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@xxxxxxxxxx] >>> Sent: Thursday, January 02, 2014 7:14 PM >>> To: Gioh Kim >>> Cc: Russell King; linux-mm@xxxxxxxxx; 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. > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>