On 6/7/07, Heiko Carstens <[EMAIL PROTECTED]> wrote:
> The smp_call_function{_single} functions are used to run > given function on all {or speicified} *other* CPUs. For > UP systems, "other" CPUs simply don't exist, so we flag > such incorrect usage of these functions using a WARNING.If other cpus don't exist then smp_call_function() should just do *nothing* (there is no other cpu right?). We don't want to sprinkle a ton of #ifdef CONFIG_SMP around each smp_call_function().
Yes, I suspected that, as mentioned on the other thread (ugh).
> Also, -EBUSY is generally returned by arch implementations > when they find that target_cpu == current_cpu, which is not > a comparable case to the !SMP case. Use -EINVAL instead, > similar to what powerpc does for !cpu_online(target), which > is somewhat more analogous. No. Current semantics of smp_call_function_single() are that it returns -EBUSY if called on the *current* cpu. Since on !CONFIG_SMP the only possible cpu it can be called on is the current one, the only sane return value is -EBUSY.
The inherent assumption that on !SMP the only possible CPU it can be called on is current (== 0) is precisely what I would want to be asserted formally in the code over here. If so, then return -EBUSY, else -EINVAL? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
