David Olofson wrote: > On Thursday 25 March 2010, at 12.49.31, Ralf Mardorf <ralf.mard...@alice- > dsl.net> wrote: > [...] > >> Btw. the >> graphics has access to the main memory, unfortunately it's a shared RAM, >> OTOH I used HPET so unwanted interrupts because of a shared RAM >> shouldn't be the cause, if I do understand the workings of HR timers >> correctly. >> > > Interrupts can't save you if bus-master DMA is blocking the CPU's access to > RAM. Whatever IRQ source and kernel interrupt handling code you're using has > no bearing on this. If the interrupts are generated by external or internal > (to the CPU) timers shouldn't matter either. (Even if external IRQs are > delayed while the bus is busy, it doesn't make a difference, as the CPU can't > respond until the bus is free anyway.) > > Either way, I don't think that should be a problem, as busmaster DMA is > normally done in short bursts, rather than large blocks. Unless you're > pushing > the limits of RT-Linux or RTAI, it should affect nothing but bandwidth from a > practical POV. Then again, perhaps not all hardware is that well behaved...? >
Thank you for the information. At least when doing test I guess the limits are untouched. Ralf _______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/listinfo/linux-audio-dev
