On Sun, Dec 08, 2019 at 06:23:02PM -0800, Linus Torvalds wrote: > On Sun, Dec 8, 2019 at 5:49 PM Arthur Marsh > <arthur.marsh@xxxxxxxxxxxxxxxx> wrote: > > > > This still happens with 5.5.0-rc1: > > Does it happen 100% of the time? > > Your bisection result looks pretty nonsensical - not that it's > impossible (anything is possible), but it really doesn't look very > likely. Which makes me think maybe it's slightly timing-sensitive or > something? > > Would you mind trying to re-do the bisection, and for each kernel try > the mount thing at least a few times before you decide a kernel is > good? > > Bisection is very powerful, but if _any_ of the kernels you marked > good weren't really good (they just happened to not trigger the > problem), bisection ends up giving completely the wrong answer. And > with that bisection commit, there's not even a hint of what could have > gone wrong. FWIW, the thing that is IME absolutely incompatible with bisection is CONFIG_GCC_PLUGIN_RANDSTRUCT. It can affect frequencies badly enough, even in the cases when the bug isn't directly dependent upon that thing. I suspect that nonsense bisects spewed by CI bots lately (bisect on x86 oops ending up at commit limited to arch/parisc, etc.) are at least partially due to that kind of garbage...
