On Fri, Apr 26, 2024 at 05:42:48PM -0700, Yosry Ahmed wrote: > On Fri, Apr 26, 2024 at 5:37 PM Shakeel Butt <shakeel.butt@xxxxxxxxx> wrote: > > > > mem_cgroup_events_index is a translation table to get the right index of > > the memcg relevant entry for the general vm_event_item. At the moment, > > it is defined as integer array. However on a typical system the max > > entry of vm_event_item (NR_VM_EVENT_ITEMS) is 113, so we don't need to > > use int as storage type of the array. For now just use int8_t as type > > and add a BUILD_BUG_ON() and will switch to short once NR_VM_EVENT_ITEMS > > touches 127. > > Any reason not to use uint8_t (or simply u8) and U8_MAX (instead of > the hardcoded 127)? > Just to keep the error check simple i.e. (index < 0). If we hit 127 then we can switch to uint8_t and S8_MAX as error. Though 127 should be replaced by S8_MAX. Somehow I was grep'ing for INT8*MAX variants. Anyways if there is more support for uint8_t, I will change otherwise I will keep as is.
