Test case 1, without NO_HZ_FULL built-in (default ubuntu kernel config):
Run test program 4 times without taskset
tail -n 2 log/notaskset.*
==> log/notaskset.1 <==
total 49116169085 nsec
avg 491 nsec
==> log/notaskset.2 <==
total 47852147979 nsec
avg 478 nsec
==> log/notaskset.3 <==
total 49077846508 nsec
avg 490 nsec
==> log/notaskset.4 <==
total 49037126328 nsec
avg 490 nsec
Run test program 4 times with taskset to CPU 4
tail -n 2 log/taskset.*
==> log/taskset.1 <==
total 48534105655 nsec
avg 485 nsec
==> log/taskset.2 <==
total 48220818730 nsec
avg 482 nsec
==> log/taskset.3 <==
total 48496349690 nsec
avg 484 nsec
==> log/taskset.4 <==
total 48224935123 nsec
avg 482 nsec
Test case 2, with NO_HZ_FULL built-in but not activate in kernel cmdline:
Run test program 4 times without taskset
tail -n 2 nohz-log/notaskset.*
==> nohz-log/notaskset.1 <==
total 48533643569 nsec
avg 485 nsec
==> nohz-log/notaskset.2 <==
total 47933581377 nsec
avg 479 nsec
==> nohz-log/notaskset.3 <==
total 49396311930 nsec
avg 493 nsec
==> nohz-log/notaskset.4 <==
total 48812288206 nsec
avg 488 nsec
Run test program 4 times with taskset to CPU 4
tail -n 2 nohz-log/taskset.*
==> nohz-log/taskset.1 <==
total 48929140711 nsec
avg 489 nsec
==> nohz-log/taskset.2 <==
total 48231661796 nsec
avg 482 nsec
==> nohz-log/taskset.3 <==
total 48482539803 nsec
avg 484 nsec
==> nohz-log/taskset.4 <==
total 48272541984 nsec
avg 482 nsec
Test case 3, with NO_HZ_FULL built-in, activate nohz_full in kernel cmdline:
cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-5.15.0-86-generic root=UUID=69036292-bdc0-4904-8724-974723f1095a ro isolcpus=2-19,22-39 nohz_full=2-19,22-39 rcu_nocbs=2-19,22-39
Run test program 4 times without taskset
tail -n 2 nohz-activate-log/notaskset.*
==> nohz-activate-log/notaskset.1 <==
total 52088354594 nsec
avg 520 nsec
==> nohz-activate-log/notaskset.2 <==
total 49226221648 nsec
avg 492 nsec
==> nohz-activate-log/notaskset.3 <==
total 51462517639 nsec
avg 514 nsec
==> nohz-activate-log/notaskset.4 <==
total 51516303613 nsec
avg 515 nsec
Run test program 4 times with taskset to CPU 4
tail -n 2 nohz-activate-log/taskset.*
==> nohz-activate-log/taskset.1 <==
total 56753345940 nsec
avg 567 nsec
==> nohz-activate-log/taskset.2 <==
total 55720022538 nsec
avg 557 nsec
==> nohz-activate-log/taskset.3 <==
total 55701214354 nsec
avg 557 nsec
==> nohz-activate-log/taskset.4 <==
total 55740784595 nsec
avg 557 nsec
Test case 4, with NO_HZ_FULL built-in, activate nohz_full in kernel cmdline, but run on non-activate CPU:
Run test program on non-activate nohz_full CPU 20
tail -n 2 nohz-activate-off-log/*
==> nohz-activate-off-log/taskset.1 <==
total 49686932587 nsec
avg 496 nsec
==> nohz-activate-off-log/taskset.2 <==
total 49141560622 nsec
avg 491 nsec
==> nohz-activate-off-log/taskset.3 <==
total 49072045557 nsec
avg 490 nsec
==> nohz-activate-off-log/taskset.4 <==
total 49071430182 nsec
avg 490 nsec
Results on Intel machine
Hardware configs:
Dell PowerEdge R730xd
Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz
40 CPUs
188G RAM, numa nodes: 2
