X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=mm%2Fvmstat.c;h=7759941d4e7760616e1bf89c0ed887f485b473a9;hb=105a048a4f35f7a74c7cc20b36dd83658b6ec232;hp=d3e0fa169f05bbedc7a0cd222a4e55f3fac1cfca;hpb=d7a5752c0c19750312efab3a2a80d350e11fa4a2;p=safe%2Fjmp%2Flinux-2.6

diff --git a/mm/vmstat.c b/mm/vmstat.c
index d3e0fa1..7759941 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -16,6 +16,7 @@
 #include <linux/cpu.h>
 #include <linux/vmstat.h>
 #include <linux/sched.h>
+#include <linux/math64.h>
 
 #ifdef CONFIG_VM_EVENT_COUNTERS
 DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
@@ -420,6 +421,42 @@ static void fill_contig_page_info(struct zone *zone,
 						(order - suitable_order);
 	}
 }
+
+/*
+ * A fragmentation index only makes sense if an allocation of a requested
+ * size would fail. If that is true, the fragmentation index indicates
+ * whether external fragmentation or a lack of memory was the problem.
+ * The value can be used to determine if page reclaim or compaction
+ * should be used
+ */
+static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
+{
+	unsigned long requested = 1UL << order;
+
+	if (!info->free_blocks_total)
+		return 0;
+
+	/* Fragmentation index only makes sense when a request would fail */
+	if (info->free_blocks_suitable)
+		return -1000;
+
+	/*
+	 * Index is between 0 and 1 so return within 3 decimal places
+	 *
+	 * 0 => allocation would fail due to lack of memory
+	 * 1 => allocation would fail due to fragmentation
+	 */
+	return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
+}
+
+/* Same as __fragmentation index but allocs contig_page_info on stack */
+int fragmentation_index(struct zone *zone, unsigned int order)
+{
+	struct contig_page_info info;
+
+	fill_contig_page_info(zone, order, &info);
+	return __fragmentation_index(order, &info);
+}
 #endif
 
 #if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
@@ -738,6 +775,16 @@ static const char * const vmstat_text[] = {
 	"allocstall",
 
 	"pgrotated",
+
+#ifdef CONFIG_COMPACTION
+	"compact_blocks_moved",
+	"compact_pages_moved",
+	"compact_pagemigrate_failed",
+	"compact_stall",
+	"compact_fail",
+	"compact_success",
+#endif
+
 #ifdef CONFIG_HUGETLB_PAGE
 	"htlb_buddy_alloc_success",
 	"htlb_buddy_alloc_fail",
@@ -1087,6 +1134,58 @@ static const struct file_operations unusable_file_ops = {
 	.release	= seq_release,
 };
 
+static void extfrag_show_print(struct seq_file *m,
+					pg_data_t *pgdat, struct zone *zone)
+{
+	unsigned int order;
+	int index;
+
+	/* Alloc on stack as interrupts are disabled for zone walk */
+	struct contig_page_info info;
+
+	seq_printf(m, "Node %d, zone %8s ",
+				pgdat->node_id,
+				zone->name);
+	for (order = 0; order < MAX_ORDER; ++order) {
+		fill_contig_page_info(zone, order, &info);
+		index = __fragmentation_index(order, &info);
+		seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
+	}
+
+	seq_putc(m, '\n');
+}
+
+/*
+ * Display fragmentation index for orders that allocations would fail for
+ */
+static int extfrag_show(struct seq_file *m, void *arg)
+{
+	pg_data_t *pgdat = (pg_data_t *)arg;
+
+	walk_zones_in_node(m, pgdat, extfrag_show_print);
+
+	return 0;
+}
+
+static const struct seq_operations extfrag_op = {
+	.start	= frag_start,
+	.next	= frag_next,
+	.stop	= frag_stop,
+	.show	= extfrag_show,
+};
+
+static int extfrag_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &extfrag_op);
+}
+
+static const struct file_operations extfrag_file_ops = {
+	.open		= extfrag_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
 static int __init extfrag_debug_init(void)
 {
 	extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
@@ -1097,6 +1196,10 @@ static int __init extfrag_debug_init(void)
 			extfrag_debug_root, NULL, &unusable_file_ops))
 		return -ENOMEM;
 
+	if (!debugfs_create_file("extfrag_index", 0444,
+			extfrag_debug_root, NULL, &extfrag_file_ops))
+		return -ENOMEM;
+
 	return 0;
 }