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SubjectRe: [RFC] NUMA schedulers benchmark results
Errm, your magic shellscript is too wierd (aka doesn't work).
Can you just send the files out as attatchments?

M.

--On Sunday, October 06, 2002 10:24 PM +0200 Erich Focht <efocht@ess.nec.de> wrote:

> Hi,
>
> here comes the benchmark I used for the NUMA scheduler test. Would
> be interesting to know whether it is useful to any other NUMA
> developer...
>
> Regards,
> Erich
>
> PS: it uses a 'time' command that understands the --format option,
> e.g. GNU time 1.7. Change it in the main script, if it doesn't
> work for you.
>
>
> On Sunday 06 October 2002 18:51, Erich Focht wrote:
>> Hi,
>>
>> here are some results from testing various versions and approaches
>> to a NUMA scheduler. I used the numa_test benchmark which I'll post
>> in a separate email. It runs in parallel N tasks doing the same job:
>> access randomly a large array. As the array is large enough not to
>> fit into cache, this is very memory latency sensitive. Also it is
>> memory bandwidth sensitive. To emulate a real multi-user environment, the
>> jobs are disturbed by a short load peak. This is simulated by a call
>> to "hackbench" 3 seconds after the tasks were started. The performance
>> of the user tasks is depending very much on where they are scheduled
>> and are CPU hoggers such that the user times are quite independent of
>> the non-scheduler part of the underlying kernel. The elapsed times
>> are depending on "hackbench" which actually blocks the machine for the
>> time it is running. Hackbench is depending on the underlying kernel
>> and one should compare "elapsed_time - hackbench_time".
>>
>> The test machine is a 16 CPU NEC Azusa with Itanium processors and
>> four nodes. The tested schedulers are:
>>
>> A: O(1) scheduler in 2.5.39
>> B: O(1) scheduler with task steal limited to only one task (node
>> affine scheduler with CONFIG_NUMA_SCHED=n) under 2.4.18
>> C: Michael Hohnbaum's "simple NUMA scheduler" under 2.5.39
>> D: pooling NUMA scheduler, no initial load balancing, idle pool_delay
>> set to 0, under 2.4.18
>> E: node affine scheduler with initial load balancing and static homenode
>> F: node affine scheduler without initial load balancing and dynamic
>> homenode selection (homenode selected where most of the memory is
>> allocated).
>>
>> As I'm rewriting the node affine scheduler to be more modular, I'll
>> redo the tests for cases D, E, F on top of 2.5.X kernels soon.
>>
>> The results are summarized in the tables below. A set of outputs (for
>> N=8, 16, 32) is attached. They show clearly why the node affine
>> scheduler beats them all: The initial load balancing is node-aware,
>> the task-stealing too. Sometimes the node affine force is not large
>> enough to bring the task back to the homenode, but it is almost always
>> good enough.
>>
>> The (F) solution with dynamically determined homenode show that the
>> initial load balancing is crucial, as the equal node balance is not
>> strongly enforced dynamically. So the optimal solution is probably
>> (F) with initial load balancing.
>>
>>
>> Average user time (U) and total user time (TU). Minimum per row should
>> be considered.
>> ----------------------------------------------------------------------
>> Scheduler: A B C D E F
>> N=4 U 28.12 30.77 33.00 - 27.20 30.29
>> TU 112.55 123.13 132.08 - 108.88 121.25
>> N=8 U 30.47 31.39 31.65 30.76 28.67 30.08
>> TU 243.86 251.27 253.30 246.23 229.51 240.75
>> N=16 U 36.42 33.64 32.18 32.27 31.50 32.83
>> TU 582.91 538.49 515.11 516.53 504.17 525.59
>> N=32 U 38.69 34.83 34.05 33.76 33.89 34.11
>> TU 1238.4 1114.9 1090.1 1080.8 1084.9 1091.9
>> N=64 U 39.73 34.73 34.23 - (33.32) 34.98
>> TU 2543.4 2223.4 2191.7 - (2133) 2239.5
>>
>>
>> Elapsed time (E), hackbench time (H). Diferences between 2.4.18 and
>> 2.5.39 based kernels due to "hackbench", which performs differently.
>> Compare E-H within a row, but don't take it too seriously.
>> --------------------------------------------------------------------
>> Scheduler: A B C D E F
>> N=4 E 37.33 37.96 48.31 - 28.14 35.91
>> H 9.98 1.49 10.65 - 1.99 1.43
>> N=8 E 46.17 39.50 42.53 39.72 30.28 38.28
>> H 9.64 1.86 7.27 2.07 2.33 1.86
>> N=16 E 47.21 44.67 49.66 42.97 36.98 42.51
>> H 5.90 4.69 2.93 5.178 5.56 5.94
>> N=32 E 88.60 79.92 80.34 78.35 76.84 77.38
>> H 6.29 5.23 2.85 4.51 5.29 4.28
>> N=64 E 167.10 147.16 150.59 - (133.9) 148.94
>> H 5.96 4.67 3.10 - (-) 6.86
>>
>> (The E:N=64 results are without hackbench disturbance.)
>>
>> Best regards,
>> Erich


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