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 Re: [Xen-devel] [PATCH 05/11] qspinlock: Optimize for smaller	NR_CPUS
 
To: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>, Waiman.Long@xxxxxx,	tglx@xxxxxxxxxxxxx, mingo@xxxxxxxxxxFrom: Paolo Bonzini <pbonzini@xxxxxxxxxx>Date: Wed, 18 Jun 2014 13:39:52 +0200Cc: linux-arch@xxxxxxxxxxxxxxx, gleb@xxxxxxxxxx, kvm@xxxxxxxxxxxxxxx,	Peter Zijlstra <peterz@xxxxxxxxxxxxx>, scott.norton@xxxxxx,	raghavendra.kt@xxxxxxxxxxxxxxxxxx, paolo.bonzini@xxxxxxxxx,	linux-kernel@xxxxxxxxxxxxxxx,	virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx, chegu_vinod@xxxxxx,	david.vrabel@xxxxxxxxxx, oleg@xxxxxxxxxx,	xen-devel@xxxxxxxxxxxxxxxxxxxx, boris.ostrovsky@xxxxxxxxxx,	paulmck@xxxxxxxxxxxxxxxxxx, torvalds@xxxxxxxxxxxxxxxxxxxxDelivery-date: Wed, 18 Jun 2014 11:40:51 +0000List-id: Xen developer discussion <xen-devel.lists.xen.org> 
 
Il 15/06/2014 14:47, Peter Zijlstra ha scritto:
 
-       for (;;) {
-               new = (val & ~_Q_PENDING_MASK) | _Q_LOCKED_VAL;
-
-               old = atomic_cmpxchg(&lock->val, val, new);
-               if (old == val)
-                       break;
-
-               val = old;
-       }
+       clear_pending_set_locked(lock, val);
        return;
 
Might as well add clear_pending_set_locked already in patch 3.
Paolo
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