On Mon, May 02, 2011 at 02:02:34PM -0700, Abu Rasheda wrote: > On Mon, May 2, 2011 at 12:28 PM, Greg KH <greg@xxxxxxxxx> wrote: > > On Mon, May 02, 2011 at 11:32:32AM -0700, Abu Rasheda wrote: > >> I am testing my driver on much faster host processor and facing > >> following issues: > >> > >> My host is too powerful and it can fill up device buffer queue very fast. > > > > What kind of device is this? > > its a networking device It sounds like a broken device, you need to be able to handle large data streams, right? Are you running Linux in this device and that is the issue you are having? > >> I get best performance when I do busy wait, but this is not desirable > >> and is bad design. > >> > >> I need to sleep and wake up quickly and predictability. Indication > >> from device that queue has space, is coming in form of memory write > >> (device writes to a memory location of i86 processor). > >> > >> I tried using wait_event_interruptible_timeout, I am depending on 2nd > >> parameter of the function but it wake up is too slow, even tried using > >> value of 1. > > > > Why not try increasing the buffer in your driver to handle any amount of > > data needed? > > Problem come from the fact that remote end can be slow, so device / > driver cannot do much. If I increase buffer size, than running on > (even) faster host processor will bring back same issue. I am looking > for solution which will scale. > > I check for available buffer size if space is low, I sleep and retry. > This is causing lot of CPU to be wasted. > > How can I optimize this ? Use NAPI for your network driver? good luck, greg k-h _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
