On Wed 08-03-17 15:41:59, Michal Hocko wrote: > On Fri 03-03-17 14:53:07, David Rientjes wrote: > > Initscripts can use the information (protection levels) from > > /proc/zoneinfo to configure vm.lowmem_reserve_ratio at boot. > > > > vm.lowmem_reserve_ratio is an array of ratios for each configured zone on > > the system. If a zone is not populated on an arch, /proc/zoneinfo > > suppresses its output. > > > > This results in there not being a 1:1 mapping between the set of zones > > emitted by /proc/zoneinfo and the zones configured by > > vm.lowmem_reserve_ratio. > > > > This patch shows statistics for non-populated zones in /proc/zoneinfo. > > The zones exist and hold a spot in the vm.lowmem_reserve_ratio array. > > Without this patch, it is not possible to determine which index in the > > array controls which zone if one or more zones on the system are not > > populated. > > > > Remaining users of walk_zones_in_node() are unchanged. Files such as > > /proc/pagetypeinfo require certain zone data to be initialized properly > > for display, which is not done for unpopulated zones. > > Does it really make sense to print any counters of that zone though? > Your follow up patch just suggests that we don't want some but what > about others? > > I can see how skipping empty zones completely can be clumsy but wouldn't > it be sufficient to just provide > > Node $NUM, zone $NAME > (unpopulated) > > instead?
ping -- Michal Hocko SUSE Labs
