Date: Thu, 3 Dec 2015 14:43:09 -0800
From: Yunhong Jiang <yunhong.jiang@linux.intel.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: okuno.kohji@jp.panasonic.com, linux-kernel@vger.kernel.org
Subject: Re: Can we conditionally force threading irq with primary and thread
 handler?
Message-ID: <20151203224309.GB19650@jnakajim-build>
References: <20151203191125.GA8945@jnakajim-build>
 <alpine.DEB.2.11.1512032324410.4201@nanos>
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On Thu, Dec 03, 2015 at 11:33:14PM +0100, Thomas Gleixner wrote:
> Yunhong,
> 
> On Thu, 3 Dec 2015, Yunhong Jiang wrote:
> 
> > Hi, Thomas
> > 	On Commit 2a1d3ab8986d1b2 ("genirq: Handle force threading of irqs 
> > with primary and thread handler"), even if the caller of 
> > request_threaded_irq() provides a primary handler, that primary handler will 
> > be invoked in thread context. This may cause some latency issue for high 
> > real time requirement.
> > 
> > 	I checked the discussion on https://lkml.org/lkml/2015/9/19/372 with 
> > Okuno and seems we need this change only if the irq is shared, otherwise, we 
> > can still use Okuno's mechanism, am I right? Do you think it's ok to force 
> > the primary handler for shared IRQ, otherwise, clear the IRQF_ONESHOT?
> 
> If you want to avoid that the primary handler is force threaded, then
> you can indicate that with IRQF_NO_THREAD.

Thaks for reply.
Sure, will do that way. Just feel a bit weird with a valid thread_fn and a 
IRQF_NO_THREAD flags.

Thanks
--jyh
> 
> Thanks,
> 
> 	tglx
> 
> 
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