I am looking at performance issues on our DM355 based design. The DM355 passes through BT.656 video while overlaying graphics, and reads data from an external video compressor via the EMIF. It then writes that data to SDHC card or USB memory stick (and does some other things related to generating the graphics).
I am seeing an issue where the system will run ok for a while, then will start to drop data from the compressor. The compressor driver is running OK but it seems that my userland program that takes the data and writes it will suddenly stall causing the compressor driver to run out of buffer space. I suspect that this is something to do with flushing data out to the SD/USB device but don't know how to analyse the behaviour and work on a fix (assuming a fix is possible and I'm not running up against absolute hardware performance limits). I have been looking at OProfile and LTT. I'm not sure OProfile will do what I want, to analyse the moments where the userland process stalls. I am looking at LTT which looks good, but I have yet to see if I can get it working on the DM355. I am scratching in the dirt, so I thought I'd send this email; if anyone has any thoughts about how to analyse this problem, or what might be causing it, I'd like to hear them. Thanks, -- Jon Povey, Design Engineer [EMAIL PROTECTED] | +44(0)1280 825983 Racelogic is a limited company registered in England. Registered number 2743719 . Registered Office Unit 10, Swan Business Centre, Osier Way, Buckingham, Bucks, MK18 1TB . The information contained in this electronic mail transmission is intended by Racelogic Ltd for the use of the named individual or entity to which it is directed and may contain information that is confidential or privileged. If you have received this electronic mail transmission in error, please delete it from your system without copying or forwarding it, and notify the sender of the error by reply email so that the sender's address records can be corrected. The views expressed by the sender of this communication do not necessarily represent those of Racelogic Ltd. Please note that Racelogic reserves the right to monitor e-mail communications passing through its network _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
