From: "H. Peter Anvin" <hpa@zytor.com>
To: Yinghai Lu <yinghai@kernel.org>
Cc: Thomas Renninger <trenn@suse.de>,
x86@kernel.org, linux-kernel@vger.kernel.org,
kexec@lists.infradead.org, vgoyal@redhat.com, horms@verge.net.au
Subject: Re: [PATCH 2/2] x86 e820: Introduce memmap=resetusablemap for kdump usage
Date: Mon, 28 Jan 2013 18:20:55 -0800 [thread overview]
Message-ID: <51073207.7040607@zytor.com> (raw)
In-Reply-To: <CAE9FiQVG4ShGKSdjzYhQaXNNhS=MVNJg=QqG1yW-mAUscErXMA@mail.gmail.com>
On 01/28/2013 06:19 PM, Yinghai Lu wrote:
> On Mon, Jan 28, 2013 at 6:11 PM, H. Peter Anvin <hpa@zytor.com> wrote:
>> On 01/28/2013 06:10 PM, Yinghai Lu wrote:
>>>
>>>
>>> kexec-tools will change that to E820_KDUMP_RESERVED (or other good name).
>>>
>>> We only need to update kernel to get old max_pfn by
>>> checking E820_KDUMP_RESERVED.
>>>
>>
>> OK, I have asked this before, but I still have not gotten any acceptable
>> answer:
>>
>> Why do we still have max_*_pfn at all? Shouldn't it all be based on
>> memblocks by now?
>
> saved_max_pfn is used for kdump:
> drivers/char/mem.c::read_oldmem will stop there.
> ...
> while (count) {
> pfn = *ppos / PAGE_SIZE;
> if (pfn > saved_max_pfn)
> return read;
> ...
That is a non-answer.
Why do we have *any* instances of max_pfn or max_low_pfn in the kernel
anymore?
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
next prev parent reply other threads:[~2013-01-29 2:21 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-22 15:20 [PATCH 0/2] Only parse exactmap once, introduce memmap=resetusablemap Thomas Renninger
2013-01-22 15:20 ` [PATCH 1/2] x86 e820: Check for exactmap appearance when parsing first memmap option Thomas Renninger
2013-01-22 19:33 ` Yinghai Lu
2013-01-29 1:09 ` H. Peter Anvin
2013-01-29 2:01 ` Yinghai Lu
2013-01-22 15:20 ` [PATCH 2/2] x86 e820: Introduce memmap=resetusablemap for kdump usage Thomas Renninger
2013-01-22 15:54 ` H. Peter Anvin
2013-01-22 16:23 ` Thomas Renninger
2013-01-22 16:32 ` H. Peter Anvin
2013-01-22 20:06 ` Yinghai Lu
2013-01-24 4:07 ` Yinghai Lu
2013-01-29 1:05 ` Thomas Renninger
2013-01-29 1:11 ` H. Peter Anvin
2013-01-29 2:10 ` Yinghai Lu
2013-01-29 2:11 ` H. Peter Anvin
2013-01-29 2:19 ` Yinghai Lu
2013-01-29 2:20 ` H. Peter Anvin [this message]
2013-01-29 2:27 ` H. Peter Anvin
2013-01-29 2:31 ` Yinghai Lu
2013-01-29 3:33 ` H. Peter Anvin
2013-01-29 9:47 ` Thomas Renninger
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