The Persistence of Vision Raytracer (POV-Ray).
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Opened by Jim Holsenback - 2012-09-28
Last edited by Jim Holsenback - 2012-09-30
FS#253 - Segmentation fault
I’ve had a series of what appear to be a hang up’s. They passed parse, reported some stats and issued the Rendering... message and opened the preview window, but never progressed. They continued to accumulate cpu time until I eventually had to kill -9, softer didn’t work.
I’ve been dismissing them up until now wanted to speak up because I finally got this crash:
29623 Segmentation fault
Here’s some observed behaviors:
In my scene I have a Round_Box_Union with /just/ a pigment that rendered fine, but when I added a wood texture from the distribution includes, it hung up after I tried to transform the texture in any way. Tried other distribution textures ... same thing.
I spent time going through different scenarios looking for a common cause (thinking I’m doing something wrong). Eventually I arrived at the point that I killed a hung render, and restarted the same render with no changes. Sometimes it would render, sometimes not ... I finally got the above mentioned Round_Box_Union to behave with a simple reflective texture, and the rounding parameter had to be above 0.1 ... I settled at 0.125. OK by now you’re thinking WTF right?
No more problems until I accidentally (typo) put an additional light_source at the same location as another light_source. It also hung sometimes, and rendered fine sometimes after a kill ... no SDL changes.
Now I can’t tell you exactly what I was doing when the seg fault happened, but I /do/ know I just restarted the render with no changes. I’m starting to think there’s some kind of instability happening here. I realize that I’m probably the only team member spending any real time with the application, so none of you probably haven’t noticed anything suspicious.
Any comments ... ideas ... suggestions?
Sunday, 30 September 2012, 13:33 GMT
Reason for closing: Not a bug
Additional comments about closing:
hardware issues
Please feed me!
Do you have a scene to provide here that would renders fast ? (and that would segfault)
(If it renders fast, using valgrind to check the memory access might be an option: the slowdown is about a factor 50 to 200, IIRC, and a debug/not stripped version of povray is better: –enable-debug on ./configure)
What were the setting for the render ? (size, did that size fit the screen or is scaled, animation ?)
It's linux, is it 64 or 32 bits ? (did you use #5717 or the true RC6 ?)
Did you run something like memtest86+ lately ? (paranoia: some part of your memory is bogus... unlikely but better check)
What is your system ? (CPU, speed, total ram, which distribution; do you overclock ?)
When does it hung ? (from the text stream: at parse, radiosity/photon or render stage)
ad hominem: We love you too.
Just as a quick intervention: No ad hominem to be seen from my point of view, only the neutral observation (which might be mistaken, but that's another story) that Jim seems to be the only one of us currently developing POV-Ray scenes for the sake of the scenes rather than testing purposes. Whether that is true or not, I find no fault in that behavior of ours, so how could it even be an accusation.
Jim,
If you can manage to make the crash happen with the windows version and then allow it to upload the crashdump, I could get a good idea of where it's happening.
Yesterday early I put in place all the observed behaviors that /appeared/ to be causing failures with no luck ... that is no failures until later on in the afternoon. I think I dealing with thermal hardware problem ... my box temperature was up a bit and one the the fails came back. At this point blame it on hardware.
And ... NO I was NOT asserting that I was the only one doing testing ... just scene active scene development as pointed out
Sorry if I stepped on any toes as that was not my intent.