On Fri, 29 Oct 2004 09:59:22 +0200, Duncan Sands <[EMAIL PROTECTED]> wrote:
> > > Most interesting. How many URBs do you use? > > > > It's configurable. I think I'm using 100 16KB URBs right now. That's > > probably overkill, but our hardware can only tolerate about 200 us > > worth of jitter before it over/under runs. > > Do you ever have problems finding 100 * (4 contiguous pages) of kernel > memory? It's virtually guaranteed to have problems with order 2 allocations. Two pages at a time can be found, but not four. Actually, statistically, they should be available, in the tail of the curve, so to speak. But the stock VM in 2.6 is not sufficiently persistent to keep trying. RHEL 3 has special code which repeats allocations of 4 pages indefinitely and guess what, I do get reports of hung processes of s390 where top page table directories are 4 pages in size. -- Pete ------------------------------------------------------- This SF.Net email is sponsored by: Sybase ASE Linux Express Edition - download now for FREE LinuxWorld Reader's Choice Award Winner for best database on Linux. http://ads.osdn.com/?ad_id=5588&alloc_id=12065&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
