[PATCH 09/10] mm: expose BDI statistics in sysfs.

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

[-- Attachment #1: bdi_stat_sysfs.patch --]
[-- Type: text/plain, Size: 1814 bytes --]

Expose the per BDI stats in /sys/block/<dev>/queue/*

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
 block/ll_rw_blk.c |   32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

Index: linux-2.6-mm/block/ll_rw_blk.c
===================================================================
--- linux-2.6-mm.orig/block/ll_rw_blk.c
+++ linux-2.6-mm/block/ll_rw_blk.c
@@ -3976,6 +3976,15 @@ static ssize_t queue_max_hw_sectors_show
 	return queue_var_show(max_hw_sectors_kb, (page));
 }
 
+static ssize_t queue_nr_reclaimable_show(struct request_queue *q, char *page)
+{
+	return sprintf(page, "%lld\n", bdi_stat(&q->backing_dev_info, BDI_RECLAIMABLE));
+}
+
+static ssize_t queue_nr_writeback_show(struct request_queue *q, char *page)
+{
+	return sprintf(page, "%lld\n", bdi_stat(&q->backing_dev_info, BDI_WRITEBACK));
+}
 
 static struct queue_sysfs_entry queue_requests_entry = {
 	.attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
@@ -4006,6 +4020,16 @@ static struct queue_sysfs_entry queue_ma
 	.show = queue_max_hw_sectors_show,
 };
 
+static struct queue_sysfs_entry queue_reclaimable_entry = {
+	.attr = {.name = "reclaimable_pages", .mode = S_IRUGO },
+	.show = queue_nr_reclaimable_show,
+};
+
+static struct queue_sysfs_entry queue_writeback_entry = {
+	.attr = {.name = "writeback_pages", .mode = S_IRUGO },
+	.show = queue_nr_writeback_show,
+};
+
 static struct queue_sysfs_entry queue_iosched_entry = {
 	.attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
 	.show = elv_iosched_show,
@@ -4018,6 +4047,8 @@ static struct attribute *default_attrs[]
 	&queue_initial_ra_entry.attr,
 	&queue_max_hw_sectors_entry.attr,
 	&queue_max_sectors_entry.attr,
+	&queue_reclaimable_entry.attr,
+	&queue_writeback_entry.attr,
 	&queue_iosched_entry.attr,
 	NULL,
 };

--