From: Paolo Bonzini <pbonzini@redhat.com>
To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>,
Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>,
kvm@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>,
virtualization@lists.linux-foundation.org,
Andi Kleen <andi@firstfloor.org>,
"H. Peter Anvin" <hpa@zytor.com>,
Michel Lespinasse <walken@google.com>,
Alok Kataria <akataria@vmware.com>,
linux-arch@vger.kernel.org, Gleb Natapov <gleb@redhat.com>,
x86@kernel.org, Ingo Molnar <mingo@redhat.com>,
xen-devel@lists.xenproject.org,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Rik van Riel <riel@redhat.com>, Arnd Bergmann <arnd@arndb.de>,
Scott J Norton <scott.norton@hp.com>,
Steven Rostedt <rostedt@goodmis.org>,
Chris Wright <chrisw@sous-sol.org>,
Thomas Gleixner <tglx@linutronix.de>,
Aswin Chandramouleeswaran <aswin@hp.com>,
Chegu Vinod <chegu_vinod@hp.com>,
Waiman Long <Waiman.Long@hp.com>, Oleg Nesterov <oleg@redhat.com>
Subject: Re: [PATCH v6 05/11] pvqspinlock, x86: Allow unfair spinlock in a PV guest
Date: Tue, 18 Mar 2014 09:14:45 +0100 [thread overview]
Message-ID: <53280075.1020804@redhat.com> (raw)
In-Reply-To: <20140317190511.GB11707@phenom.dumpdata.com>
Il 17/03/2014 20:05, Konrad Rzeszutek Wilk ha scritto:
>> > Measurements were done by Gleb for two guests running 2.6.32 with 16
>> > vcpus each, on a 16-core system. One guest ran with unfair locks,
>> > one guest ran with fair locks. Two kernel compilations ("time make
> And when you say fair locks are you saying PV ticketlocks or generic
> ticketlocks?
Generic, of course.
> You should see the same values with the PV ticketlock. It is not clear
> to me if this testing did include that variant of locks?
Yes, PV is fine. But up to this point of the series, we are concerned
about spinlock performance when running on an overcommitted hypervisor
that doesn't support PV spinlocks.
Paolo
WARNING: multiple messages have this Message-ID (diff)
From: Paolo Bonzini <pbonzini@redhat.com>
To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>,
Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>,
Gleb Natapov <gleb@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
virtualization@lists.linux-foundation.org,
Andi Kleen <andi@firstfloor.org>,
"H. Peter Anvin" <hpa@zytor.com>,
Michel Lespinasse <walken@google.com>,
Alok Kataria <akataria@vmware.com>,
linux-arch@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org,
Ingo Molnar <mingo@redhat.com>,
xen-devel@lists.xenproject.org,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Rik van Riel <riel@redhat.com>, Arnd Bergmann <arnd@arndb.de>,
Scott J Norton <scott.norton@hp.com>,
Steven Rostedt <rostedt@goodmis.org>,
Chris Wright <chrisw@sous-sol.org>,
Thomas Gleixner <tglx@linutronix.de>,
Aswin Chandramouleeswaran <aswin@hp.com>,
Chegu Vinod <chegu_vinod@hp.com>,
Waiman Long <Waiman.Long@hp.com>, Oleg Nesterov <oleg@redhat.com>
Subject: Re: [PATCH v6 05/11] pvqspinlock, x86: Allow unfair spinlock in a PV guest
Date: Tue, 18 Mar 2014 09:14:45 +0100 [thread overview]
Message-ID: <53280075.1020804@redhat.com> (raw)
Message-ID: <20140318081445.D2JGb2eAhQ8USTeNlTVVSns_eJRBrrmNegvTKpmNdHc@z> (raw)
In-Reply-To: <20140317190511.GB11707@phenom.dumpdata.com>
Il 17/03/2014 20:05, Konrad Rzeszutek Wilk ha scritto:
>> > Measurements were done by Gleb for two guests running 2.6.32 with 16
>> > vcpus each, on a 16-core system. One guest ran with unfair locks,
>> > one guest ran with fair locks. Two kernel compilations ("time make
> And when you say fair locks are you saying PV ticketlocks or generic
> ticketlocks?
Generic, of course.
> You should see the same values with the PV ticketlock. It is not clear
> to me if this testing did include that variant of locks?
Yes, PV is fine. But up to this point of the series, we are concerned
about spinlock performance when running on an overcommitted hypervisor
that doesn't support PV spinlocks.
