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Date: Fri, 23 Feb 2007 13:08:14 -0800
From: "Kip Macy" <kip.macy@gmail.com>
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Subject: LOCK_PROFILING patch
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Tracking acquisition wait time on x86 is very expensive. The following
patch only looks at the time if the lock is contested so that we only
pay the price for timekeeping if we are going to actually have to wait
to acquire the lock.

http://www.fsmware.com/freebsd/lock_prof.diff