Re: Sleeping in RCU list traversal

[Tetsuo Handa]

Hello.

Jun WANG wrote:
> I'm sorry,I think I got your idea, if you do not need ptr in
> my_task_that_may_sleep(), why you need to grab a reference to "ptr". If
> your my_task_that_may_sleep() needs ptr, and according to the 
> "memory region pointed by "ptr" never be removed." you say,
> it is ok to use "ptr" after rcu_read_ulock(). The basic idea behind RCU
> is to split updates into "removal" and "reclamation" phases. If you
> memory region pointed by "ptr" will not "reclamation" in sleep, it is ok
I need "ptr" in my_task_that_may_sleep(), but regarding my case,
memory region pointed by "ptr" will never be kfree()ed.

So, I don't need to grab a reference to "ptr"
because memory region pointed by "ptr" will never be kfree()ed.
And it is legal to use "ptr" after rcu_read_unlock()
because memory region pointed by "ptr" will never be kfree()ed.

Thank you.

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