From: Randy Dunlap <rdunlap@infradead.org>
To: Andiry Xu <andiry@gmail.com>, linux-kernel@vger.kernel.org
Cc: Andiry Xu <andiry.xu@gmail.com>, Linux MM <linux-mm@kvack.org>
Subject: Re: [BUG] Description for memmap in kernel-parameters.txt is wrong
Date: Thu, 30 Jan 2014 11:25:08 -0800 [thread overview]
Message-ID: <52EAA714.3080809@infradead.org> (raw)
In-Reply-To: <CAOvWMLa334E8CYJLrHy6-0ZXBRneoMf-05v422SQw+dbGRubow@mail.gmail.com>
[adding linux-mm mailing list]
On 01/30/2014 08:52 AM, Andiry Xu wrote:
> Hi,
>
> In kernel-parameters.txt, there is following description:
>
> memmap=nn[KMG]$ss[KMG]
> [KNL,ACPI] Mark specific memory as reserved.
> Region of memory to be used, from ss to ss+nn.
Should be:
Region of memory to be reserved, from ss to ss+nn.
but that doesn't help with the problem that you describe, does it?
> Unfortunately this is incorrect. The meaning of nn and ss is reversed.
> For example:
>
> Command Expected Result
> memmap 2G$6G 6G - 8G reserved 2G - 8G reserved
> memmap 6G$2G 2G - 8G reserved 6G - 8G reserved
Are you testing on x86?
The code in arch/x86/kernel/e820.c always parses mem_size followed by start address.
I don't (yet) see where it goes wrong...
> Test kernel version 3.13, but I believe the issue has been there long ago.
>
> I'm not sure whether the description or implementation should be
> fixed, but apparently they do not match.
I prefer to change the documentation and leave the implementation as is.
--
~Randy
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WARNING: multiple messages have this Message-ID (diff)
From: Randy Dunlap <rdunlap@infradead.org>
To: Andiry Xu <andiry@gmail.com>, linux-kernel@vger.kernel.org
Cc: Andiry Xu <andiry.xu@gmail.com>, Linux MM <linux-mm@kvack.org>
Subject: Re: [BUG] Description for memmap in kernel-parameters.txt is wrong
Date: Thu, 30 Jan 2014 11:25:08 -0800 [thread overview]
Message-ID: <52EAA714.3080809@infradead.org> (raw)
In-Reply-To: <CAOvWMLa334E8CYJLrHy6-0ZXBRneoMf-05v422SQw+dbGRubow@mail.gmail.com>
[adding linux-mm mailing list]
On 01/30/2014 08:52 AM, Andiry Xu wrote:
> Hi,
>
> In kernel-parameters.txt, there is following description:
>
> memmap=nn[KMG]$ss[KMG]
> [KNL,ACPI] Mark specific memory as reserved.
> Region of memory to be used, from ss to ss+nn.
Should be:
Region of memory to be reserved, from ss to ss+nn.
but that doesn't help with the problem that you describe, does it?
> Unfortunately this is incorrect. The meaning of nn and ss is reversed.
> For example:
>
> Command Expected Result
> memmap 2G$6G 6G - 8G reserved 2G - 8G reserved
> memmap 6G$2G 2G - 8G reserved 6G - 8G reserved
Are you testing on x86?
The code in arch/x86/kernel/e820.c always parses mem_size followed by start address.
I don't (yet) see where it goes wrong...
> Test kernel version 3.13, but I believe the issue has been there long ago.
>
> I'm not sure whether the description or implementation should be
> fixed, but apparently they do not match.
I prefer to change the documentation and leave the implementation as is.
--
~Randy
next prev parent reply other threads:[~2014-01-30 19:25 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-30 16:52 [BUG] Description for memmap in kernel-parameters.txt is wrong Andiry Xu
2014-01-30 19:25 ` Randy Dunlap [this message]
2014-01-30 19:25 ` Randy Dunlap
2014-01-30 19:33 ` Andiry Xu
2014-01-30 19:33 ` Andiry Xu
2014-01-30 20:26 ` Randy Dunlap
2014-01-30 20:26 ` Randy Dunlap
2014-01-30 22:17 ` David Rientjes
2014-01-30 22:17 ` David Rientjes
2014-01-30 22:54 ` Randy Dunlap
2014-01-30 22:54 ` Randy Dunlap
2014-01-30 23:43 ` Andiry Xu
2014-01-30 23:43 ` Andiry Xu
2014-01-30 23:49 ` Randy Dunlap
2014-01-30 23:49 ` Randy Dunlap
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