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From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: kvm@vger.kernel.org
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	linux-kernel@vger.kernel.org,
	"Roman Kagan" <rkagan@virtuozzo.com>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	"Haiyang Zhang" <haiyangz@microsoft.com>,
	"Stephen Hemminger" <sthemmin@microsoft.com>,
	x86@kernel.org,
	"Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com>
Subject: [PATCH v2 4/4] x86/kvm/hyper-v: avoid open-coding stimer_mark_pending() in kvm_hv_notify_acked_sint()
Date: Mon, 26 Nov 2018 16:47:32 +0100	[thread overview]
Message-ID: <20181126154732.23025-5-vkuznets@redhat.com> (raw)
In-Reply-To: <20181126154732.23025-1-vkuznets@redhat.com>

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@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.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


  parent reply	other threads:[~2018-11-26 15:47 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-26 15:47 [PATCH v2 0/4] x86/kvm/hyper-v: Implement Direct Mode for synthetic timers Vitaly Kuznetsov
2018-11-26 15:47 ` [PATCH v2 1/4] x86/hyper-v: move synic/stimer control structures definitions to hyperv-tlfs.h Vitaly Kuznetsov
2018-11-26 17:00   ` Michael Kelley
2018-11-26 20:04   ` Roman Kagan
2018-11-27 13:10     ` Vitaly Kuznetsov
2018-11-27 15:52       ` Michael Kelley
2018-11-27 16:32         ` Vitaly Kuznetsov
2018-11-27 18:48       ` Roman Kagan
2018-11-28  1:49         ` Nadav Amit
2018-11-28 10:37           ` Vitaly Kuznetsov
2018-11-28 13:07             ` Thomas Gleixner
2018-11-28 17:55               ` Nadav Amit
2018-11-29 11:36                 ` Vitaly Kuznetsov
2018-11-29 19:22                   ` Thomas Gleixner
2018-11-29  7:52               ` Roman Kagan
2018-11-28  8:40         ` Paolo Bonzini
2018-11-26 15:47 ` [PATCH v2 2/4] x86/kvm/hyper-v: use stimer config definition from hyperv-tlfs.h Vitaly Kuznetsov
2018-11-26 15:47 ` [PATCH v2 3/4] x86/kvm/hyper-v: direct mode for synthetic timers Vitaly Kuznetsov
2018-11-26 16:44   ` Paolo Bonzini
2018-11-26 17:14     ` Vitaly Kuznetsov
2018-11-27  8:37     ` Roman Kagan
2018-11-27 13:54       ` Paolo Bonzini
2018-11-27 19:05         ` Roman Kagan
2018-11-28  8:43           ` Paolo Bonzini
2018-11-27  8:21   ` Roman Kagan
2018-12-03 17:12   ` Roman Kagan
2018-12-04 12:36     ` Vitaly Kuznetsov
2018-12-10 12:06   ` Roman Kagan
2018-12-10 12:54     ` Vitaly Kuznetsov
2018-12-10 13:21       ` Roman Kagan
2018-12-10 14:53         ` Vitaly Kuznetsov
2018-11-26 15:47 ` Vitaly Kuznetsov [this message]
2018-11-26 16:45   ` [PATCH v2 4/4] x86/kvm/hyper-v: avoid open-coding stimer_mark_pending() in kvm_hv_notify_acked_sint() Paolo Bonzini
2018-11-27  8:49   ` Roman Kagan
2018-11-26 16:45 ` [PATCH v2 0/4] x86/kvm/hyper-v: Implement Direct Mode for synthetic timers Paolo Bonzini

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