Hello,
I use multiple threads for read and write tests, and use group
reporting to see each thread's stats. So in my output file, I have
something like this:
-----
JOB: (groupid=0, jobs=1): err= 0: pid=17829: Tue Oct 21 12:36:24 2014
Description : [foo]
write: io=12288MB, bw=30371KB/s, iops=59 , runt=414309msec
clat (usec): min=297 , max=30868K, avg=16722.93, stdev=321816.10
lat (usec): min=297 , max=30868K, avg=16723.20, stdev=321816.11
clat percentiles (usec):
| 1.00th=[ 326], 5.00th=[ 334], 10.00th=[ 338], 20.00th=[ 342],
| 30.00th=[ 350], 40.00th=[ 358], 50.00th=[ 366], 60.00th=[ 386],
| 70.00th=[ 410], 80.00th=[ 486], 90.00th=[ 572], 95.00th=[ 668],
| 99.00th=[45824], 99.50th=[626688], 99.90th=[4554752], 99.95th=[5865472],
| 99.99th=[10289152]
bw (KB/s) : min= 16, max=1002496, per=32.23%, avg=78205.35,
stdev=182341.44
lat (usec) : 500=82.77%, 750=13.07%, 1000=0.68%
lat (msec) : 2=1.42%, 4=0.44%, 10=0.15%, 20=0.23%, 50=0.26%
lat (msec) : 100=0.15%, 250=0.14%, 500=0.13%, 750=0.09%, 1000=0.08%
lat (msec) : 2000=0.15%, >=2000=0.24%
cpu : usr=0.77%, sys=2.91%, ctx=24853, majf=0, minf=4
IO depths : 1=100.0%, 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=0/w=24576/d=0, short=r=0/w=0/d=0
… (another thread) …
… (another thread) ...
Run status group 0 (all jobs):
WRITE: io=98304MB, aggrb=242665KB/s, minb=30333KB/s, maxb=44320KB/s,
mint=283908msec, maxt=414823msec
-----
If I go through and parse each "write" line (in this example), and add
up all the "bw=" numbers, that does not equal the "aggrb" number
reported at the end (it's higher by about 15%).
I thought "aggrb" would just be a rollup of all the individual
thread's bandwidth, so I'm having a hard time determining why the two
numbers don't match. Maybe my basic assumption is incorrect, and if
that's true then which numbers are correct -- the per-thread numbers,
or the aggregate number?
Thanks for any help…
--gs
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