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Date:   Wed, 6 Jun 2018 10:04:39 +0200 (CEST)
From:   Thomas Gleixner <tglx@linutronix.de>
To:     Dou Liyang <douly.fnst@cn.fujitsu.com>
cc:     LKML <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Borislav Petkov <bp@alien8.de>,
        Dmitry Safonov <0x7f454c46@gmail.com>,
        Tariq Toukan <tariqt@mellanox.com>,
        Song Liu <liu.song.a23@gmail.com>,
        Joerg Roedel <jroedel@suse.de>,
        Mike Travis <mike.travis@hpe.com>, stable@vger.kernel.org
Subject: Re: [patch 3/8] x86/apic: Provide apic_ack_irq()
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References: <20180604162224.471925894@linutronix.de> <94117bd8-352b-1077-e8ae-8722d7ec213f@cn.fujitsu.com> <alpine.DEB.2.21.1806051339020.1591@nanos.tec.linutronix.de> <de96585f-9b8d-4536-a9d5-32a718e3eb4d@cn.fujitsu.com>
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On Wed, 6 Jun 2018, Dou Liyang wrote:

> Hi Thomas,
> 
> At 06/05/2018 07:41 PM, Thomas Gleixner wrote:
> > On Tue, 5 Jun 2018, Dou Liyang wrote:
> > > > +{
> > > > +	if (unlikely(irqd_is_setaffinity_pending(irqd)))
> > > 
> > > Affinity pending is also judged in
> > > 
> > > > +		irq_move_irq(irqd);
> > > 
> > > If we can remove the if(...) statement here
> > 
> > That requires to fix all call sites in ia64 and that's why I didn't.  But
> 
> I didn't express clearly, I meant remove the if(...) statement from
> apic_ack_irq(), it doesn't require to fix the call sites in ia64.

I put the check there on purpose as I explained in the changelog:

   Making the invocation of irq_move_irq() conditional avoids the out of
   line call if the pending bit is not set.

Thanks,

	tglx