Seperate read and write statistics of in_flight requests
Currently, there is a single in_flight counter measuring the number of
requests in the request_queue. But some monitoring tools would like to
know how many read requests and write requests are in progress. Split the
current in_flight counter into two seperate counters for read and write.
This information is exported as a sysfs attribute, as changing the
currently available stat files would break the existing tools.
Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 45fc320..44263cb 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -98,7 +98,7 @@
int make_it_fail;
#endif
unsigned long stamp;
- int in_flight;
+ int in_flight[2];
#ifdef CONFIG_SMP
struct disk_stats *dkstats;
#else
@@ -322,18 +322,23 @@
#define part_stat_sub(cpu, gendiskp, field, subnd) \
part_stat_add(cpu, gendiskp, field, -subnd)
-static inline void part_inc_in_flight(struct hd_struct *part)
+static inline void part_inc_in_flight(struct hd_struct *part, int rw)
{
- part->in_flight++;
+ part->in_flight[rw]++;
if (part->partno)
- part_to_disk(part)->part0.in_flight++;
+ part_to_disk(part)->part0.in_flight[rw]++;
}
-static inline void part_dec_in_flight(struct hd_struct *part)
+static inline void part_dec_in_flight(struct hd_struct *part, int rw)
{
- part->in_flight--;
+ part->in_flight[rw]--;
if (part->partno)
- part_to_disk(part)->part0.in_flight--;
+ part_to_disk(part)->part0.in_flight[rw]--;
+}
+
+static inline int part_in_flight(struct hd_struct *part)
+{
+ return part->in_flight[0] + part->in_flight[1];
}
/* block/blk-core.c */
@@ -546,6 +551,8 @@
struct device_attribute *attr, char *buf);
extern ssize_t part_stat_show(struct device *dev,
struct device_attribute *attr, char *buf);
+extern ssize_t part_inflight_show(struct device *dev,
+ struct device_attribute *attr, char *buf);
#ifdef CONFIG_FAIL_MAKE_REQUEST
extern ssize_t part_fail_show(struct device *dev,
struct device_attribute *attr, char *buf);