On 06/09/2014 08:40 PM, Fam Zheng wrote:
On Mon, 06/09 15:43, Karl Rister wrote:
Hi All
I was asked by our development team to do a performance sniff test of the
latest dataplane code on s390 and compare it against qemu.git. Here is a
brief description of the configuration, the testing done, and then the
results.
Configuration:
Host: 26 CPU LPAR, 64GB, 8 zFCP adapters
Guest: 4 VCPU, 1GB, 128 virtio block devices
Each virtio block device maps to a dm-multipath device in the host with 8
paths. Multipath is configured with the service-time policy. All block
devices are configured to use the deadline IO scheduler.
Test:
FIO is used to run 4 scenarios: sequential read, sequential write, random
read, and random write. Sequential scenarios use a 128KB request size and
random scenarios us a 8KB request size. Each scenario is run with an
increasing number of jobs, from 1 to 128 (powers of 2). Each job is bound
to an individual file on an ext3 file system on a virtio device and uses
O_DIRECT, libaio, and iodepth=1. Each test is run three times for 2 minutes
each, the first iteration (a warmup) is thrown out and the next two
iterations are averaged together.
Results:
Baseline: qemu.git 93f94f9018229f146ed6bbe9e5ff72d67e4bd7ab
Dataplane: bdrv_set_aio_context 0ab50cde71aa27f39b8a3ea4766ff82671adb2a4
Hi Karl,
Thanks for the results.
The throughput differences look minimal, where is the bandwidth saturated in
these tests? And why use iodepth=1, not more?
Hi Fam
Based on previously collected data, the configuration is hitting
saturation at the following points:
Sequential Read: 128 jobs
Sequential Write: 32 jobs
Random Read: 64 jobs
Random Write: saturation not reached
The iodepth=1 configuration is a somewhat arbitrary choice that is only
limited by machine run time, I could certainly run higher loads and at
times I do.
Thanks.
Karl
Thanks,
Fam
Sequential Read:
Overall a slight throughput regression with a noticeable reduction in CPU
efficiency.
1 Job: Throughput regressed -1.4%, CPU improved -0.83%.
2 Job: Throughput regressed -2.5%, CPU regressed +2.81%
4 Job: Throughput regressed -2.2%, CPU regressed +12.22%
8 Job: Throughput regressed -0.7%, CPU regressed +9.77%
16 Job: Throughput regressed -3.4%, CPU regressed +7.04%
32 Job: Throughput regressed -1.8%, CPU regressed +12.03%
64 Job: Throughput regressed -0.1%, CPU regressed +10.60%
128 Job: Throughput increased +0.3%, CPU regressed +10.70%
Sequential Write:
Mostly regressed throughput, although it gets better as job count increases
and even has some gains at higher job counts. CPU efficiency is regressed.
1 Job: Throughput regressed -1.9%, CPU regressed +0.90%
2 Job: Throughput regressed -2.0%, CPU regressed +1.07%
4 Job: Throughput regressed -2.4%, CPU regressed +8.68%
8 Job: Throughput regressed -2.0%, CPU regressed +4.23%
16 Job: Throughput regressed -5.0%, CPU regressed +10.53%
32 Job: Throughput improved +7.6%, CPU regressed +7.37%
64 Job: Throughput regressed -0.6%, CPU regressed +7.29%
128 Job: Throughput improved +8.3%, CPU regressed +6.68%
Random Read:
Again, mostly throughput regressions except for the largest job counts. CPU
efficiency is regressed at all data points.
1 Job: Throughput regressed -3.0%, CPU regressed +0.14%
2 Job: Throughput regressed -3.6%, CPU regressed +6.86%
4 Job: Throughput regressed -5.1%, CPU regressed +11.11%
8 Job: Throughput regressed -8.6%, CPU regressed +12.32%
16 Job: Throughput regressed -5.7%, CPU regressed +12.99%
32 Job: Throughput regressed -7.4%, CPU regressed +7.62%
64 Job: Throughput improved +10.0%, CPU regressed +10.83%
128 Job: Throughput improved +10.7%, CPU regressed +10.85%
Random Write:
Throughput and CPU regressed at all but one data point.
1 Job: Throughput regressed -2.3%, CPU improved -1.50%
2 Job: Throughput regressed -2.2%, CPU regressed +0.16%
4 Job: Throughput regressed -1.0%, CPU regressed +8.36%
8 Job: Throughput regressed -8.6%, CPU regressed +12.47%
16 Job: Throughput regressed -3.1%, CPU regressed +12.40%
32 Job: Throughput regressed -0.2%, CPU regressed +11.59%
64 Job: Throughput regressed -1.9%, CPU regressed +12.65%
128 Job: Throughput improved +5.6%, CPU regressed +11.68%
* CPU consumption is an efficiency calculation of usage per MB of
throughput.
--
Karl Rister <k...@us.ibm.com>
IBM Linux/KVM Development Optimization
--
Karl Rister <k...@us.ibm.com>
IBM Linux/KVM Development Optimization
