Re: [PATCH] x86: make sure wakeup code is below 1M -v2

[Yinghai Lu <yinghai@kernel.org>]

Pavel Machek wrote:
> On Tue 2009-11-10 18:27:23, Yinghai Lu wrote:
>> try to find_e820_area/reserve_early, and call acpi_reserve_memory early
>>
>> to get area is below 1M
> 
>> -	acpi_realmode = (unsigned long)alloc_bootmem_low(WAKEUP_SIZE);
>> +	mem = find_e820_area(0, 1<<20, WAKEUP_SIZE, PAGE_SIZE);
>>  
>> -	if (!acpi_realmode) {
>> +	if (mem == -1L) {
>>  		printk(KERN_ERR "ACPI: Cannot allocate lowmem, S3 disabled.\n");
>>  		return;
>>  	}
> 
> How is it better then old code?

could get range below 1M.

alloc_bootmem_low can not make sure get that below 1M.

init_memory_mapping could use below 1M as page table...

so need to get some buffer for acpi wakeup realmode code.

YH