On Mon, Nov 06, 2023 at 02:06:22PM +0100, Nina Schoetterl-Glausch wrote: > > > +unsigned int stfle_size(void) > > > +{ > > > + static unsigned int size = 0; > > > + u64 dummy; > > > + > > > + if (!size) { > > > + size = __stfle_asm(&dummy, 1) + 1; > > > + } Please get rid of the braces here. checkpatch.pl with "--strict" should complain too, I guess. > > Possible races? Should have to use an atomic? > > Good point. Calling __stfle_asm multiple times is fine > and AFAIK torn reads/writes aren't possible. I don't see a way > for the compiler to break things either. > But it might indeed be nicer to use an atomic, without > any downsides. Please use WRITE_ONCE() and READ_ONCE(); that's more than sufficient here.