[vdr] Thread priority of cutting thread in vdr

Klaus Schmidinger Klaus.Schmidinger at cadsoft.de
Mon Oct 10 10:16:29 CEST 2005


Emil Naepflein wrote:
> On Mon, 10 Oct 2005 09:54:56 +0300, Marko Mäkelä wrote:
> 
> 
>>On Mon, Oct 10, 2005 at 06:52:12AM +0200, Emil Naepflein wrote:
>>
>>>This is pretty useless on my system because the loss of responsiveness
>>>is mostly caused by the disk accesses and not by cpu usage. 
>>
>>Are you sure that DMA disk transfers are enabled? If not, the copying
>>with programmed I/O (PIO) will consume CPU.
> 
> 
> As I wrote, there is no problem with cpu usage. And DMA is enabled as I
> use a Promise SX6000 controller (SCSI interface). The main problem is
> that the cutting thread reads and writes the data through the buffer
> cache and purges useful data from the buffer cache. Any disk access when
> using the menu then is delayed considerably. This is with a 2.4 kernel.
> The 2.6 kernel behaves much better in this regard.
> 
> Emil

I'm currently in the process of adopting Ralf Müller's patch
to avoid trashing the disk cache. Maybe that will help.

Klaus



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