On Wed, Apr 07, 2021 at 01:07:27PM +0300, Kirill Tkhai wrote: > > Here is how the calculation turns out to be in my setup: > > > > Number of possible NUMA nodes = 2 > > Number of mounts per container = 7 (Check below to see which are these) > > Number of list creation requests per mount = 2 > > Number of containers = 10000 > > memcg_nr_cache_ids for 10k containers = 12286 > > Luckily, we have "+1" in memcg_nr_cache_ids formula: size = 2 * (id + 1). > In case of we only multiplied it, you would have to had memcg_nr_cache_ids=20000. Not really, it would grow like this for size = 2 * id id 0 size 4 id 4 size 8 id 8 size 16 id 16 size 32 id 32 size 64 id 64 size 128 id 128 size 256 id 256 size 512 id 512 size 1024 id 1024 size 2048 id 2048 size 4096 id 4096 size 8192 id 8192 size 16384 Currently (size = 2 * (id + 1)), it grows like this: id 0 size 4 id 4 size 10 id 10 size 22 id 22 size 46 id 46 size 94 id 94 size 190 id 190 size 382 id 382 size 766 id 766 size 1534 id 1534 size 3070 id 3070 size 6142 id 6142 size 12286 > > Maybe, we need change that formula to increase memcg_nr_cache_ids more accurate > for further growths of containers number. Say, > > size = id < 2000 ? 2 * (id + 1) : id + 2000 For the above, it would only be marginally better like this: id 0 size 4 id 4 size 10 id 10 size 22 id 22 size 46 id 46 size 94 id 94 size 190 id 190 size 382 id 382 size 766 id 766 size 1534 id 1534 size 3070 id 3070 size 5070 id 5070 size 7070 id 7070 size 9070 id 9070 size 11070 All the above numbers are for 10k memcgs. Regards, Bharata.
