Subject: Re: [PATCH] pseries: phyp dump: Variable size reserve space.

From: Manish Ahuja <[email-masked]>
Date: Wed, 09 Apr 2008 12:37:51 -0500

Olof Johansson wrote:
>> +static inline unsigned long phyp_dump_calculate_reserve_size(void)
>> +{
>> +	unsigned long tmp;
>> +
>> +	if (phyp_dump_info->phyp_dump_reserve_bootvar)
>> +		return phyp_dump_info->phyp_dump_reserve_bootvar;
>> +
>> +	/* divide by 20 to get 5% of value */
>> +	tmp = lmb_end_of_DRAM();
>> +	do_div(tmp, 20);
>> +
>> +	/* round it down in multiples of 256 */
>> +	tmp = tmp & ~0x000000001FFFFFFF;
> 
> That's 512MB, isn't it?

My calculations in the example I gave in the last email were wrong.

In mentally did 10% instead of 5%. But the premise is same.

So assuming 5% of some memory is 400 MB, it rounds it down to 256MB etc.