Commit a6b27785 authored Sep 05, 2015 by Peter Zijlstra Committed by Ingo Molnar Sep 11, 2015

locking/qspinlock/x86: Only emit the test-and-set fallback when building guest support



Only emit the test-and-set fallback for Hypervisors lacking
PARAVIRT_SPINLOCKS support when building for guests.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # 4.2
Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 43b3f028

arch/x86/include/asm/qspinlock.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -39,8 +39,8 @@ static inline void queued_spin_unlock(struct qspinlock *lock)
		}
		#endif

		#ifdef CONFIG_PARAVIRT
		#define virt_spin_lock virt_spin_lock

		static inline bool virt_spin_lock(struct qspinlock *lock)
		{
		if (!static_cpu_has(X86_FEATURE_HYPERVISOR))
		@@ -59,6 +59,7 @@ static inline bool virt_spin_lock(struct qspinlock *lock)

		return true;
		}
		#endif /* CONFIG_PARAVIRT */

		#include <asm-generic/qspinlock.h>