Paolo
next prev parent reply other threads:[~2014-03-18 8:14 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-12 18:54 [PATCH v6 00/11] qspinlock: a 4-byte queue spinlock with PV support Waiman Long
2014-03-12 18:54 ` [PATCH v6 01/11] qspinlock: A generic 4-byte queue spinlock implementation Waiman Long
2014-03-12 18:54 ` [PATCH v6 02/11] qspinlock, x86: Enable x86-64 to use queue spinlock Waiman Long
2014-03-12 18:54 ` [PATCH v6 03/11] qspinlock: More optimized code for smaller NR_CPUS Waiman Long
2014-03-12 18:54 ` [PATCH v6 04/11] qspinlock: Optimized code path for 2 contending tasks Waiman Long
2014-03-12 19:08 ` Waiman Long
2014-03-13 13:57 ` Peter Zijlstra
2014-03-17 17:23 ` Waiman Long
2014-03-12 18:54 ` [PATCH v6 05/11] pvqspinlock, x86: Allow unfair spinlock in a PV guest Waiman Long
2014-03-13 10:54 ` David Vrabel
2014-03-13 13:16 ` Paolo Bonzini
2014-03-13 13:16 ` Paolo Bonzini
2014-03-17 19:05 ` Konrad Rzeszutek Wilk
2014-03-17 19:05 ` Konrad Rzeszutek Wilk
2014-03-18 8:14 ` Paolo Bonzini [this message]
2014-03-18 8:14 ` Paolo Bonzini
2014-03-19 3:15 ` Waiman Long
2014-03-19 3:15 ` Waiman Long
2014-03-19 10:07 ` Paolo Bonzini
2014-03-19 16:58 ` Waiman Long
2014-03-19 17:08 ` Paolo Bonzini
2014-03-19 17:08 ` Paolo Bonzini
2014-03-13 19:03 ` Waiman Long
2014-03-13 15:15 ` Peter Zijlstra
2014-03-13 20:05 ` Waiman Long
2014-03-14 8:30 ` Peter Zijlstra
2014-03-14 8:48 ` Paolo Bonzini
2014-03-14 8:48 ` Paolo Bonzini
2014-03-17 17:44 ` Waiman Long
2014-03-17 18:54 ` Peter Zijlstra
2014-03-18 8:16 ` Paolo Bonzini
2014-03-18 8:16 ` Paolo Bonzini
2014-03-19 3:08 ` Waiman Long
2014-03-17 19:10 ` Konrad Rzeszutek Wilk
2014-03-19 3:11 ` Waiman Long
2014-03-19 15:25 ` Konrad Rzeszutek Wilk
2014-03-12 18:54 ` [PATCH v6 06/11] pvqspinlock, x86: Allow unfair queue spinlock in a KVM guest Waiman Long
2014-03-12 18:54 ` [PATCH v6 07/11] pvqspinlock, x86: Allow unfair queue spinlock in a XEN guest Waiman Long
2014-03-12 18:54 ` [PATCH v6 08/11] pvqspinlock, x86: Rename paravirt_ticketlocks_enabled Waiman Long
2014-03-12 18:54 ` [PATCH RFC v6 09/11] pvqspinlock, x86: Add qspinlock para-virtualization support Waiman Long
2014-03-13 11:21 ` David Vrabel
2014-03-13 13:57 ` Paolo Bonzini
2014-03-13 13:57 ` Paolo Bonzini
2014-03-13 19:49 ` Waiman Long
2014-03-13 19:49 ` Waiman Long
2014-03-14 9:44 ` Paolo Bonzini
2014-03-14 9:44 ` Paolo Bonzini
2014-03-13 19:05 ` Waiman Long
2014-03-12 18:54 ` [PATCH RFC v6 10/11] pvqspinlock, x86: Enable qspinlock PV support for KVM Waiman Long
2014-03-13 13:59 ` Paolo Bonzini
2014-03-13 13:59 ` Paolo Bonzini
2014-03-13 19:13 ` Waiman Long
2014-03-14 8:42 ` Paolo Bonzini
2014-03-17 17:47 ` Waiman Long
2014-03-17 17:47 ` Waiman Long
2014-03-18 8:18 ` Paolo Bonzini
2014-03-13 15:25 ` Peter Zijlstra
2014-03-13 20:09 ` Waiman Long
2014-03-12 18:54 ` [PATCH RFC v6 11/11] pvqspinlock, x86: Enable qspinlock PV support for XEN Waiman Long
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