[Click] High CPU usage with BandwidthShaper Element

[Aziz Adel]

Hello,

I am a new user to Click and I noticed that the BandwidthShaper Element is using all my CPU power (266 Mhz on Asus router) when I limit the rate below the capacity of the wireless channel (i.e. the queue of the MAC layer is most of the time empty).
I noticed that this problem, does not occur, when I set a higher rate that is able to fill the MAC queue (which basically means that the BandwidthShaper is not limiting anything). Thus, I am guessing that the problem might come from the "pull" method (see below) that is always called by the MAC layer and that heavily uses the CPU due to the Timestamp::now() calls.
------------------------
Packet *
BandwidthShaper::pull(int)
{
    Packet *p = 0;
    if (_rate.need_update(Timestamp::now())) {
    if ((p = input(0).pull()))
        _rate.update_with(p->length());
    }
    return p;
}
-------------------

I wanted to know if any other user also encountered this problem and how did he solved it?
In a C code, my guess would have been to add and "else" part and put use the "usleep()" function in order to limit too many pull calls by delaying the answer, but this does not seem to compile as is and I did not find an equivalent to "usleep()" that could be used with the Click code.

If anyone has any hint for how to go over my problem, it would be really nice :)

Best,

Adel