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From: Avi Kivity <avi@qumranet.com>
To: kvm-devel@lists.sourceforge.net
Cc: linux-kernel@vger.kernel.org, Eddie Dong <eddie.dong@intel.com>,
	Avi Kivity <avi@qumranet.com>
Subject: [PATCH 14/18] KVM: VMX: Avoid unnecessary vcpu_load()/vcpu_put() cycles
Date: Thu, 26 Apr 2007 12:22:14 +0300	[thread overview]
Message-ID: <1177579338397-git-send-email-avi@qumranet.com> (raw)
In-Reply-To: <11775793382353-git-send-email-avi@qumranet.com>

From: Eddie Dong <eddie.dong@intel.com>

By checking if a reschedule is needed, we avoid dropping the vcpu.

[With changes by me, based on Anthony Liguori's observations]

Signed-off-by: Avi Kivity <avi@qumranet.com>
---
 drivers/kvm/kvm_main.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 03c0ee7..f535635 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1590,6 +1590,8 @@ static int set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
 
 void kvm_resched(struct kvm_vcpu *vcpu)
 {
+	if (!need_resched())
+		return;
 	vcpu_put(vcpu);
 	cond_resched();
 	vcpu_load(vcpu);
-- 
1.5.0.6


  parent reply	other threads:[~2007-04-26  9:24 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-04-26  9:22 [PATCH 00/18] KVM updates for 2.6.22 Avi Kivity
2007-04-26  9:22 ` [PATCH 01/18] KVM: Use kernel-standard types Avi Kivity
2007-04-26  9:22 ` [PATCH 02/18] KVM: Fix overflow bug in overflow detection code Avi Kivity
2007-04-26  9:22 ` [PATCH 03/18] KVM: Initialize cr0 to indicate an fpu is present Avi Kivity
2007-04-26  9:22 ` [PATCH 04/18] KVM: Handle partial pae pdptr Avi Kivity
2007-04-26  9:22 ` [PATCH 05/18] KVM: Use slab caches to allocate mmu data structures Avi Kivity
2007-04-26  9:22 ` [PATCH 06/18] KVM: Retry sleeping allocation if atomic allocation fails Avi Kivity
2007-04-26  9:22 ` [PATCH 07/18] KVM: SVM: Report hardware exit reason to userspace instead of dmesg Avi Kivity
2007-04-26  9:22 ` [PATCH 08/18] KVM: Handle guest page faults when emulating mmio Avi Kivity
2007-04-26  9:22 ` [PATCH 09/18] KVM: VMX: Reduce unnecessary saving of host msrs Avi Kivity
2007-04-26  9:22 ` [PATCH 10/18] KVM: VMX: Don't switch 64-bit msrs for 32-bit guests Avi Kivity
2007-04-26  9:22 ` [PATCH 11/18] KVM: Fold drivers/kvm/kvm_vmx.h into drivers/kvm/vmx.c Avi Kivity
2007-04-26  9:22 ` [PATCH 12/18] KVM: VMX: Only save/restore MSR_K6_STAR if necessary Avi Kivity
2007-04-26  9:22 ` [PATCH 13/18] KVM: MMU: Avoid heavy ASSERT at non debug mode Avi Kivity
2007-04-26  9:22 ` Avi Kivity [this message]
2007-04-26  9:22 ` [PATCH 15/18] KVM: Per-vcpu statistics Avi Kivity
2007-04-26  9:22 ` [PATCH 16/18] KVM: Allow passing 64-bit values to the emulated read/write API Avi Kivity
2007-04-26  9:22 ` [PATCH 17/18] KVM: Lazy FPU support for SVM Avi Kivity
2007-04-26  9:22 ` [PATCH 18/18] KVM: Don't complain about cpu erratum AA15 Avi Kivity

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