* [LKP] [rcu] 00f5159aeb6: +55.3% will-it-scale.time.involuntary_context_switches
@ 2015-01-21 7:32 Huang Ying
2015-01-21 7:52 ` Paul E. McKenney
0 siblings, 1 reply; 4+ messages in thread
From: Huang Ying @ 2015-01-21 7:32 UTC (permalink / raw)
To: Paul E. McKenney; +Cc: LKML, LKP ML
[-- Attachment #1: Type: text/plain, Size: 8213 bytes --]
FYI, we noticed the below changes on
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git stall.2015.01.06a
commit 00f5159aeb68f08ce29597be86be87d6db0c1ba1 ("rcu: Run grace-period kthreads at real-time priority")
testbox/testcase/testparams: lkp-a03/will-it-scale/performance-lock1
e3663b1024d1f946 00f5159aeb68f08ce29597be86
---------------- --------------------------
%stddev %change %stddev
\ | \
11321 ± 5% +55.3% 17582 ± 14% will-it-scale.time.involuntary_context_switches
28999 ± 44% +109.3% 60700 ± 25% sched_debug.cpu#1.ttwu_count
58384 ± 44% +103.6% 118851 ± 24% sched_debug.cpu#1.nr_switches
26144 ± 48% +90.3% 49762 ± 26% sched_debug.cpu#1.sched_goidle
827 ± 34% -57.3% 353 ± 21% cpuidle.C2-ATM.usage
58976 ± 43% +103.0% 119712 ± 24% sched_debug.cpu#1.sched_count
503 ± 29% -56.5% 219 ± 27% cpuidle.C4-ATM.usage
11321 ± 5% +55.3% 17582 ± 14% time.involuntary_context_switches
156 ± 14% -29.6% 110 ± 19% cpuidle.POLL.usage
50583 ± 2% -21.7% 39630 ± 4% cpuidle.C6-ATM.usage
51597156 ± 2% +23.7% 63848564 ± 3% cpuidle.C1E-ATM.time
39349 ± 2% -12.0% 34622 ± 2% softirqs.SCHED
758790 ± 8% -15.3% 642336 ± 12% sched_debug.cpu#2.sched_count
378981 ± 8% -15.6% 319776 ± 12% sched_debug.cpu#2.ttwu_count
374440 ± 8% -15.5% 316513 ± 12% sched_debug.cpu#2.ttwu_local
5307 ± 0% -1.0% 5255 ± 0% vmstat.system.in
testbox/testcase/testparams: wsm/will-it-scale/performance-open2
e3663b1024d1f946 00f5159aeb68f08ce29597be86
---------------- --------------------------
22128 ± 3% +120.2% 48719 ± 8% will-it-scale.time.involuntary_context_switches
5577 ± 45% +1492.2% 88802 ± 33% sched_debug.cpu#6.sched_count
5457 ± 46% +1526.2% 88751 ± 33% sched_debug.cpu#6.nr_switches
0.45 ± 43% -73.3% 0.12 ± 15% turbostat.%c3
10 ± 24% -55.8% 4 ± 40% sched_debug.cpu#9.nr_uninterruptible
147 ± 11% -58.5% 61 ± 32% sched_debug.cpu#11.load
147 ± 11% -58.5% 61 ± 32% sched_debug.cfs_rq[11]:/.load
10821106 ± 39% -59.8% 4347430 ± 20% cpuidle.C3-NHM.time
356 ± 41% +76.6% 629 ± 3% sched_debug.cfs_rq[6]:/.blocked_load_avg
22128 ± 3% +120.2% 48719 ± 8% time.involuntary_context_switches
145 ± 36% -35.9% 93 ± 30% sched_debug.cpu#5.load
469 ± 29% +55.9% 732 ± 4% sched_debug.cfs_rq[6]:/.tg_load_contrib
145 ± 36% -34.0% 95 ± 29% sched_debug.cfs_rq[5]:/.load
99 ± 8% -27.8% 72 ± 24% sched_debug.cpu#9.load
99 ± 8% -27.8% 72 ± 24% sched_debug.cfs_rq[9]:/.load
219871 ± 6% -33.3% 146545 ± 19% sched_debug.cpu#3.ttwu_local
224610 ± 6% -31.3% 154342 ± 18% sched_debug.cpu#3.sched_goidle
451877 ± 6% -31.1% 311378 ± 18% sched_debug.cpu#3.sched_count
