On Wed 27-06-18 09:50:01, Vlastimil Babka wrote: > On 06/27/2018 09:34 AM, Michal Hocko wrote: > > On Tue 26-06-18 10:04:16, Andrew Morton wrote: > > > > And as I've argued before the code would be wrong regardless. We would > > leak the memory or worse touch somebody's else kmap without knowing > > that. So we have a choice between a mem leak, data corruption k or a > > silent fixup. I would prefer the last option. And blowing up on a BUG > > is not much better on something that is easily fixable. I am not really > > convinced that & ~__GFP_HIGHMEM is something to lose sleep over. > > Maybe put the fixup into a "#ifdef CONFIG_HIGHMEM" block and then modern > systems won't care? In that case it could even be if (WARN_ON_ONCE(...)) > so future cases with wrong expectations would become known.
Yes that could be done as well. Or maybe we can make __GFP_HIGHMEM 0 for !HIGHMEM systems. Does something really rely on it being non-zero? -- Michal Hocko SUSE Labs
