lkml.org 
[lkml]   [2018]   [Jan]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 0/2] genirq/affinity: try to make sure online CPU is assgined to irq vector
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




\
 
 \ /
  Last update: 2018-01-16 12:26    [W:0.064 / U:1.352 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site