tree 52f02b96949b59167c1ae8fdf68d6336b7fe9920
parent d48f66724a212f26105dcc1d2dfa3aad40ccb681
author Tim Lee <timlee660101@gmail.com> 1680836834 +0800
committer Tim Lee <timlee660101@gmail.com> 1680836834 +0800

meta-nuvoton: linux: npcm8xx: remove CONFIG_PREEMPT

We’ve run various benchmark test tools between with and w/o this
configuration. This is a tradeoff for latency and throughput.
However, according our test results, w/o this configuration that
can get more benefit for our system. Thus, we need to remove it.

1. From systemd-analyze test result:
w/o CONFIG_PREEMPT that can save system startup finish time around 26s.
And all services loading time got improved obviously when booting up.
w/o test case:
Startup finished in 4.208s (kernel) + 31.126s (userspace) = 35.335s
multi-user.target reached after 24.453s in userspace.
13.620s phosphor-pid-control.service
13.252s xyz.openbmc_project.Software.BMC.Updater.service
10.936s xyz.openbmc_project.User.Manager.service
10.104s xyz.openbmc_project.Chassis.Control.Power@0.service
 9.396s xyz.openbmc_project.LED.GroupManager.service
 9.360s xyz.openbmc_project.Network.service
 9.309s xyz.openbmc_project.State.BMC.service
 8.603s xyz.openbmc_project.Settings.service
 8.357s xyz.openbmc_project.Dump.Manager.service
 8.210s xyz.openbmc_project.Logging.service
 8.018s xyz.openbmc_project.Software.Download.service
 7.967s xyz.openbmc_project.Syslog.Config.service
 7.912s xyz.openbmc_project.EntityManager.service

with test case:
Startup finished in 4.385s (kernel) + 56.799s (userspace) = 1min 1.184s
multi-user.target reached after 49.875s in userspace.
36.118s xyz.openbmc_project.Software.BMC.Updater.service
32.475s xyz.openbmc_project.Chassis.Control.Power@0.service
32.347s xyz.openbmc_project.EntityManager.service
31.571s xyz.openbmc_project.User.Manager.service
29.570s xyz.openbmc_project.Network.service
27.591s xyz.openbmc_project.LED.GroupManager.service
26.401s xyz.openbmc_project.State.BMC.service
22.871s xyz.openbmc_project.Logging.service
22.712s xyz.openbmc_project.Syslog.Config.service
21.975s nslcd.service
21.896s xyz.openbmc_project.Dump.Manager.service
21.121s xyz.openbmc_project.ObjectMapper.service
20.942s avahi-daemon.service

2. From system-bootchart test result: (more detail in bootchart.svg)
w/o CONFIG_PREEMPT that can save IO utilization finish time around 26s.
w/o test case: Idle time: 21.789s
with test case: Idle time: 47.155s

3. From sysbench test result:
w/o CONFIG_PREEMPT that throughput got improved and latency doesn’t
increase obviously.
w/o test case:
File operations:
    reads/s:                      443.34
    writes/s:                     297.11
    fsyncs/s:                     1139.77

Throughput:
    read, MiB/s:                  6.93
    written, MiB/s:               4.64

Latency (ms):
    min:                          0.00
    avg:                          9.48
    max:                          306.51
    95th percentile:              65.65
    sum:                          160735.37

with test case:
File operations:
    reads/s:                      398.14
    writes/s:                     266.95
    fsyncs/s:                     1046.28

Throughput:
    read, MiB/s:                  6.22
    written, MiB/s:               4.17

Latency (ms):
    min:                          0.00
    avg:                          10.58
    max:                          321.21
    95th percentile:              73.13
    sum:                          159964.46

4. From fio test result:
w/o CONFIG_PREEMPT that latency doesn’t increase obviously also.
w/o test case:
[read] 512 4K 8K 16K 64K 128K 256K 512K
[lat] 8.74 67.91 135.66 270.93 1076.28 2133.23 4198.83 8111.18 (ms)
[randread] 512 4K 8K 16K 64K 128K 256K 512K
[lat] 8.99 68.14 135.83 270.90 1075.77 2131.96 4194.33 8099.78 (ms)

with test case:
[read] 512 4K 8K 16K 64K 128K 256K 512K
[lat] 8.90 68.18 136.14 272.06 1079.31 2142.20 4207.71 7952.04 (ms)
[randread] 512 4K 8K 16K 64K 128K 256K 512K
[lat] 9.33 68.70 136.41 272.31 1080.27 2141.74 4208.37 8070.45 (ms)

Signed-off-by: Tim Lee <timlee660101@gmail.com>
Change-Id: I39f2c1ecc2c4d713b5fce7629cb95d8408526b52