Hi Remi, On Wednesday 17 December 2008 21:27:49 Remi Lefevre wrote: > >> Also 40% seems quite a lot, even at 1000Hz interruptions, an idea how > >> much does the CRC computation contribute in this CPU hogging ? > > > > I haven't measured that, but probably not much. The biggest CPU time > > eater isn't the SOF generation interrupt but the USB packet handling > > code. The CPM2 USB host controller is really too low-level to be usable > > (except maybe for specific applications). Comparing the OHCI/UHCI/EHCI > > and FHCI controllers is akin to bit like comparing a full 16550 UART > > with a software bit-bang implementation. You can get around with it, it > > might work for your specific application, but you shouldn't try a full > > speed 115200bds communication while computing a CPU-hungry physical > > simulation. > > That's what I was afraid of. I now understand clearly why you didn't expect > that much better performance with CPM3 in a past message > (http://ozlabs.org/pipermail/linuxppc-embedded/2008-May/030508.html). > Still, as you said, it can have some use for specific applications. > > Do you remember the throughput you were able to reach with this cpu > overhead ?
I'm sorry I don't. Best regards, -- Laurent Pinchart CSE Semaphore Belgium Chaussee de Bruxelles, 732A B-1410 Waterloo Belgium T +32 (2) 387 42 59 F +32 (2) 387 42 75 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
