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From: Wanpeng Li <kernellwp@gmail.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>
Subject: [PATCH v3 0/3] KVM: Introduce dedicated vCPUs hint KVM_HINTS_DEDICATED
Date: Sun, 11 Feb 2018 11:29:43 +0800	[thread overview]
Message-ID: <1518319786-1466-1-git-send-email-wanpengli@tencent.com> (raw)

This patchset introduces dedicated vCPUs hint KVM_HINTS_DEDICATED, it 
has two users now:

1) Waiman Long mentioned that:

    Generally speaking, unfair lock performs well for VMs with a small
    number of vCPUs. Native qspinlock may perform better than pvqspinlock
    if there is vCPU pinning and there is no vCPU over-commitment.

2) vCPUs are very unlikely to get preempted when they are the only task 
   running on a CPU. PV TLB flush is slower that the native flush in that 
   case.

v2 -> v3:
 * a separate table for CPUID[0x40000001].EDX bits
 * a new kvm_hint_has_feature macro
v1 -> v2:
 * update to KVM_HINTS_DEDICATED

Wanpeng Li (3):
  KVM: Introduce dedicated vCPUs hint KVM_HINTS_DEDICATED
  KVM: X86: Choose qspinlock when dedicated vCPUs available
  KVM: X86: Don't use PV TLB flush with dedicated vCPUs and steal time
    disabled

 Documentation/virtual/kvm/cpuid.txt  | 12 +++++++++++-
 arch/mips/include/asm/kvm_para.h     |  5 +++++
 arch/powerpc/include/asm/kvm_para.h  |  5 +++++
 arch/s390/include/asm/kvm_para.h     |  5 +++++
 arch/x86/include/asm/kvm_para.h      |  6 ++++++
 arch/x86/include/uapi/asm/kvm_para.h |  8 ++++++--
 arch/x86/kernel/kvm.c                | 18 ++++++++++++++++--
 include/asm-generic/kvm_para.h       |  5 +++++
 include/linux/kvm_para.h             |  5 +++++
 9 files changed, 64 insertions(+), 5 deletions(-)

-- 
2.7.4

             reply	other threads:[~2018-02-11  3:29 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-11  3:29 Wanpeng Li [this message]
2018-02-11  3:29 ` [PATCH v3 1/3] KVM: Introduce dedicated vCPUs hint KVM_HINTS_DEDICATED Wanpeng Li
2018-02-12  9:38   ` Andrew Jones
2018-02-12 14:12   ` Eduardo Habkost
2018-02-13  1:09     ` Wanpeng Li
2018-02-11  3:29 ` [PATCH v3 2/3] KVM: X86: Choose qspinlock when dedicated vCPUs available Wanpeng Li
2018-02-11  3:29 ` [PATCH v3 3/3] KVM: X86: Don't use PV TLB flush with dedicated vCPUs and steal time disabled Wanpeng Li

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