451737 ± 6% -31.1% 311279 ± 18% sched_debug.cpu#3.nr_switches
225208 ± 6% -31.3% 154688 ± 18% sched_debug.cpu#3.ttwu_count
4122 ± 7% -23.6% 3148 ± 17% cpuidle.C3-NHM.usage
84 ± 11% -27.4% 61 ± 5% sched_debug.cpu#7.cpu_load[0]
154565 ± 2% -29.6% 108768 ± 9% cpuidle.C6-NHM.usage
124949 ± 25% +41.4% 176670 ± 15% sched_debug.cpu#2.sched_goidle
74177 ± 2% -23.6% 56653 ± 4% sched_debug.cpu#3.nr_load_updates
79 ± 6% -23.1% 60 ± 5% sched_debug.cpu#7.cpu_load[1]
50107 ± 6% -20.9% 39621 ± 7% sched_debug.cfs_rq[3]:/.exec_clock
76 ± 4% -20.6% 60 ± 6% sched_debug.cpu#7.cpu_load[2]
385983 ± 9% -20.4% 307347 ± 12% sched_debug.cfs_rq[3]:/.min_vruntime
74 ± 2% -18.5% 60 ± 6% sched_debug.cpu#7.cpu_load[3]
1.50 ± 6% -10.0% 1.35 ± 9% perf-profile.cpu-cycles.selinux_file_free_security.security_file_free.__fput.____fput.task_work_run
46086 ± 1% -25.7% 34260 ± 5% softirqs.SCHED
72 ± 1% -15.9% 60 ± 7% sched_debug.cpu#7.cpu_load[4]
74 ± 13% -17.7% 61 ± 2% sched_debug.cfs_rq[7]:/.runnable_load_avg
65 ± 2% +16.9% 76 ± 4% sched_debug.cpu#1.cpu_load[3]
1.94 ± 5% -9.9% 1.74 ± 6% perf-profile.cpu-cycles.security_file_free.__fput.____fput.task_work_run.do_notify_resume
58851 ± 1% +20.5% 70942 ± 9% sched_debug.cfs_rq[1]:/.exec_clock
69880 ± 1% -16.9% 58047 ± 11% sched_debug.cpu#7.nr_load_updates
60 ± 5% +9.5% 66 ± 3% sched_debug.cpu#9.cpu_load[4]
12064 ± 7% +12.4% 13561 ± 5% slabinfo.kmalloc-64.num_objs
67 ± 4% +14.9% 77 ± 4% sched_debug.cpu#1.cpu_load[2]
53070 ± 7% +18.3% 62803 ± 5% sched_debug.cfs_rq[9]:/.exec_clock
64 ± 1% +16.3% 74 ± 4% sched_debug.cpu#1.cpu_load[4]
11895 ± 7% +12.9% 13429 ± 5% slabinfo.kmalloc-64.active_objs
67415 ± 1% -16.4% 56345 ± 11% sched_debug.cfs_rq[7]:/.exec_clock
58403 ± 4% +12.0% 65434 ± 6% sched_debug.cpu#9.nr_load_updates
428535 ± 8% +18.3% 507136 ± 6% sched_debug.cfs_rq[9]:/.min_vruntime
505551 ± 1% +16.3% 588207 ± 8% sched_debug.cfs_rq[1]:/.min_vruntime
1818 ± 5% -8.4% 1665 ± 3% slabinfo.proc_inode_cache.active_objs
1818 ± 5% -8.4% 1665 ± 3% slabinfo.proc_inode_cache.num_objs
616 ± 0% +11.4% 686 ± 4% sched_debug.cfs_rq[1]:/.tg_runnable_contrib
2259 ± 14% +23.5% 2790 ± 5% sched_debug.cpu#3.curr->pid
28336 ± 0% +11.2% 31517 ± 4% sched_debug.cfs_rq[1]:/.avg->runnable_avg_sum
576795 ± 1% -14.6% 492717 ± 10% sched_debug.cfs_rq[7]:/.min_vruntime
7176 ± 0% +2.1% 7323 ± 0% vmstat.system.cs
10798 ± 0% -1.1% 10675 ± 0% vmstat.system.in
lkp-a03: Atom
Memory: 8G
wsm: Westmere
Memory: 6G
will-it-scale.time.involuntary_context_switches
70000 ++------------------------------------------------------------------+
| |
60000 ++ O |
O O O O O O O O O O |
50000 ++ O O O O O O O O
| O O O O O O |
40000 ++ O O O O O |
| |
30000 ++ |
| .*. .*.*.. .* |
20000 *+*..* *..*.* *.*.*..*.*.*. *.*.*..*.*.*..*.*.*..* |
| : : |
10000 ++ : : |
| :: |
0 ++--------------*---------------------------------------------------+
[*] bisect-good sample
[O] bisect-bad sample
