as the data is readily available. It will be much more work if > we need to export the data via debugfs. > > We are seeing the kmem_cache slab growing continuously overtime when > running a container-based workloads. Roman's kmem_cache reparenting > patch will hopefully solve a major part of the problem, but we still > need a way to confirm that by looking at how many memcg kmem_caches are > associated with each root kmem_cache. I am not disputing usefulness. Dead memcgs are showing up as a problem for a longer time and having a more debugging information is definitely useful. I am just not really sure that /proc/slabinfo is the proper vehicle for that information. It might be just easier to stick it there but that is not the best justification for adding something we will have to maintain for ever. Not to mention that the number of dead memcgs might not be enough to debug further when we can easily end up needing to provide more in something less "carved in stone" kinda interface like debugfs. -- Michal Hocko SUSE Labs
