linux/kernel/sched
Barry Song 778c558f49 sched: Add cluster scheduler level in core and related Kconfig for ARM64
This patch adds scheduler level for clusters and automatically enables
the load balance among clusters. It will directly benefit a lot of
workload which loves more resources such as memory bandwidth, caches.

Testing has widely been done in two different hardware configurations of
Kunpeng920:

 24 cores in one NUMA(6 clusters in each NUMA node);
 32 cores in one NUMA(8 clusters in each NUMA node)

Workload is running on either one NUMA node or four NUMA nodes, thus,
this can estimate the effect of cluster spreading w/ and w/o NUMA load
balance.

* Stream benchmark:

4threads stream (on 1NUMA * 24cores = 24cores)
                stream                 stream
                w/o patch              w/ patch
MB/sec copy     29929.64 (   0.00%)    32932.68 (  10.03%)
MB/sec scale    29861.10 (   0.00%)    32710.58 (   9.54%)
MB/sec add      27034.42 (   0.00%)    32400.68 (  19.85%)
MB/sec triad    27225.26 (   0.00%)    31965.36 (  17.41%)

6threads stream (on 1NUMA * 24cores = 24cores)
                stream                 stream
                w/o patch              w/ patch
MB/sec copy     40330.24 (   0.00%)    42377.68 (   5.08%)
MB/sec scale    40196.42 (   0.00%)    42197.90 (   4.98%)
MB/sec add      37427.00 (   0.00%)    41960.78 (  12.11%)
MB/sec triad    37841.36 (   0.00%)    42513.64 (  12.35%)

12threads stream (on 1NUMA * 24cores = 24cores)
                stream                 stream
                w/o patch              w/ patch
MB/sec copy     52639.82 (   0.00%)    53818.04 (   2.24%)
MB/sec scale    52350.30 (   0.00%)    53253.38 (   1.73%)
MB/sec add      53607.68 (   0.00%)    55198.82 (   2.97%)
MB/sec triad    54776.66 (   0.00%)    56360.40 (   2.89%)

Thus, it could help memory-bound workload especially under medium load.
Similar improvement is also seen in lkp-pbzip2:

* lkp-pbzip2 benchmark

2-96 threads (on 4NUMA * 24cores = 96cores)
                  lkp-pbzip2              lkp-pbzip2
                  w/o patch               w/ patch
Hmean     tput-2   11062841.57 (   0.00%)  11341817.51 *   2.52%*
Hmean     tput-5   26815503.70 (   0.00%)  27412872.65 *   2.23%*
Hmean     tput-8   41873782.21 (   0.00%)  43326212.92 *   3.47%*
Hmean     tput-12  61875980.48 (   0.00%)  64578337.51 *   4.37%*
Hmean     tput-21 105814963.07 (   0.00%) 111381851.01 *   5.26%*
Hmean     tput-30 150349470.98 (   0.00%) 156507070.73 *   4.10%*
Hmean     tput-48 237195937.69 (   0.00%) 242353597.17 *   2.17%*
Hmean     tput-79 360252509.37 (   0.00%) 362635169.23 *   0.66%*
Hmean     tput-96 394571737.90 (   0.00%) 400952978.48 *   1.62%*

2-24 threads (on 1NUMA * 24cores = 24cores)
                 lkp-pbzip2               lkp-pbzip2
                 w/o patch                w/ patch
Hmean     tput-2   11071705.49 (   0.00%)  11296869.10 *   2.03%*
Hmean     tput-4   20782165.19 (   0.00%)  21949232.15 *   5.62%*
Hmean     tput-6   30489565.14 (   0.00%)  33023026.96 *   8.31%*
Hmean     tput-8   40376495.80 (   0.00%)  42779286.27 *   5.95%*
Hmean     tput-12  61264033.85 (   0.00%)  62995632.78 *   2.83%*
Hmean     tput-18  86697139.39 (   0.00%)  86461545.74 (  -0.27%)
Hmean     tput-24 104854637.04 (   0.00%) 104522649.46 *  -0.32%*

In the case of 6 threads and 8 threads, we see the greatest performance
improvement.

