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From: Davidlohr Bueso <dave@stgolabs.net>
To: mingo@redhat.com, peterz@infradead.org, pbonzini@redhat.com
Cc: npiggin@gmail.com, paulmck@linux.vnet.ibm.com, dave@stgolabs.net,
	linux-kernel@vger.kernel.org, Davidlohr Bueso <dbueso@suse.de>
Subject: [PATCH 6/6] kvm,powerpc: Serialize wq active checks in ops->vcpu_kick
Date: Tue,  5 Sep 2017 12:00:22 -0700	[thread overview]
Message-ID: <20170905190022.1474-7-dave@stgolabs.net> (raw)
In-Reply-To: <20170905190022.1474-1-dave@stgolabs.net>

Particularly because kvmppc_fast_vcpu_kick_hv() is a callback,
ensure that we properly serialize wq active checks in order to
avoid potentially missing a wakeup due to racing with the waiter
side.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
 arch/powerpc/kvm/book3s_hv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 359c79cdf0cc..7ffc757ef978 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -181,7 +181,7 @@ static void kvmppc_fast_vcpu_kick_hv(struct kvm_vcpu *vcpu)
 	struct swait_queue_head *wqp;
 
 	wqp = kvm_arch_vcpu_wq(vcpu);
-	if (swait_active(wqp)) {
+	if (swq_has_sleeper(wqp)) {
 		swake_up(wqp);
 		++vcpu->stat.halt_wakeup;
 	}
-- 
2.12.0

      parent reply	other threads:[~2017-09-05 19:01 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-05 19:00 [PATCH 0/6] swait: Introduce and use swq_has_sleepers Davidlohr Bueso
2017-09-05 19:00 ` [PATCH 1/6] sched/wait: Add swq_has_sleepers() Davidlohr Bueso
2017-10-11  8:27   ` Peter Zijlstra
2017-10-11 11:21     ` Paolo Bonzini
2017-10-11 11:29       ` Peter Zijlstra
2017-09-05 19:00 ` [PATCH 2/6] kvm,async_pf: Use swq_has_sleepers() Davidlohr Bueso
2017-09-05 19:00 ` [PATCH 3/6] kvm,lapic: Justify use of swait_activate() Davidlohr Bueso
2017-09-05 19:00 ` [PATCH 4/6] x86,kvm: Fix apf_task_wake_one() serialization Davidlohr Bueso
2017-09-10  9:20   ` Paolo Bonzini
2017-09-10  9:24     ` Paolo Bonzini
2017-10-12  8:23       ` Peter Zijlstra
2017-09-05 19:00 ` [PATCH 5/6] kvm: Serialize wq active checks in kvm_vcpu_wake_up() Davidlohr Bueso
2017-09-05 19:00 ` Davidlohr Bueso [this message]

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