On Mon 20-01-20 15:13:54, David Hildenbrand wrote: > On 20.01.20 15:11, Qian Cai wrote: > >> On Jan 20, 2020, at 9:01 AM, David Hildenbrand <david@xxxxxxxxxx> wrote: > >> On 20.01.20 14:56, Qian Cai wrote: [...] > >>>> FWIW, I'd prefer this change without any such cleanups (e.g., I don't > >>>> like returning a bool from this function and the IS_ERR handling, makes > >>>> the function harder to read than before) > >>> > >>> What is Michal or Andrew’s opinion? BTW, a bonus point to return a bool > >>> is that it helps the code robustness in general, as UBSAN will be able to > >>> catch any abuse. > >>> > >> > >> A return type of bool on a function that does not test a property > >> ("has_...", "is"...") is IMHO confusing. > > > > That is fine. It could be renamed to set_migratetype_is_isolate() or > > is_set_migratetype_isolate() which seems pretty minor because we > > have no consistency in the naming of this in linux kernel at all, i.e., > > many existing bool function names without those test of properties. > > It does not query a property, so "is_set_migratetype_isolate()" is plain > wrong. > > Anyhow, Michal does not seem to care. Well, TBH I have missed this change. My bad. I have mostly checked that the WARN_ONCE is not gated by the check and didn't expect more changes. But I have likely missed that change in the previous version already. You guys are too quick with new version to my standard. Anyway, I do agree that bool is clumsy here. Returning false on success is just head scratching. Nobody really consumes the errno value but I would just leave it that way or if there is a strong need to change then do it in a separate patch. -- Michal Hocko SUSE Labs