On 04/02/2011, at 13:26, Daniel O'Connor wrote: > I only have about 10 milliseconds of buffering (96kbyte FIFO, 8Mbyte/sec) in > the hardware, however I have about 128Mb of USB requests queued up to libusb. > hps@ informed me that libusb will only queue 16kbyte (2msec) in the kernel at > one time although I have increased this.
We have upped the hardware FIFO size to 768kb, which is 91msec at 8Mb/sec, although due to the fact we only start reading out when it's 1/6th full the effective buffer is 75msec. It does seem much more resilient to CPU load, however heavy disk activity on the same drive still stalls it for too long :( Given the large buffering in the program it does seem very odd that it would stall for long enough unless both threads are slept while one is waiting for disk IO (which seems like a bug to me). BTW I have changed to -current (without WITNESS). -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
