From: Waiman Long <longman@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
Will Deacon <will.deacon@arm.com>, Joe Mario <jmario@redhat.com>,
Waiman Long <longman@redhat.com>
Subject: [PATCH] x86/pvqspinlock: Use LOCK_PREFIX in __pv_queued_spin_unlock assembly code
Date: Tue, 17 Jul 2018 16:16:00 -0400 [thread overview]
Message-ID: <1531858560-21547-1-git-send-email-longman@redhat.com> (raw)
The LOCK_PREFIX macro should be used in the assembly
__raw_callee_save___pv_queued_spin_unlock code so that the lock prefix
can be patched out on UP systems.
Signed-off-by: Waiman Long <longman@redhat.com>
---
arch/x86/include/asm/qspinlock_paravirt.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/qspinlock_paravirt.h b/arch/x86/include/asm/qspinlock_paravirt.h
index 9ef5ee0..159622e 100644
--- a/arch/x86/include/asm/qspinlock_paravirt.h
+++ b/arch/x86/include/asm/qspinlock_paravirt.h
@@ -43,7 +43,7 @@
"push %rdx;"
"mov $0x1,%eax;"
"xor %edx,%edx;"
- "lock cmpxchg %dl,(%rdi);"
+ LOCK_PREFIX "cmpxchg %dl,(%rdi);"
"cmp $0x1,%al;"
"jne .slowpath;"
"pop %rdx;"
--
1.8.3.1
next reply other threads:[~2018-07-17 20:16 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-17 20:16 Waiman Long [this message]
2018-07-18 8:19 ` [PATCH] x86/pvqspinlock: Use LOCK_PREFIX in __pv_queued_spin_unlock assembly code Peter Zijlstra
2018-07-18 13:28 ` Waiman Long
2018-07-25 14:20 ` [tip:locking/urgent] locking/pvqspinlock/x86: Use LOCK_PREFIX in __pv_queued_spin_unlock() " tip-bot for Waiman Long
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