> I can see such definitions are tagged as "obsolete" in the uapi headers. > Do we need some ifndef protection with the glibc headers? They should be still supported, but also the more generic macro. > > What is the advice to follow for userspace? Skip <linux/shm.h> and > openly redefine the SHM_HUGE_* wherever needed? glibc (or other C libraries if not using linux/shm) should add the defines. Short term you would need to redefine on your own yes. -Andi