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| author | David S. Miller <davem@sunset.davemloft.net> | 2007-03-16 06:52:18 +0100 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-04-26 10:55:36 +0200 |
| commit | f1cfdb55f16596752e8a61a8570a90ee26af183a (patch) | |
| tree | 7e081e5d05537cb46b6a145870b00d87f1044ea9 /arch/sparc64 | |
| parent | [SPARC64]: Make sure pbm->prom_node is setup easly enough in psycho.c (diff) | |
| download | linux-f1cfdb55f16596752e8a61a8570a90ee26af183a.tar.xz linux-f1cfdb55f16596752e8a61a8570a90ee26af183a.zip | |
[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>
Diffstat (limited to 'arch/sparc64')
| -rw-r--r-- | arch/sparc64/mm/init.c | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c index 40276189c107..cafadcbcdf38 100644 --- a/arch/sparc64/mm/init.c +++ b/arch/sparc64/mm/init.c @@ -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; /* |