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authorNikanth Karthikesan <knikanth@suse.de>2009-10-06 20:16:55 +0200
committerJens Axboe <jens.axboe@oracle.com>2009-10-06 20:16:55 +0200
commit316d315bffa4026f28085f6b24ebcebede370ac7 (patch)
tree10b6b057fec2382536371d2e14f9d4c0d6cf9eea /include/linux/genhd.h
parent23e018a1b083ecb4b8bb2fb43d58e7c19b5d7959 (diff)
block: Seperate read and write statistics of in_flight requests v2
Commit a9327cac440be4d8333bba975cbbf76045096275 added seperate read and write statistics of in_flight requests. And exported the number of read and write requests in progress seperately through sysfs. But Corrado Zoccolo <czoccolo@gmail.com> reported getting strange output from "iostat -kx 2". Global values for service time and utilization were garbage. For interval values, utilization was always 100%, and service time is higher than normal. So this was reverted by commit 0f78ab9899e9d6acb09d5465def618704255963b The problem was in part_round_stats_single(), I missed the following: if (now == part->stamp) return; - if (part->in_flight) { + if (part_in_flight(part)) { __part_stat_add(cpu, part, time_in_queue, part_in_flight(part) * (now - part->stamp)); __part_stat_add(cpu, part, io_ticks, (now - part->stamp)); With this chunk included, the reported regression gets fixed. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> -- Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'include/linux/genhd.h')
-rw-r--r--include/linux/genhd.h21
1 files changed, 14 insertions, 7 deletions
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 7beaa21b3880..297df45ffd0a 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -98,7 +98,7 @@ struct hd_struct {
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 @@ static inline void free_part_stats(struct hd_struct *part)
#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 @@ extern ssize_t part_size_show(struct device *dev,
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);