On Mon 08-03-21 15:13:35, David Hildenbrand wrote: > On 08.03.21 15:11, Michal Hocko wrote: > > On Mon 08-03-21 14:22:12, David Hildenbrand wrote: > > > On 08.03.21 13:49, Michal Hocko wrote: > > [...] > > > > Earlier in the discussion I have suggested dynamic debugging facility. > > > > Documentation/admin-guide/dynamic-debug-howto.rst. Have you tried to > > > > look into that direction? > > > > > > Did you see the previous mail this is based on: > > > > > > https://lkml.kernel.org/r/yeeuq8zrn4wyy...@google.com > > > > > > I agree that "nofail" is misleading. Rather something like > > > "dump_on_failure", just a better name :) > > > > Yeah, I have read through the email thread. I just do not get why we > > cannot make it pr_debug() and add -DDYNAMIC_DEBUG_MODULE for > > page_alloc.c (I haven't checked whether that is possible for built in > > compile units, maybe it is not but from a quick seems it should). > > > > I really do not like this to be a part of the API. alloc_contig_range is > > Which API?
Any level of the alloc_contig_range api because I strongly suspect that once there is something on the lower levels there will be a push to have it in the directly consumed api as well. Besides that I think this is just a wrong way to approach the problem. > It does not affect alloc_contig_range() itself, it's used > internally only. Sure, we could simply pr_debug() for each and every > migration failure. As long as it's default-disabled, sure. > > I do agree that we should look into properly including this into the dynamic > debugging ifrastructure. Yeah, unless we learn this is not feasible for some reason, which I do not see right now, then let's just make it pr_debug with the runtime control. -- Michal Hocko SUSE Labs