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
[-- Attachment #2: job.yaml --]
[-- Type: text/plain, Size: 1582 bytes --]
---
testcase: will-it-scale
default-monitors:
wait: pre-test
uptime:
iostat:
vmstat:
numa-numastat:
numa-vmstat:
numa-meminfo:
proc-vmstat:
proc-stat:
meminfo:
slabinfo:
interrupts:
lock_stat:
latency_stats:
softirqs:
bdi_dev_mapping:
diskstats:
cpuidle:
cpufreq:
turbostat:
sched_debug:
interval: 10
pmeter:
default_watchdogs:
watch-oom:
watchdog:
cpufreq_governor:
- performance
commit: 634b0bd490b7ebd7a054cea4f7e0d25748bde678
model: Westmere
memory: 6G
nr_hdd_partitions: 1
hdd_partitions:
swap_partitions:
rootfs_partition:
netconsole_port: 6667
perf-profile:
freq: 800
will-it-scale:
test:
- open2
testbox: wsm
tbox_group: wsm
kconfig: x86_64-rhel
enqueue_time: 2015-01-16 17:43:47.976990621 +08:00
head_commit: 634b0bd490b7ebd7a054cea4f7e0d25748bde678
base_commit: eaa27f34e91a14cdceed26ed6c6793ec1d186115
branch: next/master
kernel: "/kernel/x86_64-rhel/634b0bd490b7ebd7a054cea4f7e0d25748bde678/vmlinuz-3.19.0-rc4-next-20150116-g634b0bd"
user: lkp
queue: cyclic
rootfs: debian-x86_64-2015-01-13.cgz
result_root: "/result/wsm/will-it-scale/performance-open2/debian-x86_64-2015-01-13.cgz/x86_64-rhel/634b0bd490b7ebd7a054cea4f7e0d25748bde678/0"
job_file: "/lkp/scheduled/wsm/cyclic_will-it-scale-performance-open2-x86_64-rhel-HEAD-634b0bd490b7ebd7a054cea4f7e0d25748bde678-0.yaml"
dequeue_time: 2015-01-16 23:50:07.247065623 +08:00
nr_cpu: "$(nproc)"
job_state: finished
loadavg: 8.12 4.97 2.06 1/146 6693
start_time: '1421423439'
end_time: '1421423743'
version: "/lkp/lkp/.src-20150116-113525"
[-- Attachment #3: reproduce --]
[-- Type: text/plain, Size: 31 bytes --]
./runtest.py open2 32 1 6 9 12
[-- Attachment #4: Type: text/plain, Size: 89 bytes --]
_______________________________________________
LKP mailing list
LKP@linux.intel.com
\r
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [LKP] [rcu] 00f5159aeb6: +55.3% will-it-scale.time.involuntary_context_switches
2015-01-21 7:32 [LKP] [rcu] 00f5159aeb6: +55.3% will-it-scale.time.involuntary_context_switches Huang Ying
@ 2015-01-21 7:52 ` Paul E. McKenney
2015-01-21 8:06 ` Mike Galbraith
0 siblings, 1 reply; 4+ messages in thread
From: Paul E. McKenney @ 2015-01-21 7:52 UTC (permalink / raw)
To: Huang Ying; +Cc: LKML, LKP ML
On Wed, Jan 21, 2015 at 03:32:44PM +0800, Huang Ying wrote:
> FYI, we noticed the below changes on
>
> git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git stall.2015.01.06a
> commit 00f5159aeb68f08ce29597be86be87d6db0c1ba1 ("rcu: Run grace-period kthreads at real-time priority")
Glad this helps!
However, the version that I am pushing during the upcoming merge window
requires a boot parameter rcutree.kthread_prio= set to a value in the
range 1..99 to have effect. The reason is that we need to focus any
risks from this change on the people needing it.
