From: David Rientjes <rientjes@google.com>
The logic in e820_find_active_regions() for determining the true active
regions for an e820 entry given a range of PFN's is needed for
e820_hole_size() as well.
e820_hole_size() is called from the NUMA emulation code to determine the
reserved area within an address range on a per-node basis. Its logic should
duplicate that of finding active regions in an e820 entry because these are
the only true ranges we may register anyway.
[akpm@linux-foundation.org: cleanup]
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
arch/x86_64/kernel/e820.c | 82 ++++++++++++++++++++++++++--------------------
1 file changed, 48 insertions(+), 34 deletions(-)
Index: linux/arch/x86_64/kernel/e820.c
===================================================================
--- linux.orig/arch/x86_64/kernel/e820.c
+++ linux/arch/x86_64/kernel/e820.c
@@ -289,47 +289,61 @@ void __init e820_mark_nosave_regions(voi
}
}
+/*
+ * Finds an active region in the address range from start_pfn to end_pfn and
+ * returns its range in ei_startpfn and ei_endpfn for the e820 entry.
+ */
+static int __init e820_find_active_region(const struct e820entry *ei,
+ unsigned long start_pfn,
+ unsigned long end_pfn,
+ unsigned long *ei_startpfn,
+ unsigned long *ei_endpfn)
+{
+ *ei_startpfn = round_up(ei->addr, PAGE_SIZE) >> PAGE_SHIFT;
+ *ei_endpfn = round_down(ei->addr + ei->size, PAGE_SIZE) >> PAGE_SHIFT;
+
+ /* Skip map entries smaller than a page */
+ if (*ei_startpfn >= *ei_endpfn)
+ return 0;
+
+ /* Check if end_pfn_map should be updated */
+ if (ei->type != E820_RAM && *ei_endpfn > end_pfn_map)
+ end_pfn_map = *ei_endpfn;
+
+ /* Skip if map is outside the node */
+ if (ei->type != E820_RAM || *ei_endpfn <= start_pfn ||
+ *ei_startpfn >= end_pfn)
+ return 0;
+
+ /* Check for overlaps */
+ if (*ei_startpfn < start_pfn)
+ *ei_startpfn = start_pfn;
+ if (*ei_endpfn > end_pfn)
+ *ei_endpfn = end_pfn;
+
+ /* Obey end_user_pfn to save on memmap */
+ if (*ei_startpfn >= end_user_pfn)
+ return 0;
+ if (*ei_endpfn > end_user_pfn)
+ *ei_endpfn = end_user_pfn;
+
+ return 1;
+}
+
/* Walk the e820 map and register active regions within a node */
void __init
e820_register_active_regions(int nid, unsigned long start_pfn,
unsigned long end_pfn)
{
+ unsigned long ei_startpfn;
+ unsigned long ei_endpfn;
int i;
- unsigned long ei_startpfn, ei_endpfn;
- for (i = 0; i < e820.nr_map; i++) {
- struct e820entry *ei = &e820.map[i];
- ei_startpfn = round_up(ei->addr, PAGE_SIZE) >> PAGE_SHIFT;
- ei_endpfn = round_down(ei->addr + ei->size, PAGE_SIZE)
- >> PAGE_SHIFT;
-
- /* Skip map entries smaller than a page */
- if (ei_startpfn >= ei_endpfn)
- continue;
-
- /* Check if end_pfn_map should be updated */
- if (ei->type != E820_RAM && ei_endpfn > end_pfn_map)
- end_pfn_map = ei_endpfn;
-
- /* Skip if map is outside the node */
- if (ei->type != E820_RAM ||
- ei_endpfn <= start_pfn ||
- ei_startpfn >= end_pfn)
- continue;
-
- /* Check for overlaps */
- if (ei_startpfn < start_pfn)
- ei_startpfn = start_pfn;
- if (ei_endpfn > end_pfn)
- ei_endpfn = end_pfn;
-
- /* Obey end_user_pfn to save on memmap */
- if (ei_startpfn >= end_user_pfn)
- continue;
- if (ei_endpfn > end_user_pfn)
- ei_endpfn = end_user_pfn;
- add_active_range(nid, ei_startpfn, ei_endpfn);
- }
+ for (i = 0; i < e820.nr_map; i++)
+ if (e820_find_active_region(&e820.map[i],
+ start_pfn, end_pfn,
+ &ei_startpfn, &ei_endpfn))
+ add_active_range(nid, ei_startpfn, ei_endpfn);
}
/*
-
