On 05.06.2011 17:26, Ingo Molnar wrote: > > * Ingo Molnar <mingo@xxxxxxx> wrote: > >> >> * Arne Jansen <lists@xxxxxxxxxxxxxx> wrote: >> >>> sched.c:934: in function __task_rq_lock >>> lockdep_assert_held(&p->pi_lock); >> >> Oh. Could you remove that line with the patch below - does it result >> in a working system? >> >> Now, this patch alone just removes a debugging check - but i'm not >> sure the debugging check is correct - we take the pi_lock in a raw >> way - which means it's not lockdep covered. >> >> So how can lockdep_assert_held() be called on it? > > Ok, i'm wrong there - it's lockdep covered. > > I also reviewed all the __task_rq_lock() call sites and each of them > has the pi_lock acquired. So unless both Peter and me are blind, the > other option would be some sort of memory corruption corrupting the > runqueue. Another small idea, can we install the assert into a pre-0122ec5b02f766c to see if it's an older problem that just got uncovered by the assert? -Arne > > But ... that looks so unlikely here, it's clearly heavy printk() and > console_sem twiddling that triggers the bug, not any other scheduler > activity. > > Thanks, > > Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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