From: Andi Kleen <andi@firstfloor.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: the arch/x86 maintainers <x86@kernel.org>,
KVM <kvm@vger.kernel.org>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Peter Zijlstra <peterz@infradead.org>,
Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>,
LKML <linux-kernel@vger.kernel.org>,
Andi Kleen <andi@firstfloor.org>,
Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
Avi Kivity <avi@redhat.com>,
Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Attilio Rao <attilio.rao@citrix.com>, Ingo Molnar <mingo@elte.hu>,
Virtualization <virtualization@lists.linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Xen Devel <xen-devel@lists.xensource.com>,
Stephan Diestelhorst <stephan.diestelhorst@amd.com>
Subject: Re: [PATCH RFC V6 0/11] Paravirtualized ticketlocks
Date: Sat, 31 Mar 2012 00:18:36 +0200 [thread overview]
Message-ID: <20120330221836.GN17822@one.firstfloor.org> (raw)
In-Reply-To: <alpine.LFD.2.02.1203302333560.2542@ionos>
> So if a guest exits due to an external event it's easy to inspect the
> state of that guest and avoid to schedule away when it was interrupted
> in a spinlock held section. That guest/host shared state needs to be
On a large system under high contention sleeping can perform surprisingly
well. pthread mutexes have a tendency to beat kernel spinlocks there.
So avoiding sleeping locks completely (that is what pv locks are
essentially) is not necessarily that good.
Your proposal is probably only a good idea on low contention
and relatively small systems.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2012-03-30 22:18 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-21 10:20 [PATCH RFC V6 0/11] Paravirtualized ticketlocks Raghavendra K T
2012-03-21 10:20 ` [PATCH RFC V6 1/11] x86/spinlock: replace pv spinlocks with pv ticketlocks Raghavendra K T
2012-03-21 13:04 ` Attilio Rao
2012-03-21 13:22 ` Stephan Diestelhorst
2012-03-21 13:49 ` Attilio Rao
2012-03-21 14:25 ` Stephan Diestelhorst
2012-03-21 14:33 ` Attilio Rao
2012-03-21 14:49 ` Raghavendra K T
2012-03-21 10:21 ` [PATCH RFC V6 2/11] x86/ticketlock: don't inline _spin_unlock when using paravirt spinlocks Raghavendra K T
2012-03-21 17:13 ` Linus Torvalds
2012-03-22 10:06 ` Raghavendra K T
2012-03-21 10:21 ` [PATCH RFC V6 3/11] x86/ticketlock: collapse a layer of functions Raghavendra K T
2012-03-21 10:21 ` [PATCH RFC V6 4/11] xen: defer spinlock setup until boot CPU setup Raghavendra K T
2012-03-21 10:21 ` [PATCH RFC V6 5/11] xen/pvticketlock: Xen implementation for PV ticket locks Raghavendra K T
2012-03-21 10:21 ` [PATCH RFC V6 6/11] xen/pvticketlocks: add xen_nopvspin parameter to disable xen pv ticketlocks Raghavendra K T
2012-03-21 10:21 ` [PATCH RFC V6 7/11] x86/pvticketlock: use callee-save for lock_spinning Raghavendra K T
2012-03-21 10:22 ` [PATCH RFC V6 8/11] x86/pvticketlock: when paravirtualizing ticket locks, increment by 2 Raghavendra K T
2012-03-21 10:22 ` [PATCH RFC V6 9/11] x86/ticketlock: add slowpath logic Raghavendra K T
2012-03-21 10:22 ` [PATCH RFC V6 10/11] xen/pvticketlock: allow interrupts to be enabled while blocking Raghavendra K T
2012-03-21 10:22 ` [PATCH RFC V6 11/11] xen: enable PV ticketlocks on HVM Xen Raghavendra K T
2012-03-26 14:25 ` [PATCH RFC V6 0/11] Paravirtualized ticketlocks Avi Kivity
2012-03-27 7:37 ` Raghavendra K T
2012-03-28 16:09 ` Alan Meadows
2012-03-28 18:21 ` Raghavendra K T
2012-03-29 9:58 ` Avi Kivity
2012-03-29 18:03 ` Raghavendra K T
2012-03-30 10:07 ` Raghavendra K T
2012-04-01 13:18 ` Avi Kivity
2012-04-01 13:48 ` Raghavendra K T
2012-04-01 13:53 ` Avi Kivity
2012-04-01 13:56 ` Raghavendra K T
2012-04-02 9:51 ` Raghavendra K T
2012-04-02 12:15 ` Raghavendra K T
2012-04-05 9:01 ` Avi Kivity
2012-04-05 10:40 ` Raghavendra K T
2012-04-05 8:43 ` Raghavendra K T
2012-03-30 20:26 ` H. Peter Anvin
2012-03-30 22:07 ` Thomas Gleixner
2012-03-30 22:18 ` Andi Kleen [this message]
2012-03-30 23:04 ` Thomas Gleixner
2012-03-31 0:08 ` Andi Kleen
2012-03-31 8:11 ` Ingo Molnar
2012-03-31 4:07 ` Srivatsa Vaddagiri
2012-03-31 4:09 ` Srivatsa Vaddagiri
2012-04-16 15:44 ` Konrad Rzeszutek Wilk
2012-04-16 16:36 ` [Xen-devel] " Ian Campbell
2012-04-16 16:42 ` Jeremy Fitzhardinge
2012-04-17 2:54 ` Srivatsa Vaddagiri
2012-04-01 13:31 ` Avi Kivity
2012-04-02 9:26 ` Thomas Gleixner
2012-04-05 9:15 ` Avi Kivity
2012-04-02 4:36 ` [Xen-devel] " Juergen Gross
2012-04-02 9:42 ` Ian Campbell
2012-04-11 1:29 ` Marcelo Tosatti
2012-03-31 0:51 ` Raghavendra K T
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