On Wed, May 01, 2024 at 10:26:13AM -0700, Shakeel Butt wrote: > At the moment, the amount of memory allocated for stats related structs > in the mem_cgroup corresponds to the size of enum node_stat_item. > However not all fields in enum node_stat_item have corresponding memcg > stats. So, let's use indirection mechanism similar to the one used for > memcg vmstats management. > > For a given x86_64 config, the size of stats with and without patch is: > > structs size in bytes w/o with > > struct lruvec_stats 1128 648 > struct lruvec_stats_percpu 752 432 > struct memcg_vmstats 1832 1352 > struct memcg_vmstats_percpu 1280 960 > > The memory savings is further compounded by the fact that these structs > are allocated for each cpu and for each node. To be precise, for each > memcg the memory saved would be: > > Memory saved = ((21 * 3 * NR_NODES) + (21 * 2 * NR_NODES * NR_CPUS) + > (21 * 3) + (21 * 2 * NR_CPUS)) * sizeof(long) > > Where 21 is the number of fields eliminated. > > Signed-off-by: Shakeel Butt <shakeel.butt@xxxxxxxxx> Reviewed-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
