[PATCH] mm: use symbolic names instead of indices for zone initialisation
Arch-independent zone-sizing is using indices instead of symbolic names to
offset within an array related to zones (max_zone_pfns). The unintended
impact is that ZONE_DMA and ZONE_NORMAL is initialised on powerpc instead
of ZONE_DMA and ZONE_HIGHMEM when CONFIG_HIGHMEM is set. As a result, the
the machine fails to boot but will boot with CONFIG_HIGHMEM turned off.
The following patch properly initialises the max_zone_pfns[] array and uses
symbolic names instead of indices in each architecture using
arch-independent zone-sizing. Two users have successfully booted their
powerpcs with it (one an ibook G4). It has also been boot tested on x86,
x86_64, ppc64 and ia64. Please merge for 2.6.19-rc2.
Credit to Benjamin Herrenschmidt for identifying the bug and rolling the
first fix. Additional credit to Johannes Berg and Andreas Schwab for
reporting the problem and testing on powerpc.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/mm/discontig.c b/arch/i386/mm/discontig.c
index 455597d..ddbdb03 100644
--- a/arch/i386/mm/discontig.c
+++ b/arch/i386/mm/discontig.c
@@ -356,11 +356,12 @@
void __init zone_sizes_init(void)
{
int nid;
- unsigned long max_zone_pfns[MAX_NR_ZONES] = {
- virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT,
- max_low_pfn,
- highend_pfn
- };
+ unsigned long max_zone_pfns[MAX_NR_ZONES];
+ memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
+ max_zone_pfns[ZONE_DMA] =
+ virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
+ max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
+ max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
/* If SRAT has not registered memory, register it now */
if (find_max_pfn_with_active_regions() == 0) {