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From: Waiman Long <waiman.long@hp.com>
To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	Peter Zijlstra <peterz@infradead.org>,
	linux-arch@vger.kernel.org, x86@kernel.org,
	linux-kernel@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	xen-devel@lists.xenproject.org, kvm@vger.kernel.org,
	Paolo Bonzini <paolo.bonzini@gmail.com>,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Rik van Riel <riel@redhat.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>,
	David Vrabel <david.vrabel@citrix.com>,
	Oleg Nesterov <oleg@redhat.com>, Gleb Natapov <gleb@redhat.com>,
	Scott J Norton <scott.norton@hp.com>,
	Chegu Vinod <chegu_vinod@hp.com>
Subject: Re: [PATCH v10 18/19] pvqspinlock, x86: Enable PV qspinlock PV for KVM
Date: Thu, 08 May 2014 13:54:07 -0400	[thread overview]
Message-ID: <536BC4BF.9030603@hp.com> (raw)
In-Reply-To: <20140507190706.GA16333@phenom.dumpdata.com>

On 05/07/2014 03:07 PM, Konrad Rzeszutek Wilk wrote:
>> Raghavendra KT had done some performance testing on this patch with
>> the following results:
>>
>> Overall we are seeing good improvement for pv-unfair version.
>>
>> System: 32 cpu sandybridge with HT on (4 node with 32 GB each)
>> Guest : 8GB with 16 vcpu/VM.
>> Average was taken over 8-10 data points.
>>
>> Base = 3.15-rc2  with PRAVIRT_SPINLOCK = y
>>
>> A = 3.15-rc2 + qspinlock v9 patch with QUEUE_SPINLOCK = y
>> PRAVIRT_SPINLOCK = y PARAVIRT_UNFAIR_LOCKS = y (unfair lock)
>>
>> B =  3.15-rc2 + qspinlock v9 patch with QUEUE_SPINLOCK = y
>> PRAVIRT_SPINLOCK = n PARAVIRT_UNFAIR_LOCKS = n
>> (queue spinlock without paravirt)
>>
>> C = 3.15-rc2 + qspinlock v9 patch with  QUEUE_SPINLOCK = y
>> PRAVIRT_SPINLOCK = y  PARAVIRT_UNFAIR_LOCKS = n
>> (queue spinlock with paravirt)
> Could you do s/PRAVIRT/PARAVIRT/ please?
>

Sorry for the typo, I didn't check the text carefully enough when I 
cut-and-paste it from Raghavendra's email.

>> Ebizzy %improvements
>> ====================
>> overcommit  A            B            C
>> 0.5x     4.4265        2.0611       1.5824
>> 1.0x     0.9015       -7.7828       4.5443
>> 1.5x    46.1162       -2.9845      -3.5046
>> 2.0x    99.8150       -2.7116       4.7461
> Considering B sucks

Yes, I don't expect the plain qspinlock code will perform well in a 
guest without either unfair or pvspinlock support.

