On Wed, Sep 07, 2022 at 04:35:37AM +0000, Shakeel Butt wrote: > The struct memcg_vmstats and struct memcg_vmstats_percpu contains two > arrays each for events of size NR_VM_EVENT_ITEMS which can be as large > as 110. However the memcg v1 only uses 4 of those while memcg v2 uses > 15. The union of both is 17. On a 64 bit system, we are wasting > approximately ((110 - 17) * 8 * 2) * (nr_cpus + 1) bytes which is > significant on large machines. > > This patch reduces the size of the given structures by adding one > indirection and only stores array of events which are actually used by > the memcg code. With this patch, the size of memcg_vmstats has reduced > from 2544 bytes to 1056 bytes while the size of memcg_vmstats_percpu has > reduced from 2568 bytes to 1080 bytes. This is pretty impressive! Thank you, Shakeel! Acked-by: Roman Gushchin <roman.gushchin@xxxxxxxxx> for the series. Thanks!
