From: shrikanth suresh hegde <sshegde@linux.vnet.ibm.com>
To: Vincent Guittot <vincent.guittot@linaro.org>
Subject: Re: [PATCH v7 0/9] Add latency priority for CFS class
Date: Sun, 13 Nov 2022 13:26:20 +0530 [thread overview]
Message-ID: <34112324-de67-55eb-92bc-181a98c4311c@linux.vnet.ibm.com> (raw)
In-Reply-To: <20221028093403.6673-1-vincent.guittot@linaro.org>
> This patchset restarts the work about adding a latency priority to describe
> the latency tolerance of cfs tasks.
>
>
Hi Vincent.
Tested the patches on the power10 machine. It is 80 core system with SMT=8. i.e
total of 640 cpus. on the large workload which mainly interacts with the
database there is minor improvement of 3-5%.
the method followed is creating a cgroup, assigning a latency nice value of -20,
-10, 0 and adding the tasks to procs of the cgroup. outside of cgroup, stress-ng
load is running and it is not set any latency value. stress-ng --cpu=768 -l 50
with microbenchmarks, hackbench the values are more or less the same. for large
process pool of 60, there is 10% improvement. schbench tail latencies show
significant improvement with low and medium load upto 256 groups. only 512
groups shows a slight decline.
Hackbench (Iterations or N=50)
Process 6.1_Base 6.1_Latency_Nice
10 0.13 0.14
20 0.18 0.18
30 0.24 0.25
40 0.34 0.33
50 0.40 0.41
60 0.53 0.49
schbench (Iterations or N=5)
Groups: 1
6.1_Base 6.1_Latency_Nice
50.0th: 10.8 9.8
75.0th: 12.4 11.4
90.0th: 14.2 13.2
95.0th: 15.6 14.6
99.0th: 27.8 19.0
99.5th: 38.0 21.6
99.9th: 66.2 25.4
Groups: 2
6.1_Base 6.1_Latency_Nice
50.0th: 11.2 10.8
75.0th: 13.2 12.4
90.0th: 15.0 15.0
95.0th: 16.6 16.6
99.0th: 22.4 22.8
99.5th: 23.8 27.8
99.9th: 30.2 45.6
Groups: 4
6.1_Base 6.1_Latency_Nice
50.0th: 13.8 11.2
75.0th: 16.0 13.2
90.0th: 18.6 15.2
95.0th: 20.4 16.6
99.0th: 28.8 21.6
99.5th: 48.8 25.2
99.9th: 900.2 47.0
Groups: 8
6.1_Base 6.1_Latency_Nice
50.0th: 17.8 14.4
75.0th: 21.8 17.2
90.0th: 25.4 20.4
95.0th: 28.0 22.4
99.0th: 52.8 28.4
99.5th: 156.4 32.6
99.9th: 1990.2 52.0
Groups: 16
6.1_Base 6.1_Latency_Nice
50.0th: 26.0 21.0
75.0th: 33.0 27.8
90.0th: 39.6 34.4
95.0th: 43.4 38.6
99.0th: 66.8 48.8
99.5th: 170.6 60.6
99.9th: 3308.8 201.6
Groups: 32
6.1_Base 6.1_Latency_Nice
50.0th: 40.8 38.6
75.0th: 55.4 52.8
90.0th: 67.0 64.2
95.0th: 74.2 71.6
99.0th: 106.0 90.0
99.5th: 323.8 133.0
99.9th: 4789.6 459.2
Groups: 64
6.1_Base 6.1_Latency_Nice
50.0th: 72.6 68.2
75.0th: 103.4 97.8
90.0th: 127.6 120.0
95.0th: 141.2 132.0
99.0th: 343.4 158.4
99.5th: 1609.0 180.8
99.9th: 6571.2 686.6
Groups: 128
6.1_Base 6.1_Latency_Nice
50.0th: 147.2 147.2
75.0th: 216.4 217.2
90.0th: 268.4 268.2
95.0th: 300.6 294.8
99.0th: 3500.0 638.6
