I saw the response on http://www.spinics.net/lists/fio/msg04392.html (didn't
get the email), so I'm pasting it here.
I git pulled the latest fio code and observed the specified changes. I
compiled and ran the latest code but still seeing the same problem:
===============
test: (g=0): rw=randread, bs=4K-4K/4K-4K/4K-4K, ioengine=libaio, iodepth=1
fio-2.2.12-50-g5261
Starting 1 thread
test: (groupid=0, jobs=1): err= 0: pid=10726: Tue Dec 8 13:40:21 2015
read : io=799740KB, bw=79966KB/s, iops=19991, runt= 10001msec
slat (usec): min=0, max=11, avg= 0.10, stdev= 0.30
clat (usec): min=26, max=2624, avg=49.03, stdev=34.07
lat (usec): min=35, max=2624, avg=49.12, stdev=34.07
clat percentiles (usec):
| 1.00th=[ 36], 5.00th=[ 36], 10.00th=[ 36], 20.00th=[ 37],
| 30.00th=[ 37], 40.00th=[ 38], 50.00th=[ 38], 60.00th=[ 39],
| 70.00th=[ 40], 80.00th=[ 70], 90.00th=[ 79], 95.00th=[ 87],
| 99.00th=[ 92], 99.50th=[ 94], 99.90th=[ 225], 99.95th=[ 298],
| 99.99th=[ 2128]
bw (KB /s): min= 0, max=81072, per=95.01%, avg=75974.80, stdev=17896.56
lat (usec) : 50=71.32%, 100=28.42%, 250=0.19%, 500=0.04%, 750=0.01%
lat (usec) : 1000=0.01%
lat (msec) : 2=0.01%, 4=0.01%
cpu : usr=99.99%, sys=0.00%, ctx=8, majf=0, minf=0
IO depths : 1=157.5%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
issued : total=r=199935/w=0/d=0, short=r=0/w=0/d=0, drop=r=0/w=0/d=0
latency : target=0, window=0, percentile=100.00%, depth=1
Run status group 0 (all jobs):
READ: io=799740KB, aggrb=79966KB/s, minb=79966KB/s, maxb=79966KB/s,
mint=10001msec, maxt=10001msec
===============
Jens Axboe wrote:
On 11/25/2015 12:36 PM, Deyoung Hong (dhong) wrote:
> I think this is an fio bug.
>
> Description: When specifying ramp_time, cpu may show over 100% (when using
> a polling mode driver).
> If ramp_time is not specified, cpu values appear to be correct.
> You normally don't see this problem because most drivers don't utilize high
> CPU usage.
> You will have to use some custom driver that does polling, for example
> (something like http://www.dpdk.org/).
>
> OS: Any (but tested on Linux CentOS 6.6)
This should fix it:
http://git.kernel.dk/cgit/fio/commit/?id=210dd0fc66b8956065e098bb9314febe8993e849
Try current -git and hopefully it'll behave better.
--
Jens Axboe
--
To unsubscribe from this list: send the line "unsubscribe fio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe fio" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
