Linux IOMMU Development
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From: David Woodhouse <dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
To: Alex Williamson
	<alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
	iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH] iommu/vt-d: Ratelimit fault handler
Date: Tue, 15 Mar 2016 19:47:56 +0000	[thread overview]
Message-ID: <1458071276.78634.124.camel@infradead.org> (raw)
In-Reply-To: <20160315163503.2875.49980.stgit-GCcqpEzw8uZBDLzU/O5InQ@public.gmane.org>


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On Tue, 2016-03-15 at 10:35 -0600, Alex Williamson wrote:
> Fault rates can easily overwhelm the console and make the system
> unresponsive.  Ratelimit to allow an opportunity for maintenance.
> 
> Signed-off-by: Alex Williamson <alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>

Rather than just rate-limiting the printk, I'd prefer to handle this
explicitly. There's a bit in the context-entry which can tell the IOMMU
not to bother raising an interrupt at all. And then we can re-enable it
if/when the driver recovers the device. (Or perhaps just when it next
does a mapping).

We really ought to be reporting faults to drivers too, FWIW. I keep
meaning to take a look at that.

-- 
David Woodhouse                            Open Source Technology Centre
David.Woodhouse-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org                              Intel Corporation


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  parent reply	other threads:[~2016-03-15 19:47 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-15 16:35 [PATCH] iommu/vt-d: Ratelimit fault handler Alex Williamson
2016-03-15 17:10 ` Joe Perches
2016-03-15 18:01   ` Joe Perches
     [not found] ` <20160315163503.2875.49980.stgit-GCcqpEzw8uZBDLzU/O5InQ@public.gmane.org>
2016-03-15 19:47   ` David Woodhouse [this message]
     [not found]     ` <1458071276.78634.124.camel-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2016-03-17 16:53       ` Alex Williamson

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