From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Waiman Long <Waiman.Long@hp.com>
Cc: linux-arch@vger.kernel.org, Rik van Riel <riel@redhat.com>,
Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>,
kvm@vger.kernel.org, Oleg Nesterov <oleg@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Scott J Norton <scott.norton@hp.com>,
x86@kernel.org, Paolo Bonzini <paolo.bonzini@gmail.com>,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org,
Ingo Molnar <mingo@redhat.com>,
David Vrabel <david.vrabel@citrix.com>,
"H. Peter Anvin" <hpa@zytor.com>,
xen-devel@lists.xenproject.org,
Thomas Gleixner <tglx@linutronix.de>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Douglas Hatch <doug.hatch@hp.com>
Subject: Re: [PATCH v13 10/11] pvqspinlock, x86: Enable PV qspinlock for KVM
Date: Tue, 2 Dec 2014 14:10:58 -0500 [thread overview]
Message-ID: <20141202191058.GA357@laptop.dumpdata.com> (raw)
In-Reply-To: <1414613951-32532-11-git-send-email-Waiman.Long@hp.com>
On Wed, Oct 29, 2014 at 04:19:10PM -0400, Waiman Long wrote:
> This patch adds the necessary KVM specific code to allow KVM to
> support the CPU halting and kicking operations needed by the queue
> spinlock PV code.
>
> Two KVM guests of 20 CPU cores (2 nodes) were created for performance
> testing in one of the following three configurations:
> 1) Only 1 VM is active
> 2) Both VMs are active and they share the same 20 physical CPUs
> (200% overcommit)
>
> The tests run included the disk workload of the AIM7 benchmark on
> both ext4 and xfs RAM disks at 3000 users on a 3.17 based kernel. The
> "ebizzy -m" test and futextest was was also run and its performance
> data were recorded. With two VMs running, the "idle=poll" kernel
> option was added to simulate a busy guest. If PV qspinlock is not
> enabled, unfairlock will be used automically in a guest.
What is the unfairlock? Isn't it just using a bytelock at this point?
WARNING: multiple messages have this Message-ID (diff)
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Waiman Long <Waiman.Long@hp.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>,
Scott J Norton <scott.norton@hp.com>,
Douglas Hatch <doug.hatch@hp.com>
Subject: Re: [PATCH v13 10/11] pvqspinlock, x86: Enable PV qspinlock for KVM
Date: Tue, 2 Dec 2014 14:10:58 -0500 [thread overview]
Message-ID: <20141202191058.GA357@laptop.dumpdata.com> (raw)
Message-ID: <20141202191058.CgHEC4wF-BRZTP8t4fNadB6pz9nQP5EPvc6u-cbzhZg@z> (raw)
In-Reply-To: <1414613951-32532-11-git-send-email-Waiman.Long@hp.com>
On Wed, Oct 29, 2014 at 04:19:10PM -0400, Waiman Long wrote:
> This patch adds the necessary KVM specific code to allow KVM to
> support the CPU halting and kicking operations needed by the queue
> spinlock PV code.
>
> Two KVM guests of 20 CPU cores (2 nodes) were created for performance
> testing in one of the following three configurations:
> 1) Only 1 VM is active
> 2) Both VMs are active and they share the same 20 physical CPUs
> (200% overcommit)
>
> The tests run included the disk workload of the AIM7 benchmark on
> both ext4 and xfs RAM disks at 3000 users on a 3.17 based kernel. The
> "ebizzy -m" test and futextest was was also run and its performance
> data were recorded. With two VMs running, the "idle=poll" kernel
> option was added to simulate a busy guest. If PV qspinlock is not
> enabled, unfairlock will be used automically in a guest.
What is the unfairlock? Isn't it just using a bytelock at this point?
next prev parent reply other threads:[~2014-12-02 19:10 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-29 20:19 [PATCH v13 00/11] qspinlock: a 4-byte queue spinlock with PV support Waiman Long
2014-10-29 20:19 ` Waiman Long
2014-10-29 20:19 ` [PATCH v13 01/11] qspinlock: A simple generic 4-byte queue spinlock Waiman Long
2014-10-29 20:19 ` Waiman Long
2014-10-29 20:19 ` [PATCH v13 02/11] qspinlock, x86: Enable x86-64 to use " Waiman Long
2014-10-29 20:19 ` Waiman Long
2014-10-29 20:19 ` [PATCH v13 03/11] qspinlock: Add pending bit Waiman Long
2014-10-29 20:19 ` Waiman Long
2014-10-29 20:19 ` [PATCH v13 04/11] qspinlock: Extract out code snippets for the next patch Waiman Long
2014-10-29 20:19 ` Waiman Long
2014-10-29 20:19 ` [PATCH v13 05/11] qspinlock: Optimize for smaller NR_CPUS Waiman Long
2014-10-29 20:19 ` Waiman Long
2014-10-29 20:19 ` [PATCH v13 06/11] qspinlock: Use a simple write to grab the lock Waiman Long
2014-10-29 20:19 ` Waiman Long
2014-10-29 20:19 ` [PATCH v13 07/11] qspinlock: Revert to test-and-set on hypervisors Waiman Long
2014-10-29 20:19 ` Waiman Long
2014-10-29 20:19 ` [PATCH v13 08/11] qspinlock, x86: Rename paravirt_ticketlocks_enabled Waiman Long
2014-10-29 20:19 ` Waiman Long
2014-10-29 20:19 ` [PATCH v13 09/11] pvqspinlock, x86: Add para-virtualization support Waiman Long
2014-10-29 20:19 ` Waiman Long
2014-11-03 10:35 ` Peter Zijlstra
2014-11-03 10:35 ` Peter Zijlstra
2014-11-03 21:17 ` Waiman Long
2014-11-03 21:17 ` Waiman Long
2014-12-01 16:40 ` Konrad Rzeszutek Wilk
2014-12-01 16:40 ` Konrad Rzeszutek Wilk
2014-10-29 20:19 ` [PATCH v13 10/11] pvqspinlock, x86: Enable PV qspinlock for KVM Waiman Long
2014-10-29 20:19 ` Waiman Long
2014-12-02 19:10 ` Konrad Rzeszutek Wilk [this message]
2014-12-02 19:10 ` Konrad Rzeszutek Wilk
2014-12-03 0:40 ` Thomas Gleixner
2014-12-03 0:40 ` Thomas Gleixner
2014-10-29 20:19 ` [PATCH v13 11/11] pvqspinlock, x86: Enable PV qspinlock for XEN Waiman Long
2014-10-29 20:19 ` Waiman Long
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