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From: "H. Peter Anvin" <hpa@zytor.com>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>, Ingo Molnar <mingo@elte.hu>,
	kexec <kexec@lists.infradead.org>,
	caiqian@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: kexec load failure introduced by "x86, memblock: Replace e820_/_early string with memblock_"
Date: Mon, 27 Sep 2010 20:46:42 -0700	[thread overview]
Message-ID: <4CA16522.8060107@zytor.com> (raw)
In-Reply-To: <20100928005358.GA6456@redhat.com>

On 09/27/2010 05:53 PM, Vivek Goyal wrote:
> 
> Actually, hardcoding the upper limit to 4G is probably not the best idea.
> Kexec loads the the relocatable binary (purgatory) and I remember that
> one of the generated relocation type was signed 32 bit and allowed max value
> to be 2G only. So IIRC, purgatory code always needed to be loaded below 2G.
> 
> I liked HPA's other idea better of introducing memblock_find_in_range_lowest() 
> so that we search bottom up and not rely on a specific upper limit.
> 

No, it's just another crappy hack which is broken in the same way.  It's
better than open-coding, but it's still a hack.

The Right Thing[TM] to do is for kexec to communicate the topmost
address it wants to this code, so it has both the upper and the lower
boundaries available to it instead of just one.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.


  parent reply	other threads:[~2010-09-28  3:47 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1909915255.2046011285586388234.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com>
2010-09-27 11:21 ` kexec load failure introduced by "x86, memblock: Replace e820_/_early string with memblock_" caiqian
2010-09-27 22:22   ` Yinghai Lu
2010-09-27 22:50     ` H. Peter Anvin
2010-09-27 23:20       ` Yinghai Lu
2010-09-27 23:26         ` H. Peter Anvin
2010-09-27 23:32           ` Yinghai Lu
2010-09-27 23:34             ` H. Peter Anvin
2010-09-27 23:41               ` Yinghai Lu
2010-09-28  0:53                 ` Vivek Goyal
2010-09-28  2:41                   ` Yinghai Lu
2010-09-28  3:46                   ` H. Peter Anvin [this message]
2010-09-28  7:14                     ` Yinghai Lu
2010-09-28 14:01                       ` Vivek Goyal
2010-09-28 13:54                     ` Vivek Goyal
     [not found] <870873343.2003871285555329846.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com>
2010-09-27  6:31 ` Yinghai Lu
2010-09-27  9:16   ` CAI Qian

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