[SPARC64]: Document and fix calculation of pages_avail.

It should be set to the total number of pages that the
system will really have available after things like
initmem, the bootmem map, and initrd are freed up.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2007-03-15 22:52:18 -07:00
parent 0f3e25049e
commit f1cfdb55f1

View File

@ -938,6 +938,20 @@ static void __init trim_pavail(unsigned long *cur_size_p,
}
}
/* About pages_avail, this is the value we will use to calculate
* the zholes_size[] argument given to free_area_init_node(). The
* page allocator uses this to calculate nr_kernel_pages,
* nr_all_pages and zone->present_pages. On NUMA it is used
* to calculate zone->min_unmapped_pages and zone->min_slab_pages.
*
* So this number should really be set to what the page allocator
* actually ends up with. This means:
* 1) It should include bootmem map pages, we'll release those.
* 2) It should not include the kernel image, except for the
* __init sections which we will also release.
* 3) It should include the initrd image, since we'll release
* that too.
*/
static unsigned long __init bootmem_init(unsigned long *pages_avail,
unsigned long phys_base)
{
@ -1024,7 +1038,6 @@ static unsigned long __init bootmem_init(unsigned long *pages_avail,
initrd_start, initrd_end);
#endif
reserve_bootmem(initrd_start, size);
*pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;
initrd_start += PAGE_OFFSET;
initrd_end += PAGE_OFFSET;
@ -1037,6 +1050,11 @@ static unsigned long __init bootmem_init(unsigned long *pages_avail,
reserve_bootmem(kern_base, kern_size);
*pages_avail -= PAGE_ALIGN(kern_size) >> PAGE_SHIFT;
/* Add back in the initmem pages. */
size = ((unsigned long)(__init_end) & PAGE_MASK) -
PAGE_ALIGN((unsigned long)__init_begin);
*pages_avail += size >> PAGE_SHIFT;
/* Reserve the bootmem map. We do not account for it
* in pages_avail because we will release that memory
* in free_all_bootmem.
@ -1047,7 +1065,6 @@ static unsigned long __init bootmem_init(unsigned long *pages_avail,
(bootmap_pfn << PAGE_SHIFT), size);
#endif
reserve_bootmem((bootmap_pfn << PAGE_SHIFT), size);
*pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;
for (i = 0; i < pavail_ents; i++) {
unsigned long start_pfn, end_pfn;
@ -1539,6 +1556,10 @@ void __init mem_init(void)
#ifdef CONFIG_DEBUG_BOOTMEM
prom_printf("mem_init: Calling free_all_bootmem().\n");
#endif
/* We subtract one to account for the mem_map_zero page
* allocated below.
*/
totalram_pages = num_physpages = free_all_bootmem() - 1;
/*