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Date:   Tue, 23 Oct 2018 10:51:27 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Yi Sun <yi.y.sun@linux.intel.com>
Cc:     Waiman Long <longman@redhat.com>, Juergen Gross <jgross@suse.com>,
        linux-kernel@vger.kernel.org, x86@kernel.org, tglx@linutronix.de,
        chao.p.peng@intel.com, chao.gao@intel.com,
        isaku.yamahata@intel.com, michael.h.kelley@microsoft.com,
        tianyu.lan@microsoft.com, "K. Y. Srinivasan" <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Stephen Hemminger <sthemmin@microsoft.com>,
        "mingo@redhat.com" <mingo@redhat.com>,
        Will Deacon <will.deacon@arm.com>
Subject: Re: [PATCH v1 2/2] x86/hyperv: make HvNotifyLongSpinWait hypercall
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On Tue, Oct 23, 2018 at 10:57:40AM +0800, Yi Sun wrote:
> On 18-10-22 19:15:16, Peter Zijlstra wrote:

> > > >>>> +#if defined(CONFIG_X86_64) && defined(CONFIG_PARAVIRT_SPINLOCKS) && IS_ENABLED(CONFIG_HYPERV)
> > > >>>> +			if (!hv_notify_long_spin_wait(SPIN_THRESHOLD - loop))
> > > >>>> +				break;
> > > >>>> +#endif
> > 
> > Secondly; how come you thought that was acceptable in any way shape or
> > form?
> > 
> Sorry for that. Will try another way.

Can you try and explain why vcpu_is_preempted() doesn't work for you?