From: wujianguo@huawei•com (Jianguo Wu)
To: linux-arm-kernel@lists•infradead.org
Subject: ARM: mm: Could I change module space size or place modules in vmalloc area?
Date: Sat, 26 Apr 2014 10:12:40 +0800 [thread overview]
Message-ID: <535B1618.5030504@huawei.com> (raw)
In-Reply-To: <20140103004716.GG7383@n2100.arm.linux.org.uk>
On 2014/1/3 8:47, Russell King - ARM Linux wrote:
> On Fri, Jan 03, 2014 at 09:39:31AM +0900, Gioh Kim wrote:
>> Thank you for reply.
>>
>>> -----Original Message-----
>>> From: Baruch Siach [mailto:baruch at tkos.co.il]
>>> Sent: Thursday, January 02, 2014 7:14 PM
>>> To: Gioh Kim
>>> Cc: Russell King; linux-mm at kvack.org; linux-arm-kernel; HyoJun Im
>>> Subject: Re: ARM: mm: Could I change module space size or place modules in
>>> vmalloc area?
>>>
>>> Hi Gioh,
>>>
>>> On Thu, Jan 02, 2014 at 07:04:13PM +0900, Gioh Kim wrote:
>>>> I run out of module space because I have several big driver modules.
>>>> I know I can strip the modules to decrease size but I need debug info
>>> now.
>>>
>>> Are you sure you need the debug info in kernel memory? I don't think the
>>> kernel is actually able to parse DWARF. You can load stripped binaries
>>> into the kernel, and still use the debug info with whatever tool you have.
>>
>> I agree you but driver developers of another team don't agree.
>> I don't know why but they say they will strip drivers later :-(
>> So I need to increase modules space size.
>
> ARM can only branch relatively within +/- 32MB. Hence, with a module
> space of 16MB, modules can reach up to a maximum 16MB into the direct-
> mapped kernel image. As module space increases in size, so that figure
> decreases. So, if module space were to be 40MB, the maximum size of the
> kernel binary would be 8MB.
>
Hi Russell ,Arnd or Will,
I encountered the same situation in arm64, I loaded 80+ modules in arm64, and
run out of module address space(64M). Why the module space is restricted to 64M,
can it be expanded?
In commit 257cb2519(arm64: Loadable modules), it mentioned that " Loadable modules
are loaded 64MB below the kernel image due to branch relocation restrictions",
"branch relocation restrictions" is a AArch64 instruction set restrictions?
Thanks,
Jianguo Wu.
> You want to look at a line similar to this:
>
> .text : 0xc0008000 - 0xc031eda0 (3164 kB)
>
> Also, note this:
>
> modules : 0xbf000000 - 0xc0000000 ( 16 MB)
>
> If the difference between the lowest module address (0xbf000000) and the
> highest of .text is greater than 32MB, it's impossible to load modules -
> they will fail to link.
>
> What is the size of your kernel text? (show us the line(s) like the above.)
>
> Thanks.
>
next prev parent reply other threads:[~2014-04-26 2:12 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-02 10:04 ARM: mm: Could I change module space size or place modules in vmalloc area? Gioh Kim
2014-01-02 10:13 ` Baruch Siach
2014-01-03 0:39 ` Gioh Kim
2014-01-03 0:47 ` Russell King - ARM Linux
2014-01-03 2:52 ` Gioh Kim
2014-04-26 2:12 ` Jianguo Wu [this message]
2014-04-29 11:19 ` Will Deacon
2014-04-29 11:35 ` Arnd Bergmann
2014-04-29 12:40 ` Will Deacon
2014-01-03 12:10 ` Arnd Bergmann
2014-01-03 12:22 ` Russell King - ARM Linux
2014-01-03 13:23 ` Arnd Bergmann
2014-03-12 6:38 ` Gioh Kim
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=535B1618.5030504@huawei.com \
--to=wujianguo@huawei$(echo .)com \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox