On Wed, 2018-10-24 at 14:36 +0200, Michal Hocko wrote: > On Wed 17-10-18 08:26:20, Alexander Duyck wrote: > [...] > > With that said I am also wondering if a possible solution to the > > complaints > > you had would be to look at just exporting the __init_pageblock > > function > > later and moving the call to memmap_init_zone_device out to the > > memremap or > > hotplug code when Dan gets the refactoring for HMM and memremap all > > sorted > > out. > > Why cannot we simply provide a constructor for each page by the > caller if there are special requirements? we currently have alt_map > to do struct page allocation but nothing really prevents to make it > more generic and control both allocation and initialization whatever > suits a specific usecase. I really do not want make special cases > here and there. The advantage to the current __init_pageblock function is that we end up constructing everything we are going to write outside of the main loop and then are focused only on init. If we end up having to call a per page constructor that is going to slow things down. For example just that reserved bit setting was adding something like 4 seconds to the init time for the system. By allowing it to be configured as a part of the flags outside of the loop I was able to avoid taking that performance hit. - Alex
