CPU Cache and busdma usage in USB
kosmo at semihalf.com
Wed Jul 8 10:16:43 UTC 2009
Wednesday 08 July 2009 11:03:43 Hans Petter Selasky napisał(a):
> And what about my patch suggestion in my previous e-mail having the same
> subject. Does it work?
I have tested it and it does not work. By the way Writeback before Writeback
Invalidate did not change cache behaviour too much. Writeback invalidate
means flush all modified cache lines and then invalidate cache.
However looking into logs which I have sent you yesterdat I see one difference
which may be significant. My patch changes Invalidate into Writeback
Invalidate. In original code if driver write something to memory and then
invalidate cache, the write will be lost. With my patch after change will
be written to memory and then cache will be invalidated. What do you think ?
More information about the freebsd-usb