Messages in this thread | | | From | KOSAKI Motohiro <> | Date | Thu, 2 Feb 2012 18:00:45 -0500 | Subject | Re: ksm/memory hotplug: lockdep warning for ksm_thread_mutex vs. (memory_chain).rwsem |
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2012/2/2 Gerald Schaefer <gerald.schaefer@de.ibm.com>: > Setting a memory block offline triggers the following lockdep warning. This > looks exactly like the issue reported by Kosaki Motohiro in > https://lkml.org/lkml/2010/10/25/110. Seems like the resulting commit a0b0f58cdd > did not fix the lockdep warning. I'm able to reproduce it with current 3.3.0-rc2 > as well as 2.6.37-rc4-00147-ga0b0f58. > > I'm not familiar with lockdep annotations, but I tried using down_read_nested() > for (memory_chain).rwsem, similar to the mutex_lock_nested() which was > introduced for ksm_thread_mutex, but that didn't help.
Heh, interesting. Simple question, do you have any user visible buggy behavior? or just false positive warn issue?
*_nested() is just hacky trick. so, any change may break their lie. Anyway I'd like to dig this one. thanks for reporting.
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