On 8/30/06, Esben Nielsen [off-list ref] wrote:

On Tue, 29 Aug 2006, Li Yang wrote:

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This is exactly how it is supposed to work! That's why there is a loop
in the atomic increment - you check if you still had the reservation
after the transaction by checking the result from the stwcx, and if not,
retry.

I surely know all the theories you mentioned clearly.  But please do
look at the case I gave.  Correct me if I missed anything.  Thanks

All the lwarx and stwcx operate on the same address.

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Task A               Task B
lwarx

// Get RESERVATION

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                     ......
                     lwarx
                     stwcx

// RESERVATION cleared

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                     .....
                     .....
                     lwarx

// Get RESERVATION again

Now we do a task switch involving atomic operations, and thus an
reservation on another address.

This makes sense for me.