Messages in this thread | | | Date | Mon, 7 Jun 2010 17:19:29 -0700 | From | "Paul E. McKenney" <> | Subject | Re: 2.6.35-rc2-git1 - include/linux/cgroup.h:534 invoked rcu_dereference_check() without protection! |
| |
On Mon, Jun 07, 2010 at 02:14:25PM -0400, Miles Lane wrote: > Hi All, > > I just reproduced a warning I reported quite a while ago. Is a patch > for this in the pipeline?
I proposed a patch, thinking that it was a false positive. Peter Zijlstra pointed out that there was a real race, and proposed an alternative patch, which may be found at http://lkml.org/lkml/2010/4/22/603.
Could you please test Peter's patch and let us know if it cures the problem?
Thanx, Paul
> [ 0.167267] [ INFO: suspicious rcu_dereference_check() usage. ] > [ 0.167396] --------------------------------------------------- > [ 0.167526] include/linux/cgroup.h:534 invoked > rcu_dereference_check() without protection! > [ 0.167728] > [ 0.167729] other info that might help us debug this: > [ 0.167731] > [ 0.168092] > [ 0.168093] rcu_scheduler_active = 1, debug_locks = 1 > [ 0.168337] no locks held by watchdog/0/5. > [ 0.168462] > [ 0.168463] stack backtrace: > [ 0.168704] Pid: 5, comm: watchdog/0 Not tainted 2.6.35-rc2-git1 #8 > [ 0.168834] Call Trace: > [ 0.168965] [<ffffffff81064e9c>] lockdep_rcu_dereference+0x9d/0xa5 > [ 0.169100] [<ffffffff8102c1ce>] task_subsys_state+0x59/0x70 > [ 0.169232] [<ffffffff8103189b>] __sched_setscheduler+0x19d/0x2f8 > [ 0.169365] [<ffffffff8102a5ef>] ? need_resched+0x1e/0x28 > [ 0.169497] [<ffffffff813c7d01>] ? schedule+0x586/0x619 > [ 0.169628] [<ffffffff81081c33>] ? watchdog+0x0/0x8c > [ 0.169758] [<ffffffff81031a11>] sched_setscheduler+0xe/0x10 > [ 0.169889] [<ffffffff81081c5d>] watchdog+0x2a/0x8c > [ 0.170010] [<ffffffff81081c33>] ? watchdog+0x0/0x8c > [ 0.170141] [<ffffffff81054a82>] kthread+0x89/0x91 > [ 0.170274] [<ffffffff81003054>] kernel_thread_helper+0x4/0x10 > [ 0.170405] [<ffffffff813ca480>] ? restore_args+0x0/0x30 > [ 0.170536] [<ffffffff810549f9>] ? kthread+0x0/0x91 > [ 0.170667] [<ffffffff81003050>] ? kernel_thread_helper+0x0/0x10 > [ 0.176751] lockdep: fixing up alternatives. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |