[PATCH 19/23] mm: expose BDI statistics in sysfs.

From: Peter Zijlstra
Date: Tue Sep 11 2007 - 16:17:48 EST


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

Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
---
block/ll_rw_blk.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)

Index: linux-2.6/block/ll_rw_blk.c
===================================================================
--- linux-2.6.orig/block/ll_rw_blk.c
+++ linux-2.6/block/ll_rw_blk.c
@@ -4098,6 +4098,24 @@ static ssize_t queue_max_segments_show(s
return queue_var_show(q->max_phys_segments, page);
}

+static ssize_t queue_nr_reclaimable_show(struct request_queue *q, char *page)
+{
+ unsigned long long nr_reclaimable =
+ bdi_stat(&q->backing_dev_info, BDI_RECLAIMABLE);
+
+ return sprintf(page, "%llu\n",
+ nr_reclaimable >> (PAGE_CACHE_SHIFT - 10));
+}
+
+static ssize_t queue_nr_writeback_show(struct request_queue *q, char *page)
+{
+ unsigned long long nr_writeback =
+ bdi_stat(&q->backing_dev_info, BDI_WRITEBACK);
+
+ return sprintf(page, "%llu\n",
+ nr_writeback >> (PAGE_CACHE_SHIFT - 10));
+}
+
static ssize_t queue_max_segments_store(struct request_queue *q,
const char *page, size_t count)
{
@@ -4139,6 +4157,16 @@ static struct queue_sysfs_entry queue_ma
.store = queue_max_segments_store,
};

+static struct queue_sysfs_entry queue_reclaimable_entry = {
+ .attr = {.name = "reclaimable_kb", .mode = S_IRUGO },
+ .show = queue_nr_reclaimable_show,
+};
+
+static struct queue_sysfs_entry queue_writeback_entry = {
+ .attr = {.name = "writeback_kb", .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,
@@ -4151,6 +4179,8 @@ static struct attribute *default_attrs[]
&queue_max_hw_sectors_entry.attr,
&queue_max_sectors_entry.attr,
&queue_max_segments_entry.attr,
+ &queue_reclaimable_entry.attr,
+ &queue_writeback_entry.attr,
&queue_iosched_entry.attr,
NULL,
};

--

-
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