On 4/2/26 02:44, Andrew Morton wrote: > On Wed, 1 Apr 2026 17:34:16 -0700 Anthony Yznaga <[email protected]> > wrote: > >> On configs where MAP_DROPPABLE is not supported (currently any 32-bit >> config except for PPC32), mmap fails with errno set to ENOTSUPP. >> However, ENOTSUPP is not a standard error value that userspace knows >> about. The acceptable userspace-visible errno to use is EOPNOTSUPP. >> checkpatch.pl has a warning to this affect. > > Sounds very reasonable. > > EOPNOTSUPP is clearly a networking thing so what on earth is it doing > coming out of mmap code? Our poor operator is now looking at a networking > error code and wondering what this supposedly non-networking > application is up to. > > But just that's a pet peeve - I lost that one decades ago. > >> Fixes: 9651fcedf7b9 ("mm: add MAP_DROPPABLE for designating always lazily >> freeable mappings") > > Nearly two years ago so I think I'll add this to mm-unstable for > 7.1-rc1 and shall let it trickle back a little more slowly than might a > 7.0-rcX hotfix. > >
Acked-by: David Hildenbrand (Arm) <[email protected]> But ~/git/linux/mm$ git grep ENOTSUPP hugetlb_vmemmap.c: ret = -ENOTSUPP; mmap.c: return -ENOTSUPP; Should we fix up the other one as well? -- Cheers, David
