[PATCH 23/23] debug: sysfs files for the current ratio/size/total

From: Peter Zijlstra
Date: Fri Aug 03 2007 - 09:03:18 EST


Expose the per bdi dirty limits in sysfs

Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
---
block/ll_rw_blk.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++
mm/page-writeback.c | 4 +-
2 files changed, 82 insertions(+), 2 deletions(-)

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
@@ -3995,6 +3995,56 @@ static ssize_t queue_nr_writeback_show(s
nr_writeback >> (PAGE_CACHE_SHIFT - 10));
}

+extern void bdi_writeout_fraction(struct backing_dev_info *bdi,
+ long *numerator, long *denominator);
+
+static ssize_t queue_nr_cache_ratio_show(struct request_queue *q, char *page)
+{
+ long scale, div;
+
+ bdi_writeout_fraction(&q->backing_dev_info, &scale, &div);
+ scale *= 1024;
+ scale /= div;
+
+ return sprintf(page, "%ld\n", scale);
+}
+
+static ssize_t queue_nr_cache_num_show(struct request_queue *q, char *page)
+{
+ long scale, div;
+
+ bdi_writeout_fraction(&q->backing_dev_info, &scale, &div);
+
+ return sprintf(page, "%ld\n", scale);
+}
+
+static ssize_t queue_nr_cache_denom_show(struct request_queue *q, char *page)
+{
+ long scale, div;
+
+ bdi_writeout_fraction(&q->backing_dev_info, &scale, &div);
+
+ return sprintf(page, "%ld\n", div);
+}
+
+extern void
+get_dirty_limits(long *pbackground, long *pdirty, long *pbdi_dirty,
+ struct backing_dev_info *bdi);
+
+static ssize_t queue_nr_cache_size_show(struct request_queue *q, char *page)
+{
+ long background, dirty, bdi_dirty;
+ get_dirty_limits(&background, &dirty, &bdi_dirty, &q->backing_dev_info);
+ return sprintf(page, "%ld\n", bdi_dirty);
+}
+
+static ssize_t queue_nr_cache_total_show(struct request_queue *q, char *page)
+{
+ long background, dirty, bdi_dirty;
+ get_dirty_limits(&background, &dirty, &bdi_dirty, &q->backing_dev_info);
+ return sprintf(page, "%ld\n", dirty);
+}
+
static struct queue_sysfs_entry queue_requests_entry = {
.attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
.show = queue_requests_show,
@@ -4028,6 +4078,31 @@ static struct queue_sysfs_entry queue_wr
.show = queue_nr_writeback_show,
};

+static struct queue_sysfs_entry queue_cache_ratio_entry = {
+ .attr = {.name = "cache_ratio", .mode = S_IRUGO },
+ .show = queue_nr_cache_ratio_show,
+};
+
+static struct queue_sysfs_entry queue_cache_num_entry = {
+ .attr = {.name = "cache_num", .mode = S_IRUGO },
+ .show = queue_nr_cache_num_show,
+};
+
+static struct queue_sysfs_entry queue_cache_denom_entry = {
+ .attr = {.name = "cache_denom", .mode = S_IRUGO },
+ .show = queue_nr_cache_denom_show,
+};
+
+static struct queue_sysfs_entry queue_cache_size_entry = {
+ .attr = {.name = "cache_size", .mode = S_IRUGO },
+ .show = queue_nr_cache_size_show,
+};
+
+static struct queue_sysfs_entry queue_cache_total_entry = {
+ .attr = {.name = "cache_total", .mode = S_IRUGO },
+ .show = queue_nr_cache_total_show,
+};
+
static struct queue_sysfs_entry queue_iosched_entry = {
.attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
.show = elv_iosched_show,
@@ -4041,6 +4116,11 @@ static struct attribute *default_attrs[]
&queue_max_sectors_entry.attr,
&queue_reclaimable_entry.attr,
&queue_writeback_entry.attr,
+ &queue_cache_ratio_entry.attr,
+ &queue_cache_num_entry.attr,
+ &queue_cache_denom_entry.attr,
+ &queue_cache_size_entry.attr,
+ &queue_cache_total_entry.attr,
&queue_iosched_entry.attr,
NULL,
};
Index: linux-2.6/mm/page-writeback.c
===================================================================
--- linux-2.6.orig/mm/page-writeback.c
+++ linux-2.6/mm/page-writeback.c
@@ -176,7 +176,7 @@ static void task_dirty_inc(struct task_s
/*
* Obtain an accurate fraction of the BDI's portion.
*/
-static void bdi_writeout_fraction(struct backing_dev_info *bdi,
+void bdi_writeout_fraction(struct backing_dev_info *bdi,
long *numerator, long *denominator)
{
if (bdi_cap_writeback_dirty(bdi)) {
@@ -300,7 +300,7 @@ static unsigned long determine_dirtyable
return x + 1; /* Ensure that we never return 0 */
}

-static void
+void
get_dirty_limits(long *pbackground, long *pdirty, long *pbdi_dirty,
struct backing_dev_info *bdi)
{

--

-
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