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From: "Raj, Ashok" <ashok.raj-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
To: "joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org"
	<joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
Cc: "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org"
	<iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>,
	"Zhuo,
	Qiuxu" <qiuxu.zhuo-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
	"jroedel-l3A5Bk7waGM@public.gmane.org"
	<jroedel-l3A5Bk7waGM@public.gmane.org>,
	"Luck, Tony" <tony.luck-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Subject: Re: Does a new booting kernel by "kexec -l" need to copy IR table from previous kernel?
Date: Thu, 27 Apr 2017 09:21:12 -0700	[thread overview]
Message-ID: <20170427162111.GA7556@linux.intel.com> (raw)
In-Reply-To: <20170427161238.GD1332-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>

Hi Joerg,

On Thu, Apr 27, 2017 at 06:12:38PM +0200, joro@8bytes.org wrote:
> On Thu, Apr 27, 2017 at 03:34:06PM +0000, Zhuo, Qiuxu wrote:
> > It looks like the printk is misleading and it’s nothing actually
> > failed, but just it isn’t copying if the new kernel is not a kdump
> > kernel.
> 
> Yes, that is true. But the messages are harmless and you are safe to
> ignore them in your usecase. We only care about the kdump case when

Looks like maybe sanitizing the message to make it less disturbing 
should be enough :-) 

> copying the old IR and DMAR tables into the new kernel, because in the
> kdump case the old kernel crashed and left devices in an undefined
> state, so that they might still send DMA and IRQ requests to the new
> kernel, corrupting data or causing spurious/blocked irqs. Blocked IRQs
> or DMA requests might even break devices so that the new kernel can't
> initialize them anymore.

Cheers,
Ashok
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  parent reply	other threads:[~2017-04-27 16:21 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-27 15:34 Does a new booting kernel by "kexec -l" need to copy IR table from previous kernel? Zhuo, Qiuxu
     [not found] ` <E6AF1AFDEA62A94A97508F458CBDD47F6EBEFCC9-0J0gbvR4kThpB2pF5aRoyrfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2017-04-27 16:12   ` joro-zLv9SwRftAIdnm+yROfE0A
     [not found]     ` <20170427161238.GD1332-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
2017-04-27 16:21       ` Raj, Ashok [this message]
2017-04-28  8:17       ` Zhuo, Qiuxu

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