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SubjectRe: [RFC PATCH 3/3 -v2] x86,smp: auto tune spinlock backoff delay factor
>>> Rik van Riel <riel@redhat.com> 12/27/12 4:01 PM >>>
>On 12/27/2012 09:27 AM, Eric Dumazet wrote:
>> So the hash sounds good to me, because the hash key could mix both lock
>> address and caller IP ( __builtin_return_address(1) in
>> ticket_spin_lock_wait())
>
>The lock acquisition time depends on the holder of the lock,
>and what the CPUs ahead of us in line will do with the lock,
>not on the caller IP of the spinner.

The lock holder could supply its __builtin_return_address(0) for use
in eventual hashing.

Also, with all of this - did you evaluate the alternative of using
monitor/mwait instead?

Jan



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