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-rw-r--r--block/blk-sysfs.c151
1 files changed, 151 insertions, 0 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index f87a7e747..85c3dc223 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -10,6 +10,7 @@
#include <linux/blktrace_api.h>
#include <linux/blk-mq.h>
#include <linux/blk-cgroup.h>
+#include <linux/wbt.h>
#include "blk.h"
#include "blk-mq.h"
@@ -41,6 +42,19 @@ queue_var_store(unsigned long *var, const char *page, size_t count)
return count;
}
+static ssize_t queue_var_store64(u64 *var, const char *page)
+{
+ int err;
+ u64 v;
+
+ err = kstrtou64(page, 10, &v);
+ if (err < 0)
+ return err;
+
+ *var = v;
+ return 0;
+}
+
static ssize_t queue_requests_show(struct request_queue *q, char *page)
{
return queue_var_show(q->nr_requests, (page));
@@ -347,6 +361,58 @@ static ssize_t queue_poll_store(struct request_queue *q, const char *page,
return ret;
}
+static ssize_t queue_wb_win_show(struct request_queue *q, char *page)
+{
+ if (!q->rq_wb)
+ return -EINVAL;
+
+ return sprintf(page, "%llu\n", div_u64(q->rq_wb->win_nsec, 1000));
+}
+
+static ssize_t queue_wb_win_store(struct request_queue *q, const char *page,
+ size_t count)
+{
+ ssize_t ret;
+ u64 val;
+
+ if (!q->rq_wb)
+ return -EINVAL;
+
+ ret = queue_var_store64(&val, page);
+ if (ret < 0)
+ return ret;
+
+ q->rq_wb->win_nsec = val * 1000ULL;
+ wbt_update_limits(q->rq_wb);
+ return count;
+}
+
+static ssize_t queue_wb_lat_show(struct request_queue *q, char *page)
+{
+ if (!q->rq_wb)
+ return -EINVAL;
+
+ return sprintf(page, "%llu\n", div_u64(q->rq_wb->min_lat_nsec, 1000));
+}
+
+static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
+ size_t count)
+{
+ ssize_t ret;
+ u64 val;
+
+ if (!q->rq_wb)
+ return -EINVAL;
+
+ ret = queue_var_store64(&val, page);
+ if (ret < 0)
+ return ret;
+
+ q->rq_wb->min_lat_nsec = val * 1000ULL;
+ wbt_update_limits(q->rq_wb);
+ return count;
+}
+
static ssize_t queue_wc_show(struct request_queue *q, char *page)
{
if (test_bit(QUEUE_FLAG_WC, &q->queue_flags))
@@ -384,6 +450,26 @@ static ssize_t queue_dax_show(struct request_queue *q, char *page)
return queue_var_show(blk_queue_dax(q), page);
}
+static ssize_t print_stat(char *page, struct blk_rq_stat *stat, const char *pre)
+{
+ return sprintf(page, "%s samples=%llu, mean=%lld, min=%lld, max=%lld\n",
+ pre, (long long) stat->nr_samples,
+ (long long) stat->mean, (long long) stat->min,
+ (long long) stat->max);
+}
+
+static ssize_t queue_stats_show(struct request_queue *q, char *page)
+{
+ struct blk_rq_stat stat[2];
+ ssize_t ret;
+
+ blk_queue_stat_get(q, stat);
+
+ ret = print_stat(page, &stat[0], "read :");
+ ret += print_stat(page + ret, &stat[1], "write:");
+ return ret;
+}
+
static struct queue_sysfs_entry queue_requests_entry = {
.attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
.show = queue_requests_show,
@@ -526,6 +612,23 @@ static struct queue_sysfs_entry queue_dax_entry = {
.show = queue_dax_show,
};
+static struct queue_sysfs_entry queue_stats_entry = {
+ .attr = {.name = "stats", .mode = S_IRUGO },
+ .show = queue_stats_show,
+};
+
+static struct queue_sysfs_entry queue_wb_lat_entry = {
+ .attr = {.name = "wbt_lat_usec", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_wb_lat_show,
+ .store = queue_wb_lat_store,
+};
+
+static struct queue_sysfs_entry queue_wb_win_entry = {
+ .attr = {.name = "wbt_window_usec", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_wb_win_show,
+ .store = queue_wb_win_store,
+};
+
static struct attribute *default_attrs[] = {
&queue_requests_entry.attr,
&queue_ra_entry.attr,
@@ -553,6 +656,9 @@ static struct attribute *default_attrs[] = {
&queue_poll_entry.attr,
&queue_wc_entry.attr,
&queue_dax_entry.attr,
+ &queue_stats_entry.attr,
+ &queue_wb_lat_entry.attr,
+ &queue_wb_win_entry.attr,
NULL,
};
@@ -667,6 +773,49 @@ struct kobj_type blk_queue_ktype = {
.release = blk_release_queue,
};
+static void blk_wb_stat_get(void *data, struct blk_rq_stat *stat)
+{
+ blk_queue_stat_get(data, stat);
+}
+
+static void blk_wb_stat_clear(void *data)
+{
+ blk_stat_clear(data);
+}
+
+static bool blk_wb_stat_is_current(struct blk_rq_stat *stat)
+{
+ return blk_stat_is_current(stat);
+}
+
+static struct wb_stat_ops wb_stat_ops = {
+ .get = blk_wb_stat_get,
+ .is_current = blk_wb_stat_is_current,
+ .clear = blk_wb_stat_clear,
+};
+
+static void blk_wb_init(struct request_queue *q)
+{
+ struct rq_wb *rwb;
+
+ rwb = wbt_init(&q->backing_dev_info, &wb_stat_ops, q);
+
+ /*
+ * If this fails, we don't get throttling
+ */
+ if (IS_ERR(rwb))
+ return;
+
+ if (blk_queue_nonrot(q))
+ rwb->min_lat_nsec = 2000000ULL;
+ else
+ rwb->min_lat_nsec = 75000000ULL;
+
+ wbt_set_queue_depth(rwb, blk_queue_depth(q));
+ wbt_set_write_cache(rwb, test_bit(QUEUE_FLAG_WC, &q->queue_flags));
+ q->rq_wb = rwb;
+}
+
int blk_register_queue(struct gendisk *disk)
{
int ret;
@@ -706,6 +855,8 @@ int blk_register_queue(struct gendisk *disk)
if (q->mq_ops)
blk_mq_register_disk(disk);
+ blk_wb_init(q);
+
if (!q->request_fn)
return 0;