Re: [PATCH] stats: Add a function to report completion latency percentiles

[Jens Axboe <jaxboe@fusionio.com>]

On 2011-08-15 08:54, Jens Axboe wrote:
> On 2011-08-15 05:56, Zhu Yanhai wrote:
>> Hi,
>> This commit breaks the calculation of iops.
>> Before this commit, the iops from group_report is 1467, see below:
>>
>> chenyun@test023057.sqa.cm4 fio]$ sudo ./fio ~/iotest/readdev
>> thread16: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=sync, iodepth=1
>> ...
>> thread16: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=sync, iodepth=1
>> fio 1.57
>> Starting 10 threads
>> Jobs: 10 (f=10): [rrrrrrrrrr] [100.0% done] [5929K/0K /s] [1447 /0
>> iops] [eta 00m:00s]
>> thread16: (groupid=0, jobs=10): err= 0: pid=19538
>>   read : io=176212KB, bw=5871.6KB/s, iops=1467 , runt= 30011msec
>> [cut here]
>>
>>
>> After this commit, the reported iops is 266, which is only one thread's output,
>> not group_reporting, see below:
>>
>> [chenyun@test023057.sqa.cm4 fio]$ sudo ./fio ~/iotest/readdev
>> thread16: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=sync, iodepth=1
>> ...
>> thread16: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=sync, iodepth=1
>> fio 1.57
>> Starting 10 threads
>> Jobs: 10 (f=10): [rrrrrrrrrr] [100.0% done] [6033K/0K /s] [1473 /0
>> iops] [eta 00m:00s]
>> thread16: (groupid=0, jobs=10): err= 0: pid=19692
>>   read : io=351720KB, bw=1065.7KB/s, iops=266 , runt=330046msec
>> [cut here]
> 
> The patch does indeed appear to have broken output for more than 1
> thread in general, even without group_reporting things are not right. It
> also crashes here for me now:

Zhu, does this work for you?

diff --git a/fio.h b/fio.h
index 6766351..c741162 100644
--- a/fio.h
+++ b/fio.h
@@ -217,7 +217,7 @@ struct thread_stat {
 	unsigned int io_u_complete[FIO_IO_U_MAP_NR];
 	unsigned int io_u_lat_u[FIO_IO_U_LAT_U_NR];
 	unsigned int io_u_lat_m[FIO_IO_U_LAT_M_NR];
-	unsigned int io_u_plat [2][FIO_IO_U_PLAT_NR];
+	unsigned int io_u_plat[3][FIO_IO_U_PLAT_NR];
 	unsigned long total_io_u[3];
 	unsigned long short_io_u[3];
 	unsigned long total_submit;

-- 
Jens Axboe