Date: Thu, 11 Jul 2013 13:11:04 +0300
From: Gleb Natapov <gleb@redhat.com>
To: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Andrew Jones <drjones@redhat.com>, mingo@redhat.com, ouyang@cs.pitt.edu,
        habanero@linux.vnet.ibm.com, jeremy@goop.org, x86@kernel.org,
        konrad.wilk@oracle.com, hpa@zytor.com, pbonzini@redhat.com,
        linux-doc@vger.kernel.org, xen-devel@lists.xensource.com,
        peterz@infradead.org, mtosatti@redhat.com,
        stefano.stabellini@eu.citrix.com, andi@firstfloor.org,
        attilio.rao@citrix.com, gregkh@suse.de, agraf@suse.de,
        chegu_vinod@hp.com, torvalds@linux-foundation.org,
        avi.kivity@gmail.com, tglx@linutronix.de, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, riel@redhat.com,
        virtualization@lists.linux-foundation.org,
        srivatsa.vaddagiri@gmail.com
Subject: Re: [PATCH RFC V9 0/19] Paravirtualized ticket spinlocks
Message-ID: <20130711101104.GF8575@redhat.com>
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 <20130710103325.GP24941@redhat.com>
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On Thu, Jul 11, 2013 at 03:40:38PM +0530, Raghavendra K T wrote:
> >>>>Gleb,
> >>>>Can you elaborate little more on what you have in mind regarding per
> >>>>VM ple_window. (maintaining part of it as a per vm variable is clear
> >>>>to
> >>>>  me), but is it that we have to load that every time of guest entry?
> >>>>
> >>>Only when it changes, shouldn't be to often no?
> >>
> >>Ok. Thinking how to do. read the register and writeback if there need
> >>to be a change during guest entry?
> >>
> >Why not do it like in the patch you've linked? When value changes write it
> >to VMCS of the current vcpu.
> >
> 
> Yes. can be done. So the running vcpu's ple_window gets updated only
> after next pl-exit. right?
I am not sure what you mean. You cannot change vcpu's ple_window while
vcpu is in a guest mode.

--
			Gleb.
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