On Wed 23-05-18 19:15:51, Anshuman Khandual wrote: > On 05/23/2018 06:25 PM, Michal Hocko wrote: > > when adding memory to a node that is currently offline. > > > > The VM_WARN_ON is just too loud without a good reason. In this > > particular case we are doing > > alloc_pages_node(node, GFP_KERNEL|__GFP_RETRY_MAYFAIL|__GFP_NOWARN, order) > > > > so we do not insist on allocating from the given node (it is more a > > hint) so we can fall back to any other populated node and moreover we > > explicitly ask to not warn for the allocation failure. > > > > Soften the warning only to cases when somebody asks for the given node > > explicitly by __GFP_THISNODE. > > node hint passed here eventually goes into __alloc_pages_nodemask() > function which then picks up the applicable zonelist irrespective of > the GFP flag __GFP_THISNODE. __GFP_THISNODE should enforce the given node without any fallbacks unless something has changed recently. > Though we can go into zones of other > nodes if the present node (whose zonelist got picked up) does not > have any memory in it's zones. So warning here might not be without > any reason. I am not sure I follow. Are you suggesting a different VM_WARN_ON? -- Michal Hocko SUSE Labs
