Messages in this thread | | | Date | Mon, 9 Sep 2019 15:32:36 +1000 | From | Dave Chinner <> | Subject | Re: [xfs] 610125ab1e: fsmark.app_overhead -71.2% improvement |
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On Mon, Sep 09, 2019 at 09:58:49AM +0800, kernel test robot wrote: > Greeting, > > FYI, we noticed a -71.2% improvement of fsmark.app_overhead due to commit:
A negative improvement? That's somewhat ambiguous...
> 0e822255f95db400 610125ab1e4b1b48dcffe74d9d8 > ---------------- --------------------------- > %stddev %change %stddev > \ | \ > 1.095e+08 -71.2% 31557568 fsmark.app_overhead > 6157 +95.5% 12034 fsmark.files_per_sec
So, the files/s rate doubled, and the amount of time spent in userspace by the fsmark app dropped by 70%.
> 167.31 -47.3% 88.25 fsmark.time.elapsed_time > 167.31 -47.3% 88.25 fsmark.time.elapsed_time.max
Wall time went down by 50%.
> 91.00 -8.8% 83.00 fsmark.time.percent_of_cpu_this_job_got > 148.15 -53.2% 69.38 fsmark.time.system_time
As did system CPU.
IOWs, this change has changed create performance by a factor of 4 - the file create is 2x faster for half the CPU spent.
I don't think this is a negative improvement - it's a large positive improvement. I suspect that you need to change the metric classifications for this workload...
Cheers,
Dave. -- Dave Chinner dchinner@redhat.com
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