Messages in this thread | | | Date | Fri, 26 Dec 2014 02:01:33 -0500 | From | Sasha Levin <> | Subject | Re: sched: spinlock recursion in sched_rr_get_interval |
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On 12/26/2014 01:45 AM, Li Bin wrote: > 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");
Could you explain a bit more why do you think it's needed?
Thanks, Sasha
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