-Longman

  reply	other threads:[~2014-05-08 17:54 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-07 15:01 [PATCH v10 00/19] qspinlock: a 4-byte queue spinlock with PV support Waiman Long
2014-05-07 15:01 ` [PATCH v10 01/19] qspinlock: A simple generic 4-byte queue spinlock Waiman Long
2014-05-07 15:01 ` [PATCH v10 02/19] qspinlock, x86: Enable x86-64 to use " Waiman Long
2014-05-07 15:01 ` [PATCH v10 03/19] qspinlock: Add pending bit Waiman Long
2014-05-08 18:57   ` Peter Zijlstra
2014-05-10  0:49     ` Waiman Long
2014-05-12 15:22   ` Radim Krčmář
2014-05-12 17:29     ` Peter Zijlstra
2014-05-13 19:47     ` Waiman Long
2014-05-14 16:51       ` Radim Krčmář
2014-05-14 17:00         ` Peter Zijlstra
2014-05-14 19:13           ` Radim Krčmář
2014-05-19 20:17             ` Waiman Long
     [not found]               ` <20140521164930.GA26199@potion.brq.redhat.com>
2014-05-21 17:02                 ` [RFC 08/07] qspinlock: integrate pending bit into queue Radim Krčmář
2014-05-07 15:01 ` [PATCH v10 04/19] qspinlock: Extract out the exchange of tail code word Waiman Long
2014-05-07 15:01 ` [PATCH v10 05/19] qspinlock: Optimize for smaller NR_CPUS Waiman Long
2014-05-07 15:01 ` [PATCH v10 06/19] qspinlock: prolong the stay in the pending bit path Waiman Long
2014-05-08 18:58   ` Peter Zijlstra
2014-05-10  0:58     ` Waiman Long
2014-05-10 13:38       ` Peter Zijlstra
2014-05-07 15:01 ` [PATCH v10 07/19] qspinlock: Use a simple write to grab the lock, if applicable Waiman Long
2014-05-08 19:00   ` Peter Zijlstra
2014-05-10  1:05     ` Waiman Long
2014-05-08 19:02   ` Peter Zijlstra
2014-05-10  1:06     ` Waiman Long
2014-05-07 15:01 ` [PATCH v10 08/19] qspinlock: Make a new qnode structure to support virtualization Waiman Long
2014-05-08 19:04   ` Peter Zijlstra
2014-05-10  1:08     ` Waiman Long
2014-05-10 14:14       ` Peter Zijlstra
2014-05-10 18:21         ` Peter Zijlstra
2014-05-07 15:01 ` [PATCH v10 09/19] qspinlock: Prepare for unfair lock support Waiman Long
2014-05-08 19:06   ` Peter Zijlstra
2014-05-10  1:19     ` Waiman Long
2014-05-10 14:13       ` Peter Zijlstra
2014-05-07 15:01 ` [PATCH v10 10/19] qspinlock, x86: Allow unfair spinlock in a virtual guest Waiman Long
2014-05-08 19:12   ` Peter Zijlstra
2014-05-19 20:30     ` Waiman Long
2014-05-12 18:57   ` Radim Krčmář
2014-05-07 15:01 ` [PATCH v10 11/19] qspinlock: Split the MCS queuing code into a separate slowerpath Waiman Long
2014-05-07 15:01 ` [PATCH v10 12/19] unfair qspinlock: Variable frequency lock stealing mechanism Waiman Long
2014-05-08 19:19   ` Peter Zijlstra
2014-05-07 15:01 ` [PATCH v10 13/19] unfair qspinlock: Enable lock stealing in lock waiters Waiman Long
2014-05-07 15:01 ` [PATCH v10 14/19] pvqspinlock, x86: Rename paravirt_ticketlocks_enabled Waiman Long
2014-05-07 15:01 ` [PATCH v10 15/19] pvqspinlock, x86: Add PV data structure & methods Waiman Long
2014-05-07 15:01 ` [PATCH v10 16/19] pvqspinlock: Enable coexistence with the unfair lock Waiman Long
2014-05-07 15:01 ` [PATCH v10 17/19] pvqspinlock: Add qspinlock para-virtualization support Waiman Long
2014-05-07 15:01 ` [PATCH v10 18/19] pvqspinlock, x86: Enable PV qspinlock PV for KVM Waiman Long
2014-05-07 19:07   ` Konrad Rzeszutek Wilk
2014-05-08 17:54     ` Waiman Long [this message]
2014-05-07 15:01 ` [PATCH v10 19/19] pvqspinlock, x86: Enable PV qspinlock for XEN Waiman Long
2014-05-07 19:07 ` [PATCH v10 00/19] qspinlock: a 4-byte queue spinlock with PV support Konrad Rzeszutek Wilk
2014-05-08 17:54   ` Waiman Long

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