On 2014/7/8 4:05, Peter Zijlstra wrote: > On Mon, Jul 07, 2014 at 09:55:43AM -0400, Sasha Levin wrote: >> I've also had this one, which looks similar: >> >> [10375.005884] BUG: spinlock recursion on CPU#0, modprobe/10965 >> [10375.006573] lock: 0xffff8803a0fd7740, .magic: dead4ead, .owner: >> modprobe/10965, .owner_cpu: 15 >> [10375.007412] CPU: 0 PID: 10965 Comm: modprobe Tainted: G W >> 3.16.0-rc3-next-20140704-sasha-00023-g26c0906-dirty #765 > > Something's fucked; so we have: > > debug_spin_lock_before() > SPIN_BUG_ON(lock->owner == current, "recursion"); >
Hello, Does ACCESS_ONCE() can help this issue? I have no evidence that its lack is responsible for the issue, but I think here need it indeed. Is that right? SPIN_BUG_ON(ACCESS_ONCE(lock->owner) == current, "recursion"); Thanks, Li Bin > Causing that, _HOWEVER_ look at .owner_cpu and the reporting cpu!! How > can the lock owner, own the lock on cpu 15 and again contend with it on > CPU 0. That's impossible. > > About when-ish did you start seeing things like this? Lemme go stare > hard at recent changes. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/