On Sat, Sep 04, 2004, Holger Waechtler wrote:
As you can see the s/t/c-zap family of programs sets a buffer size of
64kByte on the demux device. This is not very much. Even a workstation can
be (disk-io) busy for a few seconds - not to mention a server. I do not
want to discuss the problem of missing (disk-)io priorities in the kernel,
but my question simply is:
IS IT RECOMMENDED AND SAFE TO USE A LARGER BUFFER?
I would feel better to tell the driver to grab 512 kByte of precious
kernel memory. What do you think?
you can do so if you want, that's the intention of this ioctl(). But is
it really needed? Our experiences showed that these values are usually
ok for normal environments.
What can be the cause of the EOVERFLOW error then ? I'm experiencing it
at least once a day on my machines, too. Is it in any way related to
a buffer size ?
Ralph is right, fixing this ioctl for the dvr device is an long
outstanding TODO -- currently it only resizes the buffers for the demux
device, I forgot this. Right now the buffer size is hardcoded in
linux/drivers/media/dvb/dvb-core/dmxdev.h: