On Fri, 10 Mar 2017 09:22:45 +0000, John Lenton wrote: > Hello! > > We're seeing a weird issue with either go, pthreads, or the kernel. If > you're knowledgeable about one or more of those things, could you take > a look? Thank you. > > The issue manifests as nasty warnings from the "snap run" command, > which is also the first step into a snapped app or service. It looks > like > > runtime/cgo: pthread_create failed: Resource temporarily unavailable > > a very stripped-down reproducer is http://pastebin.ubuntu.com/24150663/ > > build that, run it in a loop, and you'll see a bunch of those messages > (and some weirder ones, but let's take it one step at a time). > > if you comment out the 'import "C"' line the message will change but > still happen, which makes me think that at least in part this is a Go > issue (or that we're holding it wrong). > > Note that the exec does work; the warning seems to come from a > different thread than the one doing the Exec (the other clue that > points in this direction is that sometimes the message is truncated). > You can verify the fact that it does run by changing the /bin/true to > /bin/echo os.Args[1], but because this issue is obviously a race > somewhere, this change makes it less likely to happen (from ~10% down > to ~.5% of runs, in my machines). > > One thing that makes this harder to debug is that strace'ing the > process hangs (hard, kill -9 of strace to get out) before reproducing > the issue. This probably means we need to trace it at a lower level, > and I don't know enough about tracing a process group from inside the > kernel to be able to do that; what I can find about kernel-level > tracing is around syscalls or devices. > > Ideas?
Aside from being able to reproduce what you see I have done no analysis against this but may I sugges using bcc[1] instead of strace? There's a snap for it too ;-) [1] https://github.com/iovisor/bcc -- Sent using Dekko from my Ubuntu device -- Snapcraft mailing list Snapcraft@lists.snapcraft.io Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/snapcraft