sb-concurrency tests hang/fail on 12-core linux box

[Cyrus Harmon]

When attempting to build SBCL on this nice 12-core box here, things go very wrong on the sb-concurrency tests.

On teh first test, frlock.1, the load spikes to ~30 and the test eventually fails after timing out at 60 seconds. queue.1-4 tests pass, and maybe queue.4, but then things quickly go south again in queue.t.1, which passes but takes a really like time to do so.

I am trying this on linux 4.0.4, at the moment, but it has happened with other kernels as well, although at some point SBCL did build on this box, as I'm using 1.2.11.20, which i must have built. So, it's possible this is kernel related, but I've tried on some older kernels, but the box has been upgraded to a newer release of ubuntu, so it's hard to do an apples-to-apples test. In any event, something seems very wrong.

[Cyrus Harmon (ch-launchpad)]

Also, I should point out that this happens on both x86 and x86-64.

[Cyrus Harmon (ch-launchpad)]

Well, the bug seems to have gone away under 4.1.0-rc5. So, either it's a heisenbug or, more likely, there was some kernel problem that has been fixed. I'll try again on 4.0.4 one of these days to see if I can repeat it, but, at least for now, I'm closing this as invalid.