Subject: [PATCH 7/7] Print out debugging information during initialisation

From: Mel Gorman <[email-masked]>
Date: Tue, 18 Apr 2006 14:02:36 +0100 (IST)

The zone and hole sizing code is new and unexpected problems showed up
on machines that were not covered by the pre-release tests. This patch
prints out useful information when those unexpected situations occur.

It is not expected that this patch become a permanent part of the set.

 mem_init.c |   51 +++++++++++++++++++++++++++++++++++++++++++++++----
 1 files changed, 47 insertions(+), 4 deletions(-)

Signed-off-by: Mel Gorman <[email-masked]>
diff -rup -X /usr/src/patchset-0.5/bin//dontdiff linux-2.6.17-rc1-106-breakout_mem_init/mm/mem_init.c linux-2.6.17-rc1-107-debug/mm/mem_init.c
--- linux-2.6.17-rc1-106-breakout_mem_init/mm/mem_init.c	2006-04-18 10:22:00.000000000 +0100
+++ linux-2.6.17-rc1-107-debug/mm/mem_init.c	2006-04-18 10:23:46.000000000 +0100
@@ -593,6 +593,7 @@ static __meminit void init_currently_emp
 }
 
 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
+
 /* Note: nid == MAX_NUMNODES returns first region */
 static int __init first_active_region_index_in_nid(int nid)
 {
@@ -645,13 +646,24 @@ void __init free_bootmem_with_active_reg
 	for_each_active_range_index_in_nid(i, nid) {
 		unsigned long size_pages = 0;
 		unsigned long end_pfn = early_node_map[i].end_pfn;
-		if (early_node_map[i].start_pfn >= max_low_pfn)
+		if (early_node_map[i].start_pfn >= max_low_pfn) {
+			printk("start_pfn %lu >= %lu\n", early_node_map[i].start_pfn,
+								max_low_pfn);
 			continue;
+		}
 
-		if (end_pfn > max_low_pfn)
+		if (end_pfn > max_low_pfn) {
+			printk("end_pfn %lu going back to %lu\n", early_node_map[i].end_pfn,
+									max_low_pfn);
 			end_pfn = max_low_pfn;
+		}
 
 		size_pages = end_pfn - early_node_map[i].start_pfn;
+		printk("free_bootmem_node(%d, %lu, %lu) :::: pfn ranges (%d, %lu, %lu)\n",
+				early_node_map[i].nid,
+				PFN_PHYS(early_node_map[i].start_pfn),
+				PFN_PHYS(size_pages),
+				early_node_map[i].nid, early_node_map[i].start_pfn, end_pfn);
 		free_bootmem_node(NODE_DATA(early_node_map[i].nid),
 				PFN_PHYS(early_node_map[i].start_pfn),
 				PFN_PHYS(size_pages));
@@ -661,10 +673,15 @@ void __init free_bootmem_with_active_reg
 void __init sparse_memory_present_with_active_regions(int nid)
 {
 	unsigned int i;
-	for_each_active_range_index_in_nid(i, nid)
+	for_each_active_range_index_in_nid(i, nid) {
+		printk("memory_present(%d, %lu, %lu)\n",
+			early_node_map[i].nid,
+			early_node_map[i].start_pfn,
+			early_node_map[i].end_pfn);
 		memory_present(early_node_map[i].nid,
 				early_node_map[i].start_pfn,
 				early_node_map[i].end_pfn);
+	}
 }
 
 void __init get_pfn_range_for_nid(unsigned int nid,
@@ -722,6 +739,8 @@ unsigned long __init __absent_pages_in_r
 	unsigned long prev_end_pfn = 0, hole_pages = 0;
 	unsigned long start_pfn;
 
+	printk("__absent_pages_in_range(%d, %lu, %lu) = ", nid,
+					range_start_pfn, range_end_pfn);
 	/* Find the end_pfn of the first active range of pfns in the node */
 	i = first_active_region_index_in_nid(nid);
 	prev_end_pfn = early_node_map[i].start_pfn;
@@ -749,6 +768,8 @@ unsigned long __init __absent_pages_in_r
 		prev_end_pfn = early_node_map[i].end_pfn;
 	}
 
+	printk("%lu\n", hole_pages);
+
 	return hole_pages;
 }
 
@@ -911,6 +932,9 @@ void __init add_active_range(unsigned in
 {
 	unsigned int i;
 
+	printk("add_active_range(%d, %lu, %lu): ",
+			nid, start_pfn, end_pfn);
+
 	/* Merge with existing active regions if possible */
 	for (i = 0; early_node_map[i].end_pfn; i++) {
 		if (early_node_map[i].nid != nid)
@@ -918,12 +942,15 @@ void __init add_active_range(unsigned in
 
 		/* Skip if an existing region covers this new one */
 		if (start_pfn >= early_node_map[i].start_pfn &&
-				end_pfn <= early_node_map[i].end_pfn)
+				end_pfn <= early_node_map[i].end_pfn) {
+			printk("Existing\n");
 			return;
+		}
 
 		/* Merge forward if suitable */
 		if (start_pfn <= early_node_map[i].end_pfn &&
 				end_pfn > early_node_map[i].end_pfn) {
+			printk("Merging forward\n");
 			early_node_map[i].end_pfn = end_pfn;
 			return;
 		}
@@ -931,6 +958,7 @@ void __init add_active_range(unsigned in
 		/* Merge backward if suitable */
 		if (start_pfn < early_node_map[i].end_pfn &&
 				end_pfn >= early_node_map[i].start_pfn) {
+			printk("Merging backwards\n");
 			early_node_map[i].start_pfn = start_pfn;
 			return;
 		}
@@ -942,6 +970,7 @@ void __init add_active_range(unsigned in
 		return;
 	}
 
+	printk("New\n");
 	early_node_map[i].nid = nid;
 	early_node_map[i].start_pfn = start_pfn;
 	early_node_map[i].end_pfn = end_pfn;
@@ -971,6 +1000,14 @@ static void __init sort_node_map(void)
 
 	sort(early_node_map, num, sizeof(struct node_active_region),
 						cmp_node_active_region, NULL);
+
+	printk("Dumping sorted node map\n");
+	for (num = 0; early_node_map[num].end_pfn; num++) {
+		printk("entry %lu: %d  %lu -> %lu\n", num,
+				early_node_map[num].nid,
+				early_node_map[num].start_pfn,
+				early_node_map[num].end_pfn);
+	}
 }
 
 /* Find the lowest pfn for a node. This depends on a sorted early_node_map */
@@ -1012,6 +1049,10 @@ void __init free_area_init_nodes(unsigne
 	unsigned long nid;
 	int zone_index;
 
+	printk("free_area_init_nodes(%lu, %lu, %lu, %lu)\n",
+			arch_max_dma_pfn, arch_max_dma32_pfn,
+			arch_max_low_pfn, arch_max_high_pfn);
+
 	/* Record where the zone boundaries are */
 	memset(arch_zone_lowest_possible_pfn, 0,
 				sizeof(arch_zone_lowest_possible_pfn));
@@ -1028,6 +1069,8 @@ void __init free_area_init_nodes(unsigne
 			arch_zone_highest_possible_pfn[zone_index-1];
 	}
 
+	printk("free_area_init_nodes(): find_min_pfn = %lu\n", find_min_pfn_with_active_regions());
+
 	/* Regions in the early_node_map can be in any order */
 	sort_node_map();