Messages in this thread | | | Date | Thu, 27 Dec 2012 18:41:38 +0000 | From | "Jan Beulich" <> | Subject | Re: [RFC PATCH 3/3 -v2] x86,smp: auto tune spinlock backoff delay factor |
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>>> 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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