On Fri, Feb 11, 2022 at 11:33:39AM -0500, Mouse wrote: > >> sparc64: [...] > > Almost forgot to mention ... I wouldn't read too much into how sparc64's > > bar$ > > Is that choice run-time configurable? I thought it was baked into the > hardware...but admittedly that's based on documents I read Quite Some > Time Ago.
For v9 it can be set per process even. See the TSTATE_MM_* bits: #define PSTATE_MM 0x0c0 /* memory model */ #define PSTATE_MM_TSO 0x000 /* total store order */ #define PSTATE_MM_PSO 0x040 /* partial store order */ #define PSTATE_MM_RMO 0x080 /* Relaxed memory order */ And we use TSO for the kernel: #define PSTATE_KERN (PSTATE_MM_TSO|PSTATE_PRIV) so Jason is correct. For userland we default to RMO for 64bit binaries (but honor their elf flags), and TSO for 32bit. Martin
