Subject: Re: [PATCH v5, part4 31/41] mm/ppc: prepare for removing num_physpages and simplify mem_init()

From: Liu Jiang <[email-masked]>
Date: Wed, 15 May 2013 23:49:42 +0800

On Wed 15 May 2013 08:32:34 AM CST, Benjamin Herrenschmidt wrote:
> On Wed, 2013-05-08 at 23:51 +0800, Jiang Liu wrote:
>> Prepare for removing num_physpages and simplify mem_init().
>
> No objection, I haven't had a chance to actually build/boot test though.
>
> BTW. A recommended way of doing so which is pretty easy even if you
> don't have access to powerpc hardware nowadays is to use
> qemu-system-ppc64 with -M pseries.
>
> You can find cross compilers for the kernel on kernel.org and you can
> feed qemu with some distro installer ISO.
Hi Benjamin,'
      Thanks for review! As could I assume an "Acked-by"?
      I have installed all cross-compiler from ftp.kernel.org and done 
basic
building tests for these patches. But I haven't run new kernel with qemu
yet, that's a really good suggestion, will try it next time.
Regards!
Gerry

>
> Cheers,
> Ben.
>
>> Signed-off-by: Jiang Liu <[email-masked]>
>> Cc: Benjamin Herrenschmidt <[email-masked]>
>> Cc: Paul Mackerras <[email-masked]>
>> Cc: [email-masked]
>> Cc: [email-masked]
>> ---
>>   arch/powerpc/mm/mem.c |   56 +++++++++++--------------------------------------
>>   1 file changed, 12 insertions(+), 44 deletions(-)
>>
>> diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
>> index b890245..4e24f1c 100644
>> --- a/arch/powerpc/mm/mem.c
>> +++ b/arch/powerpc/mm/mem.c
>> @@ -299,46 +299,27 @@ void __init paging_init(void)
>>
>>   void __init mem_init(void)
>>   {
>> -#ifdef CONFIG_NEED_MULTIPLE_NODES
>> -	int nid;
>> -#endif
>> -	pg_data_t *pgdat;
>> -	unsigned long i;
>> -	struct page *page;
>> -	unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
>> -
>>   #ifdef CONFIG_SWIOTLB
>>   	swiotlb_init(0);
>>   #endif
>>
>> -	num_physpages = memblock_phys_mem_size() >> PAGE_SHIFT;
>>   	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
>>
>>   #ifdef CONFIG_NEED_MULTIPLE_NODES
>> -        for_each_online_node(nid) {
>> -		if (NODE_DATA(nid)->node_spanned_pages != 0) {
>> -			printk("freeing bootmem node %d\n", nid);
>> -			free_all_bootmem_node(NODE_DATA(nid));
>> -		}
>> +	{
>> +		pg_data_t *pgdat;
>> +
>> +		for_each_online_pgdat(pgdat)
>> +			if (pgdat->node_spanned_pages != 0) {
>> +				printk("freeing bootmem node %d\n",
>> +					pgdat->node_id);
>> +				free_all_bootmem_node(pgdat);
>> +			}
>>   	}
>>   #else
>>   	max_mapnr = max_pfn;
>>   	free_all_bootmem();
>>   #endif
>> -	for_each_online_pgdat(pgdat) {
>> -		for (i = 0; i < pgdat->node_spanned_pages; i++) {
>> -			if (!pfn_valid(pgdat->node_start_pfn + i))
>> -				continue;
>> -			page = pgdat_page_nr(pgdat, i);
>> -			if (PageReserved(page))
>> -				reservedpages++;
>> -		}
>> -	}
>> -
>> -	codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
>> -	datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
>> -	initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
>> -	bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
>>
>>   #ifdef CONFIG_HIGHMEM
>>   	{
>> @@ -348,13 +329,9 @@ void __init mem_init(void)
>>   		for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
>>   			phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
>>   			struct page *page = pfn_to_page(pfn);
>> -			if (memblock_is_reserved(paddr))
>> -				continue;
>> -			free_highmem_page(page);
>> -			reservedpages--;
>> +			if (!memblock_is_reserved(paddr))
>> +				free_highmem_page(page);
>>   		}
>> -		printk(KERN_DEBUG "High memory: %luk\n",
>> -		       totalhigh_pages << (PAGE_SHIFT-10));
>>   	}
>>   #endif /* CONFIG_HIGHMEM */
>>
>> @@ -367,16 +344,7 @@ void __init mem_init(void)
>>   		(mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
>>   #endif
>>
>> -	printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
>> -	       "%luk reserved, %luk data, %luk bss, %luk init)\n",
>> -		nr_free_pages() << (PAGE_SHIFT-10),
>> -		num_physpages << (PAGE_SHIFT-10),
>> -		codesize >> 10,
>> -		reservedpages << (PAGE_SHIFT-10),
>> -		datasize >> 10,
>> -		bsssize >> 10,
>> -		initsize >> 10);
>> -
>> +	mem_init_print_info(NULL);
>>   #ifdef CONFIG_PPC32
>>   	pr_info("Kernel virtual memory layout:\n");
>>   	pr_info("  * 0x%08lx..0x%08lx  : fixmap\n", FIXADDR_START, FIXADDR_TOP);
>
>