Messages in this thread | | | Date | Tue, 25 Feb 2014 10:06:36 -0500 | From | Tejun Heo <> | Subject | Re: [cgroup/task_lock] INFO: suspicious RCU usage. |
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Hello, Li.
On Tue, Feb 25, 2014 at 08:01:25PM +0800, Li Zefan wrote: ... > >> So, this is from removing task_lock from task_css_set_check() and > >> adding rcu_read_lock() in cpuset_cpus_allowed() should fix it. > > > > Yeah, rcu_read_lock() should be sufficient. > > > >> I'm > >> not sure how much of task_lock() locking we currently have in cpuset > >> is actually necessary tho. Shouldn't we be able to do most with just > >> callback_mutex, if not cpuset_mutex? Li, any ideas? > >> > > > > task_lock() is also used to protect task->mems_allowed. I'll see if we > > can get rid of most (if not all) task_lock() lockings in cpuset. > > > > After a quick lock, I think except the one in cpuset_change_task_nodemask(), all > other task_lock() lockings can be replace by rcu_readlock().
I committed the original series as-is. Can you please post follow-up patches to update cpuset locking?
Thanks.
-- tejun
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