[weblacky]

Because this might affect me someday as well I'd like to know the answer. Looking around I only found one old post that talks about changes required to prevent something like this and lower memory being the immediate fix to it. But these are source code changes to the capture application (https://lost-contact.mit.edu/afs/pdc.kth...cord.dmic/). And I don't know whether the source is in all the distributions that you can simply hit rebuild or how this came about. So someone does need to do a little bit of extra work but this is what I found:

http://archive.irixnet.org/apocrypha/nek...rob/1.html

Post:

rooprob
Who joined Sept. 1, 2010, 6:20 a.m.
and authored 37 notes
Wrote on the subject of O2 dmrecord error at Feb. 16, 2012, 4:17 p.m...
May as well complete this thread.

I found the reason in the source for dmrecord.dmic (/usr/share/src/dmedia), which it seems to share behaviour of the stock utility /usr/sbin/dmrecord.

capture.c
DC(dmBufferSetPoolDefaults(p,options.outbufs,video.xferbytes,DM_TRUE,DM_TRUE));

The establishment of the buffer for the video -> compressor sets both cacheable and mapped to TRUE. This is actually a cache coherency overhead when passing data between the two pools which seems to drive the system into a problem state. When I set to FALSE, I observe consistent realtime compression without any issues over and over.

That was a bit of a rat hole. Learned about the dmedia libraries, written three different versions of dmrecord (forking and event driven), a par parser, some graphviz transformations of the call trace data. Pretty pictures too

Educational, but it was finding jrecvid.c on ftp.sgi.com (amazingly still functional) and on a hunch that led me to the apparent fix. Learning is fun.

I'm transitioning jobs at the moment which is why I have a stupid amount of free time right now to expend on this puzzle. (I'm not allowed to touch much at my current job, just hang around to answer questions until the end of the month). I may consider learning motif to make a little UI for my doings.