From: Davidlohr Bueso <dave@stgolabs.net>
To: mingo@kernel.org, peterz@infradead.org, pbonzini@redhat.com
Cc: npiggin@gmail.com, paulmck@linux.vnet.ibm.com,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
dave@stgolabs.net, Davidlohr Bueso <dbueso@suse.de>
Subject: [PATCH 5/7] kvm: Serialize wq active checks in kvm_vcpu_wake_up()
Date: Wed, 13 Sep 2017 13:08:22 -0700 [thread overview]
Message-ID: <20170913200824.28067-6-dave@stgolabs.net> (raw)
In-Reply-To: <20170913200824.28067-1-dave@stgolabs.net>
This is a generic call and can be suceptible to races
in reading the wq task_list while another task is adding
itself to the list. Add a full barrier by using the
swq_has_sleeper() helper.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
virt/kvm/kvm_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 6ed1c2021198..c41d903c5783 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2186,7 +2186,7 @@ bool kvm_vcpu_wake_up(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;
return true;
--
2.12.0
next prev parent reply other threads:[~2017-09-13 20:09 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-13 20:08 [PATCH v2 0/7] swait: Introduce and use swq_has_sleeper() Davidlohr Bueso
2017-09-13 20:08 ` [PATCH 1/7] sched/wait: Add swq_has_sleepers() Davidlohr Bueso
2017-09-13 20:08 ` [PATCH 2/7] kvm,async_pf: Use swq_has_sleepers() Davidlohr Bueso
2017-09-13 20:08 ` [PATCH 3/7] kvm,lapic: Justify use of swait_activate() Davidlohr Bueso
2017-09-15 11:47 ` Paolo Bonzini
2017-09-13 20:08 ` [PATCH 4/7] kvm,x86: Fix apf_task_wake_one() wq serialization Davidlohr Bueso
2017-09-13 20:08 ` Davidlohr Bueso [this message]
2017-09-13 20:08 ` [PATCH 6/7] kvm,powerpc: Serialize wq active checks in ops->vcpu_kick Davidlohr Bueso
2017-09-13 20:08 ` [PATCH 7/7] kvm,mips: Fix potential swait_active() races Davidlohr Bueso
2017-09-13 20:35 ` Paolo Bonzini
2017-09-13 22:22 ` Davidlohr Bueso
2017-09-15 11:33 ` Paolo Bonzini
2017-09-15 11:53 ` [PATCH v2 0/7] swait: Introduce and use swq_has_sleeper() Paolo Bonzini
2017-09-19 8:25 ` Christian Borntraeger
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