On 1-4-2016 11:34, Willem Jan Withagen wrote: > On 1-4-2016 07:12, Mykola Golub wrote: >> On Thu, Mar 31, 2016 at 07:10:45PM +0200, Willem Jan Withagen wrote: >> >>> Does anybody have suggestions as how to track/debug this? >> >> valgrind? >> > > Yup, tried that one, but it is sort of hard to find an intermittent > erroneous write. I tried --track-addr=<addr of m_exp_len> But most of > the time it is only written at exact the code line it is supposed to be > written. So no info there. > > So perhaps I need a different set of tests? > > On average I need about 600 runs to catch one SIGSEGV. > > BTW: tried it on 2 FreeBSD systems, and on both the behaviour is > identical. So it has got to be the code. And since 65000 runs on Linux > give no errors, it is also typical for the combo > FreeBSD/Clang/FreeBSD-packages. And it gets even weirder. Clang allows to use of AddressSanitizer ( https://github.com/google/sanitizers/wiki/AddressSanitizer ) So i've compiled all of ceph with -fsanitize=address -fno-omit-frame-pointer And now I've already logged 50.000 runs without crashes. Feels a lot like Schrödinger's cat.... --WjW -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html