On Tue, 2015-02-10 at 04:54 -0800, Eric Dumazet wrote: > Hi Michal > > This is almost it ;) > > As I said you must do this using u64 arithmetics, we still support 32bit > kernels. > > Also, >> 20 instead of / 1000000 introduces a 5% error, I would use a > plain divide, as the compiler will use a reciprocal divide (ie : a > multiply) > > We use >> 10 instead of /1000 because a 2.4 % error is probably okay. > > ewma_add(&ar->tx_delay_us, > ktime_to_ns(ktime_sub(ktime_get(), > skb_cb->stamp)) / > NSEC_PER_USEC); btw I suspect this wont compile on 32 bit kernel You need to use do_div() as well : u64 val = ktime_to_ns(ktime_sub(ktime_get(), skb_cb->stamp)); do_div(val, NSEC_PER_USEC); ewma_add(&ar->tx_delay_us, val); -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
