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From: "Radim Krčmář" <rkrcmar@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: David Matlack <dmatlack@google.com>,
	Yunhong Jiang <yunhong.jiang@linux.intel.com>,
	kvm list <kvm@vger.kernel.org>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	Wanpeng Li <kernellwp@gmail.com>
Subject: Re: [RFC PATCH V2 4/4] Utilize the vmx preemption timer for tsc deadline timer
Date: Wed, 25 May 2016 15:38:57 +0200	[thread overview]
Message-ID: <20160525133857.GB14795@potion> (raw)
In-Reply-To: <3d6068c4-34b8-fe23-9107-13eac6be0b41@redhat.com>

2016-05-25 12:40+0200, Paolo Bonzini:
> On 25/05/2016 01:11, David Matlack wrote:
>> > However, it possibly has impact if the vCPU thread is scheduled in/out
>> > very frequently, because it switches from/to the hrtimer emulation a lot.
>> 
>> What is the cost of the extra sched-in/out hooks?
> 
> I still have to review this version of the patches, but I think they can
> be removed and moved to blocking/unblocking instead.

I this so as well.  hrtimer does not make a difference to a preempted
VCPU or VCPU in userspace, only the blocking sleep needs to be
interrupted.

  reply	other threads:[~2016-05-25 13:39 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-24 22:27 [RFC PATCH V2 0/4] Utilizing VMX preemption for timer virtualization Yunhong Jiang
2016-05-24 22:27 ` [RFC PATCH V2 1/4] Add the kvm sched_out hook Yunhong Jiang
2016-05-24 22:27 ` [RFC PATCH V2 2/4] Utilize the vmx preemption timer Yunhong Jiang
2016-06-14 13:23   ` Roman Kagan
2016-06-14 13:41     ` Paolo Bonzini
2016-06-14 16:46       ` yunhong jiang
2016-06-14 21:56         ` Paolo Bonzini
2016-06-15 18:03           ` yunhong jiang
2016-06-14 16:46     ` yunhong jiang
2016-05-24 22:27 ` [RFC PATCH V2 3/4] Separate the start_sw_tscdeadline Yunhong Jiang
2016-05-24 22:27 ` [RFC PATCH V2 4/4] Utilize the vmx preemption timer for tsc deadline timer Yunhong Jiang
2016-05-24 23:11   ` David Matlack
2016-05-24 23:35     ` yunhong jiang
2016-05-25 11:58       ` Paolo Bonzini
2016-05-25 22:53         ` yunhong jiang
2016-05-26  7:20           ` Paolo Bonzini
2016-05-25 10:40     ` Paolo Bonzini
2016-05-25 13:38       ` Radim Krčmář [this message]
2016-05-25 11:52   ` Paolo Bonzini
2016-05-25 22:44     ` yunhong jiang
2016-05-26 14:05       ` Alan Jenkins
2016-05-26 15:32         ` Paolo Bonzini
2016-06-04  0:24     ` yunhong jiang
2016-06-06 13:49       ` Paolo Bonzini
2016-06-06 18:21         ` yunhong jiang
2016-05-25 13:27   ` Radim Krčmář
2016-05-25 13:51     ` Paolo Bonzini
2016-05-25 14:31       ` Radim Krčmář
2016-05-25 23:13         ` yunhong jiang
2016-06-14 11:34         ` Paolo Bonzini
2016-05-25 13:45   ` Radim Krčmář
2016-05-25 22:57     ` yunhong jiang

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