On Tue, Jan 14, 2025 at 5:33 PM JP Kobryn <inwardvessel@xxxxxxxxx> wrote: > > Hi Michal, > > On 1/13/25 10:25 AM, Shakeel Butt wrote: > > On Wed, Jan 08, 2025 at 07:16:47PM +0100, Michal Koutný wrote: > >> Hello JP. > >> > >> On Mon, Dec 23, 2024 at 05:13:53PM -0800, JP Kobryn <inwardvessel@xxxxxxxxx> wrote: > >>> I've been experimenting with these changes to allow for separate > >>> updating/flushing of cgroup stats per-subsystem. > >> > >> Nice. > >> > >>> I reached a point where this started to feel stable in my local testing, so I > >>> wanted to share and get feedback on this approach. > >> > >> The split is not straight-forwardly an improvement -- > > > > The major improvement in my opinion is the performance isolation for > > stats readers i.e. cpu stats readers do not need to flush memory stats. > > > >> there's at least > >> higher memory footprint > > > > Yes this is indeed the case and JP, can you please give a ballmark on > > the memory overhead? > > Yes, the trade-off is using more memory to allow for separate trees. > With these patches the changes in allocated memory for the > cgroup_rstat_cpu instances and their associated locks are: > static > reduced by 58% > dynamic > increased by 344% > > The threefold increase on the dynamic side is attributed to now having 3 > rstat trees per cgroup (1 for base stats, 1 for memory, 1 for io), > instead of originally just 1. The number will change if more subsystems > start or stop using rstat in the future. Feel free to let me know if you > would like to see the detailed breakdown of these values. What is the absolute per-CPU memory usage?