Thanx, Paul
> testbox/testcase/testparams: lkp-a03/will-it-scale/performance-lock1
>
> e3663b1024d1f946 00f5159aeb68f08ce29597be86
> ---------------- --------------------------
> %stddev %change %stddev
> \ | \
> 11321 ± 5% +55.3% 17582 ± 14% will-it-scale.time.involuntary_context_switches
> 28999 ± 44% +109.3% 60700 ± 25% sched_debug.cpu#1.ttwu_count
> 58384 ± 44% +103.6% 118851 ± 24% sched_debug.cpu#1.nr_switches
> 26144 ± 48% +90.3% 49762 ± 26% sched_debug.cpu#1.sched_goidle
> 827 ± 34% -57.3% 353 ± 21% cpuidle.C2-ATM.usage
> 58976 ± 43% +103.0% 119712 ± 24% sched_debug.cpu#1.sched_count
> 503 ± 29% -56.5% 219 ± 27% cpuidle.C4-ATM.usage
> 11321 ± 5% +55.3% 17582 ± 14% time.involuntary_context_switches
> 156 ± 14% -29.6% 110 ± 19% cpuidle.POLL.usage
> 50583 ± 2% -21.7% 39630 ± 4% cpuidle.C6-ATM.usage
> 51597156 ± 2% +23.7% 63848564 ± 3% cpuidle.C1E-ATM.time
> 39349 ± 2% -12.0% 34622 ± 2% softirqs.SCHED
> 758790 ± 8% -15.3% 642336 ± 12% sched_debug.cpu#2.sched_count
> 378981 ± 8% -15.6% 319776 ± 12% sched_debug.cpu#2.ttwu_count
> 374440 ± 8% -15.5% 316513 ± 12% sched_debug.cpu#2.ttwu_local
> 5307 ± 0% -1.0% 5255 ± 0% vmstat.system.in
>
> testbox/testcase/testparams: wsm/will-it-scale/performance-open2
>
> e3663b1024d1f946 00f5159aeb68f08ce29597be86
> ---------------- --------------------------
> 22128 ± 3% +120.2% 48719 ± 8% will-it-scale.time.involuntary_context_switches
> 5577 ± 45% +1492.2% 88802 ± 33% sched_debug.cpu#6.sched_count
> 5457 ± 46% +1526.2% 88751 ± 33% sched_debug.cpu#6.nr_switches
> 0.45 ± 43% -73.3% 0.12 ± 15% turbostat.%c3
> 10 ± 24% -55.8% 4 ± 40% sched_debug.cpu#9.nr_uninterruptible
> 147 ± 11% -58.5% 61 ± 32% sched_debug.cpu#11.load
> 147 ± 11% -58.5% 61 ± 32% sched_debug.cfs_rq[11]:/.load
> 10821106 ± 39% -59.8% 4347430 ± 20% cpuidle.C3-NHM.time
> 356 ± 41% +76.6% 629 ± 3% sched_debug.cfs_rq[6]:/.blocked_load_avg
> 22128 ± 3% +120.2% 48719 ± 8% time.involuntary_context_switches
> 145 ± 36% -35.9% 93 ± 30% sched_debug.cpu#5.load
> 469 ± 29% +55.9% 732 ± 4% sched_debug.cfs_rq[6]:/.tg_load_contrib
> 145 ± 36% -34.0% 95 ± 29% sched_debug.cfs_rq[5]:/.load
> 99 ± 8% -27.8% 72 ± 24% sched_debug.cpu#9.load
> 99 ± 8% -27.8% 72 ± 24% sched_debug.cfs_rq[9]:/.load
> 219871 ± 6% -33.3% 146545 ± 19% sched_debug.cpu#3.ttwu_local
> 224610 ± 6% -31.3% 154342 ± 18% sched_debug.cpu#3.sched_goidle
> 451877 ± 6% -31.1% 311378 ± 18% sched_debug.cpu#3.sched_count
> 451737 ± 6% -31.1% 311279 ± 18% sched_debug.cpu#3.nr_switches
> 225208 ± 6% -31.3% 154688 ± 18% sched_debug.cpu#3.ttwu_count
> 4122 ± 7% -23.6% 3148 ± 17% cpuidle.C3-NHM.usage
> 84 ± 11% -27.4% 61 ± 5% sched_debug.cpu#7.cpu_load[0]
> 154565 ± 2% -29.6% 108768 ± 9% cpuidle.C6-NHM.usage
> 124949 ± 25% +41.4% 176670 ± 15% sched_debug.cpu#2.sched_goidle
