Re: [PATCH] cheat for support of more than 256MB memory

[Tian <tiansm@lemote.com>]

Ralf Baechle wrote:
> On Wed, Jun 06, 2007 at 08:38:18AM +0200, Franck Bui-Huu wrote:
>
>   
>>> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
>>> index 4975da0..62ef100 100644
>>> --- a/arch/mips/kernel/setup.c
>>> +++ b/arch/mips/kernel/setup.c
>>> @@ -509,6 +509,14 @@ static void __init resource_init(void)
>>>                res->end = end;
>>>
>>>                res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
>>> +#if defined(CONFIG_LEMOTE_FULONG) && defined(CONFIG_64BIT)
>>> +               /* to keep memory continous, we tell system 0x10000000 - 
>>> 0x20000000 is reserved
>>> +                * for memory, in fact it is io region, don't occupy it
>>> +                *
>>> +                * SPARSEMEM?
>>>       
>> Definetly yes ! It has been designed for such issue and it should save
>> you some memory.
>>     
>
> A hole of 256MB size in the memory address map will cost 3.5MB with a 64-bit
> kernel.  The other reason why I don't like this patch is that it drags
> platform specific code into the generic MIPS code.
>
>   Ralf
>
>
>   
we use 16k page，so it's cheaper than that:)

Before I work out sparse memory solution, I think I can drop this patch 
and make some trivial fix of the first patch.

Subject: [PATCH] simply ignore the memory hole

Signed-off-by: Songmao Tian <tiansm@lemote.com>
---
 arch/mips/lemote/lm2e/setup.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/arch/mips/lemote/lm2e/setup.c b/arch/mips/lemote/lm2e/setup.c
index 3030518..2498bbf 100644
--- a/arch/mips/lemote/lm2e/setup.c
+++ b/arch/mips/lemote/lm2e/setup.c
@@ -112,7 +112,6 @@ void __init plat_mem_setup(void)
     add_memory_region(0x0, (memsize << 20), BOOT_MEM_RAM);
 #ifdef CONFIG_64BIT
     if (highmemsize > 0) {
-        add_memory_region(0x10000000, 0x10000000, BOOT_MEM_RESERVED);
         add_memory_region(0x20000000, highmemsize << 20, BOOT_MEM_RAM);
     }
 #endif