Similar improvement can be seen on lkp-pixz though the improvement is
smaller:

* lkp-pixz benchmark

2-24 threads lkp-pixz (on 1NUMA * 24cores = 24cores)
                  lkp-pixz               lkp-pixz
                  w/o patch              w/ patch
Hmean     tput-2   6486981.16 (   0.00%)  6561515.98 *   1.15%*
Hmean     tput-4  11645766.38 (   0.00%) 11614628.43 (  -0.27%)
Hmean     tput-6  15429943.96 (   0.00%) 15957350.76 *   3.42%*
Hmean     tput-8  19974087.63 (   0.00%) 20413746.98 *   2.20%*
Hmean     tput-12 28172068.18 (   0.00%) 28751997.06 *   2.06%*
Hmean     tput-18 39413409.54 (   0.00%) 39896830.55 *   1.23%*
Hmean     tput-24 49101815.85 (   0.00%) 49418141.47 *   0.64%*

* SPECrate benchmark

4,8,16 copies mcf_r(on 1NUMA * 32cores = 32cores)
		Base     	 	Base
		Run Time   	 	Rate
		-------  	 	---------
4 Copies	w/o 580 (w/ 570)       	w/o 11.1 (w/ 11.3)
8 Copies	w/o 647 (w/ 605)       	w/o 20.0 (w/ 21.4, +7%)
16 Copies	w/o 844 (w/ 844)       	w/o 30.6 (w/ 30.6)

32 Copies(on 4NUMA * 32 cores = 128cores)
[w/o patch]
                 Base     Base        Base
Benchmarks       Copies  Run Time     Rate
--------------- -------  ---------  ---------
500.perlbench_r      32        584       87.2  *
502.gcc_r            32        503       90.2  *
505.mcf_r            32        745       69.4  *
520.omnetpp_r        32       1031       40.7  *
523.xalancbmk_r      32        597       56.6  *
525.x264_r            1         --            CE
531.deepsjeng_r      32        336      109    *
541.leela_r          32        556       95.4  *
548.exchange2_r      32        513      163    *
557.xz_r             32        530       65.2  *
 Est. SPECrate2017_int_base              80.3

[w/ patch]
                  Base     Base        Base
Benchmarks       Copies  Run Time     Rate
--------------- -------  ---------  ---------
500.perlbench_r      32        580      87.8 (+0.688%)  *
502.gcc_r            32        477      95.1 (+5.432%)  *
505.mcf_r            32        644      80.3 (+13.574%) *
520.omnetpp_r        32        942      44.6 (+9.58%)   *
523.xalancbmk_r      32        560      60.4 (+6.714%%) *
525.x264_r            1         --           CE
531.deepsjeng_r      32        337      109  (+0.000%) *
541.leela_r          32        554      95.6 (+0.210%) *
548.exchange2_r      32        515      163  (+0.000%) *
557.xz_r             32        524      66.0 (+1.227%) *
 Est. SPECrate2017_int_base              83.7 (+4.062%)

On the other hand, it is slightly helpful to CPU-bound tasks like
kernbench:

* 24-96 threads kernbench (on 4NUMA * 24cores = 96cores)
                     kernbench              kernbench
                     w/o cluster            w/ cluster
Min       user-24    12054.67 (   0.00%)    12024.19 (   0.25%)
Min       syst-24     1751.51 (   0.00%)     1731.68 (   1.13%)
Min       elsp-24      600.46 (   0.00%)      598.64 (   0.30%)
Min       user-48    12361.93 (   0.00%)    12315.32 (   0.38%)
Min       syst-48     1917.66 (   0.00%)     1892.73 (   1.30%)
Min       elsp-48      333.96 (   0.00%)      332.57 (   0.42%)
Min       user-96    12922.40 (   0.00%)    12921.17 (   0.01%)
Min       syst-96     2143.94 (   0.00%)     2110.39 (   1.56%)
Min       elsp-96      211.22 (   0.00%)      210.47 (   0.36%)
Amean     user-24    12063.99 (   0.00%)    12030.78 *   0.28%*
Amean     syst-24     1755.20 (   0.00%)     1735.53 *   1.12%*
Amean     elsp-24      601.60 (   0.00%)      600.19 (   0.23%)
Amean     user-48    12362.62 (   0.00%)    12315.56 *   0.38%*
Amean     syst-48     1921.59 (   0.00%)     1894.95 *   1.39%*
Amean     elsp-48      334.10 (   0.00%)      332.82 *   0.38%*
Amean     user-96    12925.27 (   0.00%)    12922.63 (   0.02%)
Amean     syst-96     2146.66 (   0.00%)     2122.20 *   1.14%*
Amean     elsp-96      211.96 (   0.00%)      211.79 (   0.08%)