99.5th: 5995.2 2522.8
99.9th: 10390.4 9451.2
Groups: 256
6.1_Base 6.1_Latency_Nice
50.0th: 340.8 333.2
75.0th: 551.8 530.2
90.0th: 3528.4 1919.2
95.0th: 7312.8 5558.4
99.0th: 14630.4 12912.0
99.5th: 17955.2 14950.4
99.9th: 23059.2 20230.4
Groups: 512
6.1_Base 6.1_Latency_Nice
50.0th: 1021.8 990.6
75.0th: 9545.6 10044.8
90.0th: 20972.8 21638.4
95.0th: 29971.2 30291.2
99.0th: 42355.2 46707.2
99.5th: 48550.4 52057.6
99.9th: 58867.2 60147.2
Tested-by: shrikanth Hegde <sshegde@linux.vnet.ibm.com>
next prev parent reply other threads:[~2022-11-13 8:51 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-28 9:33 [PATCH v7 0/9] Add latency priority for CFS class Vincent Guittot
2022-10-28 9:33 ` [PATCH v7 1/9] sched/fair: fix unfairness at wakeup Vincent Guittot
2022-11-05 14:32 ` Chen Yu
2022-11-07 8:00 ` Vincent Guittot
2022-10-28 9:33 ` [PATCH v7 2/9] sched: Introduce latency-nice as a per-task attribute Vincent Guittot
2022-10-28 9:33 ` [PATCH v7 3/9] sched/core: Propagate parent task's latency requirements to the child task Vincent Guittot
2022-10-28 9:33 ` [PATCH v7 4/9] sched: Allow sched_{get,set}attr to change latency_nice of the task Vincent Guittot
2022-10-28 9:33 ` [PATCH v7 5/9] sched/fair: Take into account latency priority at wakeup Vincent Guittot
2022-11-13 8:02 ` shrikanth suresh hegde
2022-11-13 8:39 ` shrikanth suresh hegde
2022-11-14 10:36 ` Vincent Guittot
2022-10-28 9:34 ` [PATCH v7 6/9] sched/fair: Add sched group latency support Vincent Guittot
2022-11-01 19:28 ` Qais Yousef
2022-11-03 8:46 ` Vincent Guittot
2022-11-03 14:27 ` Qais Yousef
2022-11-03 17:02 ` Vincent Guittot
2022-11-04 10:14 ` Joel Fernandes
2022-11-04 10:37 ` Vincent Guittot
2022-11-04 10:48 ` Joel Fernandes
2022-11-04 10:57 ` Vincent Guittot
2022-11-04 10:55 ` Joel Fernandes
2022-11-04 12:06 ` Qais Yousef
2022-11-04 11:47 ` Qais Yousef
2022-11-04 11:21 ` Qais Yousef
2022-11-04 13:13 ` Joel Fernandes
2022-11-05 14:28 ` Qais Yousef
2022-11-04 14:24 ` Vincent Guittot
2022-11-04 14:57 ` Joel Fernandes
2022-11-04 15:03 ` Vincent Guittot
2022-11-04 15:12 ` Joel Fernandes
2022-11-04 15:23 ` Vincent Guittot
2022-11-05 13:41 ` Qais Yousef
2022-10-28 9:34 ` [PATCH v7 7/9] sched/core: Support latency priority with sched core Vincent Guittot
2022-10-28 9:34 ` [PATCH v7 8/9] sched/fair: Add latency list Vincent Guittot
2022-10-28 9:34 ` [PATCH v7 9/9] sched/fair: remove check_preempt_from_others Vincent Guittot
2022-11-13 7:56 ` shrikanth suresh hegde [this message]
2022-11-13 8:34 ` [PATCH v7 0/9] Add latency priority for CFS class shrikanth suresh hegde
2022-11-14 10:40 ` Vincent Guittot
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