On 11/17/2010 10:52 AM, Jeremy Fitzhardinge wrote: > On 11/17/2010 12:31 AM, Jan Beulich wrote: > >>>> On 16.11.10 at 22:08, Jeremy Fitzhardinge<[email protected]> wrote: > >> +static inline void __ticket_enter_slowpath(struct arch_spinlock *lock) > >> +{ > >> + if (sizeof(lock->tickets.tail) == sizeof(u8)) > >> + asm (LOCK_PREFIX "orb %1, %0" > >> + : "+m" (lock->tickets.tail) > >> + : "i" (TICKET_SLOWPATH_FLAG) : "memory"); > >> + else > >> + asm (LOCK_PREFIX "orw %1, %0" > >> + : "+m" (lock->tickets.tail) > >> + : "i" (TICKET_SLOWPATH_FLAG) : "memory"); > >> +} > > Came only now to mind: Here and elsewhere, did you try using > > %z0 to have gcc produce the opcode suffix character, rather > > than having these somewhat ugly if()-s? > > Actually in this case I'm pretty sure there's already a "set bit" > function which will do the job. set_bit(), I guess, though it takes a > bit number rather than a mask... >
set_bit() operates on a long, while the intel manuals recommend against operating on operands of different size, especially with locked operations. I think newer processors have more relaxed requirements, though. -- error compiling committee.c: too many arguments to function _______________________________________________ Virtualization mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/virtualization