Note this patch isn't an universal win, it might hurt those workload
which can benefit from packing. Though tasks which want to take
advantages of lower communication latency of one cluster won't
necessarily been packed in one cluster while kernel is not aware of
clusters, they have some chance to be randomly packed. But this
patch will make them more likely spread.

Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Tested-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2021-10-15 11:25:16 +02:00
..
autogroup.c
autogroup.h
clock.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
completion.c completion: Use lockdep_assert_RT_in_threaded_ctx() in complete_all() 2020-03-23 18:40:25 +01:00
core_sched.c sched: Make cookie functions static 2021-10-05 15:52:07 +02:00
core.c sched: Add wrapper for get_wchan() to keep task blocked 2021-10-15 11:25:14 +02:00
cpuacct.c sched: Wrap rq::lock access 2021-05-12 11:43:26 +02:00
cpudeadline.c sched,rt: Use the full cpumask for balancing 2020-11-10 18:39:00 +01:00
cpudeadline.h
cpufreq_schedutil.c cpufreq: schedutil: Use kobject release() method to free sugov_tunables 2021-08-06 15:34:55 +02:00
cpufreq.c cpufreq: Avoid leaving stale IRQ work items during CPU offline 2019-12-12 17:59:43 +01:00
cpupri.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
cpupri.h sched/cpupri: Add CPUPRI_HIGHER 2020-10-29 11:00:30 +01:00
cputime.c Scheduler updates for this cycle are: 2021-04-28 13:33:57 -07:00
deadline.c sched/dl: Support schedstats for deadline sched class 2021-10-05 15:51:53 +02:00
debug.c sched: Fix DEBUG && !SCHEDSTATS warn 2021-10-06 10:30:57 +02:00
fair.c sched/numa: Fix a few comments 2021-10-14 13:09:58 +02:00
features.h sched: Disable TTWU_QUEUE on RT 2021-10-05 15:52:12 +02:00
idle.c sched/idle: Make the idle timer expire in hard interrupt context 2021-09-09 10:36:16 +02:00
isolation.c sched/isolation: Reconcile rcu_nocbs= and nohz_full= 2021-05-13 14:12:47 +02:00
loadavg.c sched: Make multiple runqueue task counters 32-bit 2021-05-12 21:34:17 +02:00
Makefile sched: Disable -Wunused-but-set-variable 2021-10-15 11:25:15 +02:00
membarrier.c sched/membarrier: fix missing local execution of ipi_sync_rq_state() 2021-03-06 12:40:21 +01:00
pelt.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
pelt.h Merge branch 'sched/urgent' into sched/core, to resolve conflicts 2021-06-18 11:31:25 +02:00
psi.c Merge branch 'for-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2021-07-01 17:22:14 -07:00
rt.c sched/rt: Support schedstats for RT sched class 2021-10-05 15:51:51 +02:00
sched-pelt.h
sched.h sched: Make cookie functions static 2021-10-05 15:52:07 +02:00
smp.h sched/headers: Split out open-coded prototypes into kernel/sched/smp.h 2020-05-28 11:03:20 +02:00
stats.c sched: Introduce task block time in schedstats 2021-10-05 15:51:48 +02:00
stats.h sched: Make schedstats helpers independent of fair sched class 2021-10-05 15:51:47 +02:00
stop_task.c sched: Make struct sched_statistics independent of fair sched class 2021-10-05 15:51:45 +02:00
swait.c sched/swait: Prepare usage in completions 2020-03-21 16:00:23 +01:00
topology.c sched: Add cluster scheduler level in core and related Kconfig for ARM64 2021-10-15 11:25:16 +02:00
wait_bit.c sched/wait: fix ___wait_var_event(exclusive) 2019-12-17 13:32:50 +01:00
wait.c rq-qos: fix missed wake-ups in rq_qos_throttle try two 2021-06-08 15:12:57 -06:00