Message-ID: <4FA8579C.3000205@goop.org>
Date: Mon, 07 May 2012 16:15:40 -0700
From: Jeremy Fitzhardinge <jeremy@goop.org>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120424 Thunderbird/12.0
MIME-Version: 1.0
To: Avi Kivity <avi@redhat.com>
CC: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
        Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>,
        Ingo Molnar <mingo@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Greg Kroah-Hartman <gregkh@suse.de>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Marcelo Tosatti <mtosatti@redhat.com>, X86 <x86@kernel.org>,
        Gleb Natapov <gleb@redhat.com>, Ingo Molnar <mingo@redhat.com>,
        Attilio Rao <attilio.rao@citrix.com>,
        Virtualization <virtualization@lists.linux-foundation.org>,
        Xen Devel <xen-devel@lists.xensource.com>, linux-doc@vger.kernel.org,
        KVM <kvm@vger.kernel.org>, Andi Kleen <andi@firstfloor.org>,
        Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
        Stephan Diestelhorst <stephan.diestelhorst@amd.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH RFC V8 0/17] Paravirtualized ticket spinlocks
References: <20120502100610.13206.40.sendpatchset@codeblue.in.ibm.com> <20120507082928.GI16608@gmail.com> <4FA7888F.80505@redhat.com> <4FA7AAD8.6050003@linux.vnet.ibm.com> <4FA7BABA.4040700@redhat.com> <4FA7CC05.50808@linux.vnet.ibm.com> <4FA7CCA2.4030408@redhat.com> <4FA7D06B.60005@linux.vnet.ibm.com> <20120507134611.GB5533@linux.vnet.ibm.com> <4FA7D2E5.1020607@redhat.com>
In-Reply-To: <4FA7D2E5.1020607@redhat.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 936
Lines: 20

On 05/07/2012 06:49 AM, Avi Kivity wrote:
> On 05/07/2012 04:46 PM, Srivatsa Vaddagiri wrote:
>> * Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> [2012-05-07 19:08:51]:
>>
>>> I 'll get hold of a PLE mc  and come up with the numbers soon. but I
>>> 'll expect the improvement around 1-3% as it was in last version.
>> Deferring preemption (when vcpu is holding lock) may give us better than 1-3% 
>> results on PLE hardware. Something worth trying IMHO.
> Is the improvement so low, because PLE is interfering with the patch, or
> because PLE already does a good job?

How does PLE help with ticket scheduling on unlock?  I thought it would
just help with the actual spin loops.

    J
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/