linux-kernel - [PATCH v2 4/4] x86/kvm/hyper-v: avoid open-coding stimer_mark_pending() in kvm_hv_notify_acked

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Message-Id: <20181126154732.23025-5-vkuznets@redhat.com>
Date:   Mon, 26 Nov 2018 16:47:32 +0100
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     kvm@...r.kernel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>,
        linux-kernel@...r.kernel.org, Roman Kagan <rkagan@...tuozzo.com>,
        "K. Y. Srinivasan" <kys@...rosoft.com>,
        Haiyang Zhang <haiyangz@...rosoft.com>,
        Stephen Hemminger <sthemmin@...rosoft.com>, x86@...nel.org,
        "Michael Kelley (EOSG)" <Michael.H.Kelley@...rosoft.com>
Subject: [PATCH v2 4/4] x86/kvm/hyper-v: avoid open-coding stimer_mark_pending() in kvm_hv_notify_acked_sint()

stimers_pending optimization only helps us to avoid multiple
kvm_make_request() calls. This doesn't happen very often and these
calls are very cheap in the first place, remove open-coded version of
stimer_mark_pending() from kvm_hv_notify_acked_sint().

Suggested-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
---
 arch/x86/kvm/hyperv.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 9533133be566..e6a2a085644a 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -206,7 +206,7 @@ static void kvm_hv_notify_acked_sint(struct kvm_vcpu *vcpu, u32 sint)
 	struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
 	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
 	struct kvm_vcpu_hv_stimer *stimer;
-	int gsi, idx, stimers_pending;
+	int gsi, idx;
 
 	trace_kvm_hv_notify_acked_sint(vcpu->vcpu_id, sint);
 
@@ -214,19 +214,13 @@ static void kvm_hv_notify_acked_sint(struct kvm_vcpu *vcpu, u32 sint)
 		synic_clear_sint_msg_pending(synic, sint);
 
 	/* Try to deliver pending Hyper-V SynIC timers messages */
-	stimers_pending = 0;
 	for (idx = 0; idx < ARRAY_SIZE(hv_vcpu->stimer); idx++) {
 		stimer = &hv_vcpu->stimer[idx];
 		if (stimer->msg_pending && stimer->config.enable &&
 		    !stimer->config.direct_mode &&
-		    stimer->config.sintx == sint) {
-			set_bit(stimer->index,
-				hv_vcpu->stimer_pending_bitmap);
-			stimers_pending++;
-		}
+		    stimer->config.sintx == sint)
+			stimer_mark_pending(stimer, false);
 	}
-	if (stimers_pending)
-		kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
 
 	idx = srcu_read_lock(&kvm->irq_srcu);
 	gsi = atomic_read(&synic->sint_to_gsi[sint]);
-- 
2.19.1