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Date: Thu, 20 Jan 2011 09:49:35 -0800
From: Jeremy Fitzhardinge <jeremy@goop.org>
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CC: Peter Zijlstra <peterz@infradead.org>,
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        Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>,
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Subject: Re: [PATCH 2/3] kvm hypervisor : Add hypercalls to support pv-ticketlock
References: <cover.1289940821.git.jeremy.fitzhardinge@citrix.com> <20110119164432.GA30669@linux.vnet.ibm.com> <20110119171239.GB726@linux.vnet.ibm.com> <1295457672.28776.144.camel@laptop> <4D373340.60608@goop.org> <20110120114246.GA11177@linux.vnet.ibm.com>
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On 01/20/2011 03:42 AM, Srivatsa Vaddagiri wrote:
> On Wed, Jan 19, 2011 at 10:53:52AM -0800, Jeremy Fitzhardinge wrote:
>>> The reason for wanting this should be clear I guess, it allows PI.
>> Well, if we can expand the spinlock to include an owner, then all this
>> becomes moot...
> How so? Having an owner will not eliminate the need for pv-ticketlocks
> afaict. We still need a mechanism to reduce latency in scheduling the next
> thread-in-waiting, which is achieved by your patches. 

No, sorry, I should have been clearer.  I meant that going to the effort
of not increasing the lock size to record "in slowpath" state.

    J