From: Yinghai Lu <yinghai@kernel.org>
To: Matt Fleming <matt.fleming@intel.com>
Cc: "H. Peter Anvin" <hpa@kernel.org>,
mingo@redhat.com, mjg@redhat.com, linux-kernel@vger.kernel.org,
keithp@keithp.com, rui.zhang@intel.com,
huang.ying.caritas@gmail.com, stable@vger.kernel.org,
tglx@linutronix.de, linux-tip-commits@vger.kernel.org
Subject: Re: [tip:x86/urgent] x86, efi: Delete efi_ioremap() and fix CONFIG_X86_32 oops
Date: Thu, 8 Mar 2012 10:59:05 -0800 [thread overview]
Message-ID: <CAE9FiQVZVNARgs0rzgRpRdbSPydCXoeDat=4DLMNFcyBQuqwng@mail.gmail.com> (raw)
In-Reply-To: <1331206127.3539.69.camel@mfleming-mobl1.ger.corp.intel.com>
On Thu, Mar 8, 2012 at 3:28 AM, Matt Fleming <matt.fleming@intel.com> wrote:
> On Wed, 2012-03-07 at 10:05 -0800, Yinghai Lu wrote:
>> > -
>> > - max_low_pfn_mapped = init_memory_mapping(0, end_pfn << PAGE_SHIFT);
>> > - max_pfn_mapped = max_low_pfn_mapped;
>> > + /* max_low_pfn_mapped is updated here */
>> > + max_pfn_mapped = init_memory_mapping();
>> >
>> > #ifdef CONFIG_X86_64
>> > if (max_pfn > max_low_pfn) {
>> > - max_pfn_mapped = init_memory_mapping(1UL<<32,
>> > - max_pfn<<PAGE_SHIFT);
>> > /* can we preseve max_low_pfn ?*/
>> > max_low_pfn = max_pfn;
>> > }
>>
>> you may need to move those three lines before
>> max_pfn_mapped = init_memory_mapping()
>>
>> otherwise for x86_64, memory from [4G, TOMH) will not be directly mapped.
>
> I'm afraid I don't understand what you mean. The changes in my patch
> mean that init_memory_mapping() doesn't work the way it previously did.
> It will map all the regions in the e820 table and presumably the top of
> memory is contained within one of those regions.
>
> Could you clarify what you think the problem is? Unfortunately I don't
> have a test machine with large amounts of RAM so it's entirely possible
> I've made a mistake somewhere.
in your new init_memory_mapping will only map memory below max_low_pfn.
but the max_low_pfn is under 4g.
So it will be ended up with 4G above memory is not mapped.
Yinghai
next prev parent reply other threads:[~2012-03-08 18:59 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-20 13:30 [PATCH] x86, efi: Delete efi_ioremap() and fix CONFIG_X86_32 oops Matt Fleming
2012-02-23 1:16 ` [tip:x86/urgent] " tip-bot for Matt Fleming
2012-02-23 2:20 ` Yinghai Lu
2012-02-23 3:32 ` H. Peter Anvin
2012-02-23 10:36 ` Yinghai Lu
2012-02-24 4:47 ` H. Peter Anvin
2012-02-28 2:27 ` H. Peter Anvin
2012-03-07 10:30 ` Matt Fleming
2012-03-07 18:05 ` Yinghai Lu
2012-03-08 11:28 ` Matt Fleming
2012-03-08 18:59 ` Yinghai Lu [this message]
2012-03-12 12:38 ` Matt Fleming
2012-03-13 5:39 ` Yinghai Lu
2012-03-15 12:40 ` Matt Fleming
2012-03-15 17:54 ` Yinghai Lu
2012-03-16 18:36 ` Matt Fleming
2012-03-16 19:01 ` Yinghai Lu
2012-03-07 18:14 ` Yinghai Lu
2012-03-07 18:18 ` Matthew Garrett
2012-03-08 12:09 ` Matt Fleming
2012-03-04 0:12 ` Keith Packard
2012-03-04 0:27 ` H. Peter Anvin
2012-03-04 1:33 ` Keith Packard
2012-03-05 10:45 ` Ingo Molnar
2012-03-07 18:31 ` Yinghai Lu
2012-03-05 11:48 ` Matt Fleming
2012-02-28 2:33 ` [PATCH] " H. Peter Anvin
2012-02-28 17:35 ` Matt Fleming
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