Messages in this thread | | | From | Alex Shi <> | Subject | [PATCH v4 0/6] sched: use runnable load based balance | Date | Sat, 27 Apr 2013 13:25:38 +0800 |
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This patchset bases on tip/sched/core.
The patchset remove the burst wakeup detection which had worked fine on 3.8 kernel, since the aim7 is very imbalance. But rwsem write lock stealing enabled in 3.9 kernel. aim7 imbalance disappeared. So the burst wakeup care doesn't needed.
It was tested on Intel core2, NHM, SNB, IVB, 2 and 4 sockets machines with benchmark kbuild, aim7, dbench, tbench, hackbench, fileio-cfq(sysbench)
On SNB EP 4 sockets machine, the hackbench increased about 50%, and result become stable. on other machines, hackbench increased about 2~5%. no clear performance change on other benchmarks.
and Michael Wang had tested the pgbench on his box: https://lkml.org/lkml/2013/4/2/1022 --- Done, here the results of pgbench without the last patch on my box:
| db_size | clients | tps | | tps | +---------+---------+-------+ +-------+ | 22 MB | 1 | 10662 | | 10679 | | 22 MB | 2 | 21483 | | 21471 | | 22 MB | 4 | 42046 | | 41957 | | 22 MB | 8 | 55807 | | 55684 | | 22 MB | 12 | 50768 | | 52074 | | 22 MB | 16 | 49880 | | 52879 | | 22 MB | 24 | 45904 | | 53406 | | 22 MB | 32 | 43420 | | 54088 | +24.57% | 7484 MB | 1 | 7965 | | 7725 | | 7484 MB | 2 | 19354 | | 19405 | | 7484 MB | 4 | 37552 | | 37246 | | 7484 MB | 8 | 48655 | | 50613 | | 7484 MB | 12 | 45778 | | 47639 | | 7484 MB | 16 | 45659 | | 48707 | | 7484 MB | 24 | 42192 | | 46469 | | 7484 MB | 32 | 36385 | | 46346 | +27.38% | 15 GB | 1 | 7677 | | 7727 | | 15 GB | 2 | 19227 | | 19199 | | 15 GB | 4 | 37335 | | 37372 | | 15 GB | 8 | 48130 | | 50333 | | 15 GB | 12 | 45393 | | 47590 | | 15 GB | 16 | 45110 | | 48091 | | 15 GB | 24 | 41415 | | 47415 | | 15 GB | 32 | 35988 | | 45749 | +27.12% ---
and also tested by morten.rasmussen@arm.com http://comments.gmane.org/gmane.linux.kernel/1463371 --- The patches are based in 3.9-rc2 and have been tested on an ARM vexpress TC2 big.LITTLE testchip containing five cpus: 2xCortex-A15 + 3xCortex-A7. Additional testing and refinements might be needed later as more sophisticated platforms become available.
cpu_power A15: 1441 cpu_power A7: 606
Benchmarks: cyclictest: cyclictest -a -t 2 -n -D 10 hackbench: hackbench (default settings) sysbench_1t: sysbench --test=cpu --num-threads=1 --max-requests=1000 run sysbench_2t: sysbench --test=cpu --num-threads=2 --max-requests=1000 run sysbench_5t: sysbench --test=cpu --num-threads=5 --max-requests=1000 run
Mixed cpu_power: Average times over 20 runs normalized to 3.9-rc2 (lower is better): 3.9-rc2 +shi +shi+patches Improvement cyclictest AVG 74.9 74.5 75.75 -1.13% MIN 69 69 69 MAX 88 88 94 hackbench AVG 2.17 2.09 2.09 3.90% MIN 2.10 1.95 2.02 MAX 2.25 2.48 2.17 sysbench_1t AVG 25.13* 16.47' 16.48 34.43% MIN 16.47 16.47 16.47 MAX 33.78 16.48 16.54 sysbench_2t AVG 19.32 18.19 16.51 14.55% MIN 16.48 16.47 16.47 MAX 22.15 22.19 16.61 sysbench_5t AVG 27.22 27.71 24.14 11.31% MIN 25.42 27.66 24.04 MAX 27.75 27.86 24.31
* The unpatched 3.9-rc2 scheduler gives inconsistent performance as tasks may randomly be placed on either A7 or A15 cores. The max/min values reflects this behaviour. A15 and A7 performance are ~16.5 and ~33.5 respectively.
' While Alex Shi's patches appear to solve the performance inconsistency for sysbench_1t, it is not the true picture for all workloads. This can be seen for sysbench_2t.
To ensure that the proposed changes does not affect normal SMP systems, the same benchmarks have been run on a 2xCortex-A15 configuration as well:
SMP: Average times over 20 runs normalized to 3.9-rc2 (lower is better): 3.9-rc2 +shi +shi+patches Improvement cyclictest AVG 78.6 75.3 77.6 1.34% MIN 69 69 69 MAX 135 98 125 hackbench AVG 3.55 3.54 3.55 0.06% MIN 3.51 3.48 3.49 MAX 3.66 3.65 3.67 sysbench_1t AVG 16.48 16.48 16.48 -0.03% MIN 16.47 16.48 16.48 MAX 16.49 16.48 16.48 sysbench_2t AVG 16.53 16.53 16.54 -0.05% MIN 16.47 16.47 16.48 MAX 16.59 16.57 16.59 sysbench_5t AVG 41.16 41.15 41.15 0.04% MIN 41.14 41.13 41.11 MAX 41.35 41.19 41.17 ---
Peter, Would you like to consider pick up the patchset? or give some comments? :)
Best regards Alex
[PATCH v4 1/6] Revert "sched: Introduce temporary FAIR_GROUP_SCHED [PATCH v4 2/6] sched: set initial value of runnable avg for new [PATCH v4 3/6] sched: update cpu load after task_tick. [PATCH v4 4/6] sched: compute runnable load avg in cpu_load and [PATCH v4 5/6] sched: consider runnable load average in move_tasks [PATCH v4 6/6] sched: consider runnable load average in
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