On Thu 16-11-17 21:48:05, Byungchul Park wrote: > On 11/16/2017 9:02 PM, Michal Hocko wrote: > > for each struct page. So you are doubling the size. Who is going to > > enable this config option? You are moving this to page_ext in a later > > patch which is a good step but it doesn't go far enough because this > > still consumes those resources. Is there any problem to make this > > kernel command line controllable? Something we do for page_owner for > > example? > > Sure. I will add it. > > > Also it would be really great if you could give us some measures about > > the runtime overhead. I do not expect it to be very large but this is > > The major overhead would come from the amount of additional memory > consumption for 'lockdep_map's. yes > Do you want me to measure the overhead by the additional memory > consumption? > > Or do you expect another overhead? I would be also interested how much impact this has on performance. I do not expect it would be too large but having some numbers for cache cold parallel kbuild or other heavy page lock workloads. -- Michal Hocko SUSE Labs
