[Tile-serving] mod_tile causes segfault on debian 7.0
tom at compton.nu
Wed May 22 11:49:41 UTC 2013
On 22/05/13 12:34, Andy Allan wrote:
> On 22 May 2013 12:06, Sven Geggus <lists at fuchsschwanzdomain.de> wrote:
>> I get segmentation faults in mod_tile on a more or less regular basis which
>> will leave apache in a 100% CPU on all cores state!
> Ah, that's interesting, I'm seeing something very similar. I'm using
> 1341e129e5 (22 April) with apache2-mpm-event 2.2.22 (on Ubuntu 12.04)
> I'm not sure that commit is necessarily involved, since it doesn't
> change anything for apache 2.2, but perhaps the bug was introduced
> elsewhere and that commit is just a symptom? I'm just using renderd
> with a normal disk backend, if that helps.
The point is that before the pluggable storage backends were added that
code didn't exist at all.
Once they were added the use of the process pool in a function that
might be called in multiple threads at once was not robust, so that
commit was added to make things robust.
Unfortunately there is no way (that Kai has found) to get a per-thread
memory pool on 2.2 so the old code is still used there, which will quite
likely crash if you are using a threaded mpm.
Tom Hughes (tom at compton.nu)
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