From: Thomas Gleixner <tglx@linutronix.de>
To: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>, Jens Axboe <axboe@fb.com>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
Laurence Oberman <loberman@redhat.com>,
Mike Snitzer <snitzer@redhat.com>
Subject: Re: [PATCH 0/2] genirq/affinity: try to make sure online CPU is assgined to irq vector
Date: Tue, 16 Jan 2018 12:25:19 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.20.1801161223500.1823@nanos> (raw)
In-Reply-To: <20180116013043.GA3213@ming.t460p>
On Tue, 16 Jan 2018, Ming Lei wrote:
> On Mon, Jan 15, 2018 at 09:40:36AM -0800, Christoph Hellwig wrote:
> > On Tue, Jan 16, 2018 at 12:03:43AM +0800, Ming Lei wrote:
> > > Hi,
> > >
> > > These two patches fixes IO hang issue reported by Laurence.
> > >
> > > 84676c1f21 ("genirq/affinity: assign vectors to all possible CPUs")
> > > may cause one irq vector assigned to all offline CPUs, then this vector
> > > can't handle irq any more.
> >
> > Well, that very much was the intention of managed interrupts. Why
> > does the device raise an interrupt for a queue that has no online
> > cpu assigned to it?
>
> It is because of irq_create_affinity_masks().
That still does not answer the question. If the interrupt for a queue is
assigned to an offline CPU, then the queue should not be used and never
raise an interrupt. That's how managed interrupts have been designed.
Thanks,
tglx
next prev parent reply other threads:[~2018-01-16 11:25 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-15 16:03 [PATCH 0/2] genirq/affinity: try to make sure online CPU is assgined to irq vector Ming Lei
2018-01-15 16:03 ` [PATCH 1/2] genirq/affinity: move irq vectors spread into one function Ming Lei
2018-01-15 16:03 ` [PATCH 2/2] genirq/affinity: try best to make sure online CPU is assigned to vector Ming Lei
2018-01-15 17:40 ` [PATCH 0/2] genirq/affinity: try to make sure online CPU is assgined to irq vector Christoph Hellwig
2018-01-16 1:30 ` Ming Lei
2018-01-16 11:25 ` Thomas Gleixner [this message]
2018-01-16 12:23 ` Ming Lei
2018-01-16 13:28 ` Laurence Oberman
2018-01-16 15:22 ` Don Brace
2018-01-16 15:35 ` Laurence Oberman
2018-01-16 15:47 ` Ming Lei
2018-02-01 10:36 ` Ming Lei
2018-02-01 14:53 ` Don Brace
2018-02-01 15:04 ` Ming Lei
2018-01-16 2:15 ` Ming Lei
2018-01-15 17:43 ` Thomas Gleixner
2018-01-15 17:54 ` Laurence Oberman
2018-01-16 1:34 ` Ming Lei
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