On Sunday 24 August 2008 00:52:49 Benjamin Herrenschmidt wrote: > On Sat, 2008-08-23 at 16:10 +0200, Michael Buesch wrote: > > I am seeing random kernel and userland application > > crashes on a Powerbook running a 2.6.27-rc3 based kernel > > (wireless-testing.git). > > > > The crashes did recently appear. It might be the case that they were > > introduced with the merge of 2.6.27-rc1 into wireless-testing. > > I'm not sure on that one, however. Just a guess. I still need to > > do more testing (also on vanilla upstream kernels). > > > > The crashes are completely random and they look like bad hardware. > > However I cannot reproduce on 2.6.25.9 (That's a kernel I still had > > installed, so I tried that one). So it most likely is _not_ caused > > by faulty hardware. > > > > The crashes are hard to reproduce, and happen about every 20 minutes > > when compiling a kernel tree. (gcc segfaults). Sometimes the kernel > > oopses in random places with pointer dereference faults. > > > > Is this a known issue? > > I'm going to bisect this one, but it will take a lot of time, as reproducing > > takes about 20 minutes. So that's about an hour for one test round. > > > > The kernel configuration is the following: > > Random guess: > > CONFIG_FRAME_POINTER=y > CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER=y > > Note sure what those together do, check if you have any file compiled > with -fno-omit-frame-pointer and if you do, try to change things so > that you don't ... we found some miscompiles when that is set, exposed > by FTRACE typically (which you don't have enabled) but possibly by other > things.
Ok, thanks for the suggestion. I could reproduce the crash with 2.6.26, so this is not a regression between 2.6.26 and 2.6.27-rcX. I'm currently running longer tests on 2.6.25 again to make sure it really isn't hardware related. NO_NO_OMIT is a brain screwer, btw :) -- Greetings Michael. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
