On Tuesday 09 November 2010, Richard Cochran wrote: > On Mon, Nov 08, 2010 at 07:56:50AM +0100, Arnd Bergmann wrote: > > On Thursday 04 November 2010, Richard Cochran wrote: > > > #define CPUCLOCK_PERTHREAD_MASK 4 > > > #define CPUCLOCK_WHICH(clock) ((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK) > > > #define CPUCLOCK_CLOCK_MASK 3 > > > @@ -28,12 +40,17 @@ struct cpu_timer_list { > > > #define CPUCLOCK_VIRT 1 > > > #define CPUCLOCK_SCHED 2 > > > #define CPUCLOCK_MAX 3 > > > +#define CLOCKFD CPUCLOCK_MAX > > > +#define CLOCKFD_MASK (CPUCLOCK_PERTHREAD_MASK|CPUCLOCK_CLOCK_MASK) > > > > It looks like you are turning a kernel internal interface into a user ABI, > > which I think is highly questionable. Using the bits like this internally is > > ok, but making it part of the syscall ABI means that we can never change this > > in the future. > > This set of defines is already part of the ABI and has been copied > into glibc. I am extending the (mis)use of the clock id by adding one > more case. Ok, that is very different then. I wonder why posix-timers.h is not an exported header file, it might be good to change that to make it explicit which parts of it define the ABI and which parts are kernel internal. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html