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author | Nikanth Karthikesan <knikanth@suse.de> | 2009-10-06 20:16:55 +0200 |
---|---|---|
committer | Jens Axboe <jens.axboe@oracle.com> | 2009-10-06 20:16:55 +0200 |
commit | 316d315bffa4026f28085f6b24ebcebede370ac7 (patch) | |
tree | 10b6b057fec2382536371d2e14f9d4c0d6cf9eea /include/linux/genhd.h | |
parent | 23e018a1b083ecb4b8bb2fb43d58e7c19b5d7959 (diff) | |
download | linux-stable-316d315bffa4026f28085f6b24ebcebede370ac7.tar.gz linux-stable-316d315bffa4026f28085f6b24ebcebede370ac7.tar.bz2 linux-stable-316d315bffa4026f28085f6b24ebcebede370ac7.zip |
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.h | 21 |
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); |