Also we've gotten around this limit by treating that 8mb as a ring buffer and having a C program which streams data from that ring buffer into a much larger userland malloc()ed buffer.
On Thursday, November 7, 2013 10:22:45 AM UTC-5, cmicali wrote: > > 0x800000 is the max amount I've been able to allocate. I think it has > something to do with max size allowed by dma_alloc_coherent with the > GFP_KERNEL flag. The max with the beaglebone white (256mb ram instead of > 512mb) was 0x400000. So far I haven't been able to turn up where these > limits may be coming from though.. someone suggested it may be tunable with > a kernel parameter. > > > > On Thursday, November 7, 2013 12:32:11 AM UTC-5, [email protected] wrote: >> >> I'm running Angstrom (Linux 3.8.13, September 12, 2013) on a BeagleBone >> Black and I've tried configuring uio_pruss to allocate a large amount of >> external memory, but I have found that sizes greater than 8MB don't work >> and lead to uio_pruss failure. >> >> The command I have been trying is: >> >> /sbin/modprobe uio_pruss extram_pool_sz=0x800001 >> >> >> ... and the error message I receive is: >> >> pruss_uio 4a300000.pruss: Could not allocate external memory >> >> >> I would like to allocate more than 8MB of external memory for PRU access. >> Is it possible to allocate more than 8MB? If so, what can I do to make it >> work? >> > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