Software configs: 86.96~20. 04.1) 86.96~20. 04.1+test202310 13b0) /launchpad. net/~gerald- yang-tw/ +archive/ ubuntu/ focal-no- hz-full
OS: ubuntu 20.04
Official kernel: 5.15 hwe (5.15.0-
Test kernel: 5.15 hwe (5.15.0-
https:/
Test case 1, without NO_HZ_FULL built-in (default ubuntu kernel config):
Run test program 4 times without taskset
tail -n 2 log/notaskset.*
==> log/notaskset.1 <==
total 49116169085 nsec
avg 491 nsec
==> log/notaskset.2 <==
total 47852147979 nsec
avg 478 nsec
==> log/notaskset.3 <==
total 49077846508 nsec
avg 490 nsec
==> log/notaskset.4 <==
total 49037126328 nsec
avg 490 nsec
Run test program 4 times with taskset to CPU 4
tail -n 2 log/taskset.*
==> log/taskset.1 <==
total 48534105655 nsec
avg 485 nsec
==> log/taskset.2 <==
total 48220818730 nsec
avg 482 nsec
==> log/taskset.3 <==
total 48496349690 nsec
avg 484 nsec
==> log/taskset.4 <==
total 48224935123 nsec
avg 482 nsec
Test case 2, with NO_HZ_FULL built-in but not activate in kernel cmdline: notaskset. * notaskset. 1 <==
Run test program 4 times without taskset
tail -n 2 nohz-log/
==> nohz-log/
total 48533643569 nsec
avg 485 nsec
==> nohz-log/ notaskset. 2 <==
total 47933581377 nsec
avg 479 nsec
==> nohz-log/ notaskset. 3 <==
total 49396311930 nsec
avg 493 nsec
==> nohz-log/ notaskset. 4 <==
total 48812288206 nsec
avg 488 nsec
Run test program 4 times with taskset to CPU 4
tail -n 2 nohz-log/taskset.*
==> nohz-log/taskset.1 <==
total 48929140711 nsec
avg 489 nsec
==> nohz-log/taskset.2 <==
total 48231661796 nsec
avg 482 nsec
==> nohz-log/taskset.3 <==
total 48482539803 nsec
avg 484 nsec
==> nohz-log/taskset.4 <==
total 48272541984 nsec
avg 482 nsec
Test case 3, with NO_HZ_FULL built-in, activate nohz_full in kernel cmdline: /boot/vmlinuz- 5.15.0- 86-generic root=UUID= 69036292- bdc0-4904- 8724-974723f109 5a ro isolcpus=2-19,22-39 nohz_full= 2-19,22- 39 rcu_nocbs= 2-19,22- 39
cat /proc/cmdline
BOOT_IMAGE=
Run test program 4 times without taskset log/notaskset. * log/notaskset. 1 <==
tail -n 2 nohz-activate-
==> nohz-activate-
total 52088354594 nsec
avg 520 nsec
==> nohz-activate- log/notaskset. 2 <==
total 49226221648 nsec
avg 492 nsec
==> nohz-activate- log/notaskset. 3 <==
total 51462517639 nsec
avg 514 nsec
==> nohz-activate- log/notaskset. 4 <==
total 51516303613 nsec
avg 515 nsec
Run test program 4 times with taskset to CPU 4 log/taskset. * log/taskset. 1 <==
tail -n 2 nohz-activate-
==> nohz-activate-
total 56753345940 nsec
avg 567 nsec
==> nohz-activate- log/taskset. 2 <==
total 55720022538 nsec
avg 557 nsec
==> nohz-activate- log/taskset. 3 <==
total 55701214354 nsec
avg 557 nsec
==> nohz-activate- log/taskset. 4 <==
total 55740784595 nsec
avg 557 nsec
Test case 4, with NO_HZ_FULL built-in, activate nohz_full in kernel cmdline, but run on non-activate CPU: off-log/ * off-log/ taskset. 1 <==
Run test program on non-activate nohz_full CPU 20
tail -n 2 nohz-activate-
==> nohz-activate-
total 49686932587 nsec
avg 496 nsec
==> nohz-activate- off-log/ taskset. 2 <==
total 49141560622 nsec
avg 491 nsec
==> nohz-activate- off-log/ taskset. 3 <==
total 49072045557 nsec
avg 490 nsec
==> nohz-activate- off-log/ taskset. 4 <==
total 49071430182 nsec
avg 490 nsec