[LKP] [sched/core] 9edfbfed3f5: +88.2% hackbench.time.involuntary_context_switches

From: Huang Ying
Date: Mon Feb 09 2015 - 00:58:40 EST


FYI, we noticed the below changes on

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched/core
commit 9edfbfed3f544a7830d99b341f0c175995a02950 ("sched/core: Rework rq->clock update skips")


testbox/testcase/testparams: xps2/hackbench/performance-1600%-process-socket

cebde6d681aa45f9 9edfbfed3f544a7830d99b341f
---------------- --------------------------
%stddev %change %stddev
\ | \
1839273 Â 6% +88.2% 3462337 Â 4% hackbench.time.involuntary_context_switches
41965851 Â 5% +5.6% 44307403 Â 1% hackbench.time.voluntary_context_switches
388 Â 39% -58.6% 160 Â 10% sched_debug.cfs_rq[1]:/.tg_load_contrib
12957 Â 14% -60.5% 5117 Â 11% sched_debug.cfs_rq[2]:/.tg_load_avg
30505 Â 14% -57.7% 12905 Â 6% sched_debug.cfs_rq[3]:/.tg_load_avg
2790 Â 24% -65.4% 964 Â 32% sched_debug.cfs_rq[3]:/.blocked_load_avg
2915 Â 23% -62.2% 1101 Â 29% sched_debug.cfs_rq[3]:/.tg_load_contrib
1839273 Â 6% +88.2% 3462337 Â 4% time.involuntary_context_switches
1474 Â 28% -61.7% 565 Â 43% sched_debug.cfs_rq[2]:/.tg_load_contrib
11830 Â 15% +63.0% 19285 Â 11% sched_debug.cpu#4.sched_goidle
19319 Â 29% +91.1% 36913 Â 7% sched_debug.cpu#3.sched_goidle
5899 Â 31% -35.6% 3801 Â 11% sched_debug.cfs_rq[4]:/.blocked_load_avg
5999 Â 30% -34.5% 3929 Â 11% sched_debug.cfs_rq[4]:/.tg_load_contrib
37884 Â 13% -33.5% 25207 Â 7% sched_debug.cfs_rq[4]:/.tg_load_avg
229547 Â 5% +47.9% 339519 Â 5% cpuidle.C1-NHM.usage
35712 Â 3% +31.7% 47036 Â 9% cpuidle.C3-NHM.usage
5010 Â 9% -29.0% 3556 Â 20% sched_debug.cfs_rq[6]:/.blocked_load_avg
5139 Â 9% -28.2% 3690 Â 19% sched_debug.cfs_rq[6]:/.tg_load_contrib
49568 Â 6% +24.8% 61867 Â 7% sched_debug.cpu#1.sched_goidle
26369 Â 35% -42.0% 15289 Â 29% cpuidle.C6-NHM.usage
18 Â 16% +36.5% 25 Â 7% sched_debug.cpu#4.nr_running
1.41 Â 12% -19.3% 1.14 Â 13% perf-profile.cpu-cycles.sock_wfree.unix_destruct_scm.skb_release_head_state.skb_release_all.consume_skb
25 Â 15% +28.7% 32 Â 9% sched_debug.cpu#3.nr_running
1.63 Â 11% -18.0% 1.34 Â 12% perf-profile.cpu-cycles.unix_destruct_scm.skb_release_head_state.skb_release_all.consume_skb.unix_stream_recvmsg
0.57 Â 8% +9.6% 0.62 Â 5% turbostat.CPU%c1
148 Â 11% -16.7% 123 Â 7% sched_debug.cfs_rq[1]:/.load
109 Â 6% +17.1% 128 Â 6% sched_debug.cpu#6.cpu_load[0]
2.41 Â 8% -13.3% 2.09 Â 11% perf-profile.cpu-cycles.skb_release_head_state.skb_release_all.consume_skb.unix_stream_recvmsg.sock_aio_read
147 Â 12% -16.4% 123 Â 7% sched_debug.cpu#1.load
111 Â 5% +15.4% 129 Â 5% sched_debug.cpu#6.cpu_load[2]
110 Â 5% +14.9% 127 Â 5% sched_debug.cfs_rq[6]:/.runnable_load_avg
112 Â 5% +14.5% 128 Â 4% sched_debug.cpu#6.cpu_load[3]
113 Â 5% +13.2% 128 Â 3% sched_debug.cpu#6.cpu_load[4]
789953 Â 2% -10.8% 704528 Â 4% sched_debug.cpu#3.avg_idle
15471 Â 5% -7.7% 14278 Â 2% sched_debug.cpu#5.curr->pid
2675106 Â 10% +16.2% 3109411 Â 1% sched_debug.cpu#4.nr_switches
2675140 Â 10% +16.2% 3109440 Â 1% sched_debug.cpu#4.sched_count
155201 Â 5% +14.6% 177901 Â 3% softirqs.RCU
8.64 Â 6% -9.6% 7.82 Â 5% perf-profile.cpu-cycles.skb_release_all.consume_skb.unix_stream_recvmsg.sock_aio_read.sock_aio_read
2658351 Â 11% +13.7% 3021564 Â 2% sched_debug.cpu#5.sched_count
2658326 Â 11% +13.7% 3021539 Â 2% sched_debug.cpu#5.nr_switches
71443 Â 5% +9.9% 78486 Â 0% vmstat.system.cs
8209 Â 5% +7.3% 8805 Â 0% vmstat.system.in

xps2: Nehalem
Memory: 4G

To reproduce:

apt-get install ruby ruby-oj
git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git
cd lkp-tests
bin/setup-local job.yaml # the job file attached in this email
bin/run-local job.yaml


Disclaimer:
Results have been estimated based on internal Intel analysis and are provided
for informational purposes only. Any difference in system hardware or software
design or configuration may affect actual performance.


Thanks,
Huang, Ying

tbench_srv &
tbench 4 127.0.0.1
killall tbench_srv
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Attachment: job.yaml
Description: application/yaml