Subject: Re: [PATCH 2/8] pseries: phyp dump: reserve-release proof-of-concept

From: Manish Ahuja <[email-masked]>
Date: Mon, 11 Feb 2008 12:29:00 -0600

Sorry,

I think i sent the wrong patch file, it shouldn't have my printk statement in there. Let me re-send 
the correct file and let me test it once more to make sure it does the right thing.

-Manish

Paul Mackerras wrote:
> Manish Ahuja writes:
> 
>> Initial patch for reserving memory in early boot, and freeing it later.
>> If the previous boot had ended with a crash, the reserved memory would contain
>> a copy of the crashed kernel data.
> 
> [snip]
> 
>> +static void __init reserve_crashed_mem(void)
>> +{
>> +	unsigned long base, size;
>> +
>> +	if (phyp_dump_info->phyp_dump_is_active) {
>> +		/* Reserve *everything* above RMR. We'll free this real soon.*/
>> +		base = PHYP_DUMP_RMR_END;
>> +		size = lmb_end_of_DRAM() - base;
>> +
>> +		/* XXX crashed_ram_end is wrong, since it may be beyond
>> +	 	* the memory_limit, it will need to be adjusted. */
>> +		lmb_reserve(base, size);
>> +
>> +		phyp_dump_info->init_reserve_start = base;
>> +		phyp_dump_info->init_reserve_size = size;
>> +	}
>> +	else {
>> +		size = phyp_dump_info->cpu_state_size +
>> +			phyp_dump_info->hpte_region_size +
>> +			PHYP_DUMP_RMR_END;
>> +		base = lmb_end_of_DRAM() - size;
>> +	printk(KERN_ERR "Manish reserve regular kernel space is %ld %ld\n", base, size);
>> +		lmb_reserve(base, size);
> 
> This is still reserving memory even on systems that aren't running on
> pHyp at all.  Please rework this so that no memory is reserved if the
> system doesn't support phyp-assisted dump.
> 
> Paul.