Re: length of iso packets
Brought to you by:
aeb,
bencollins
From: Manfred W. <e95...@st...> - 2000-04-25 21:19:39
|
Andreas Bombe wrote: > It made it better for me. I guess it does help, but just not enough > for you. It seems to be a symptom of interrupts not being served fast > enough. Do you probably have some drivers running that take a lot of > irq time (e.g. vesa fb)? Otherwise the data copying might really > overload your system. I do not use vesa fb. But maybe the reason could be the high data rate on that iso channel. I am receiving a complete MPEG 2 transport stream, which is iirc about 50 MBit/s. And the complete data is copied again in user space to the buffers of my software (which is not very efficient; I will improve that sometime in future), and a part of the data (which is intended to be decoded) is copied once again. Maybe there are too many copies (and the discussion about "DMA to userspace" tells me that copying the data could obviously cause performance problems). And since I also do some decoding, there is really high load on my system. This might be the reason. Manfred Weihs |