Messages in this thread | | | Date | Tue, 3 Nov 2015 01:55:39 -0800 | From | "Paul E. McKenney" <> | Subject | Re: Can srcu_read_lock() be called from interrupt context? |
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On Mon, Nov 02, 2015 at 05:56:56PM -0800, Yunhong Jiang wrote: > Hi, Paul > I have a question to the srcu_read_lock(). Can it be invoked on > interrupt context? According to > http://lxr.free-electrons.com/source/kernel/rcu/srcu.c#L292 it can only be > called from process context, but according to > http://lxr.free-electrons.com/source/include/linux/srcu.h#L213 seems it's ok > from irq context only if it matches with the srcu_read_unlock. Can you > please give some hints?
Adding Lai Jianshan for his thoughts.
I believe that srcu.h is correct, at least assuming that interrupts do not nest too deeply. (If they were to nest four billion deep, then the ->seq[] counter could overflow, defeating the checks, but the CPU stack would have overflowed long before.)
Lai, am I missing anything here?
Thanx, Paul
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