Re: [PATCH] Fix deadlock in RPC scheduling code.

Trond Myklebust wrote:

Yes. The RPC_TASK_QUEUED bit can only be cleared when both the
RPC_TASK_WAKEUP bit _and_ the queue spinlock are held.
If you are holding either one of those two, then it is safe to test for
RPC_IS_QUEUED(). If the latter is true, then it is also safe to
dereference the value of task->u.tk_wait.rpc_waitq.

Hmmm... With those constraints, it seems difficult to be able to modify the current rpc_wake_up_task() function...

But, are you sure the patch you provided is sufficient to remove the potential deadlock we faced ? I do not see how, could you explain ?

--
Aurelien Degremont

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