Messages in this thread | | | Date | Thu, 27 Dec 2012 14:09:21 -0500 | From | Rik van Riel <> | Subject | Re: [RFC PATCH 3/3 -v2] x86,smp: auto tune spinlock backoff delay factor |
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On 12/27/2012 01:41 PM, Jan Beulich wrote: >>>> 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?
How much bus traffic do monitor/mwait cause behind the scenes?
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