> 74177 ± 2% -23.6% 56653 ± 4% sched_debug.cpu#3.nr_load_updates
> 79 ± 6% -23.1% 60 ± 5% sched_debug.cpu#7.cpu_load[1]
> 50107 ± 6% -20.9% 39621 ± 7% sched_debug.cfs_rq[3]:/.exec_clock
> 76 ± 4% -20.6% 60 ± 6% sched_debug.cpu#7.cpu_load[2]
> 385983 ± 9% -20.4% 307347 ± 12% sched_debug.cfs_rq[3]:/.min_vruntime
> 74 ± 2% -18.5% 60 ± 6% sched_debug.cpu#7.cpu_load[3]
> 1.50 ± 6% -10.0% 1.35 ± 9% perf-profile.cpu-cycles.selinux_file_free_security.security_file_free.__fput.____fput.task_work_run
> 46086 ± 1% -25.7% 34260 ± 5% softirqs.SCHED
> 72 ± 1% -15.9% 60 ± 7% sched_debug.cpu#7.cpu_load[4]
> 74 ± 13% -17.7% 61 ± 2% sched_debug.cfs_rq[7]:/.runnable_load_avg
> 65 ± 2% +16.9% 76 ± 4% sched_debug.cpu#1.cpu_load[3]
> 1.94 ± 5% -9.9% 1.74 ± 6% perf-profile.cpu-cycles.security_file_free.__fput.____fput.task_work_run.do_notify_resume
> 58851 ± 1% +20.5% 70942 ± 9% sched_debug.cfs_rq[1]:/.exec_clock
> 69880 ± 1% -16.9% 58047 ± 11% sched_debug.cpu#7.nr_load_updates
> 60 ± 5% +9.5% 66 ± 3% sched_debug.cpu#9.cpu_load[4]
> 12064 ± 7% +12.4% 13561 ± 5% slabinfo.kmalloc-64.num_objs
> 67 ± 4% +14.9% 77 ± 4% sched_debug.cpu#1.cpu_load[2]
> 53070 ± 7% +18.3% 62803 ± 5% sched_debug.cfs_rq[9]:/.exec_clock
> 64 ± 1% +16.3% 74 ± 4% sched_debug.cpu#1.cpu_load[4]
> 11895 ± 7% +12.9% 13429 ± 5% slabinfo.kmalloc-64.active_objs
> 67415 ± 1% -16.4% 56345 ± 11% sched_debug.cfs_rq[7]:/.exec_clock
> 58403 ± 4% +12.0% 65434 ± 6% sched_debug.cpu#9.nr_load_updates
> 428535 ± 8% +18.3% 507136 ± 6% sched_debug.cfs_rq[9]:/.min_vruntime
> 505551 ± 1% +16.3% 588207 ± 8% sched_debug.cfs_rq[1]:/.min_vruntime
> 1818 ± 5% -8.4% 1665 ± 3% slabinfo.proc_inode_cache.active_objs
> 1818 ± 5% -8.4% 1665 ± 3% slabinfo.proc_inode_cache.num_objs
> 616 ± 0% +11.4% 686 ± 4% sched_debug.cfs_rq[1]:/.tg_runnable_contrib
> 2259 ± 14% +23.5% 2790 ± 5% sched_debug.cpu#3.curr->pid
> 28336 ± 0% +11.2% 31517 ± 4% sched_debug.cfs_rq[1]:/.avg->runnable_avg_sum
> 576795 ± 1% -14.6% 492717 ± 10% sched_debug.cfs_rq[7]:/.min_vruntime
> 7176 ± 0% +2.1% 7323 ± 0% vmstat.system.cs
> 10798 ± 0% -1.1% 10675 ± 0% vmstat.system.in
>
> lkp-a03: Atom
> Memory: 8G
>
> wsm: Westmere
> Memory: 6G
>
>
>
>
> will-it-scale.time.involuntary_context_switches
>
> 70000 ++------------------------------------------------------------------+
> | |
> 60000 ++ O |
> O O O O O O O O O O |
> 50000 ++ O O O O O O O O
> | O O O O O O |
> 40000 ++ O O O O O |
> | |
> 30000 ++ |
> | .*. .*.*.. .* |
> 20000 *+*..* *..*.* *.*.*..*.*.*. *.*.*..*.*.*..*.*.*..* |
> | : : |
> 10000 ++ : : |
> | :: |
> 0 ++--------------*---------------------------------------------------+
>
>
> [*] bisect-good sample
> [O] bisect-bad sample
>
> 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
>
>
> ---
> testcase: will-it-scale
> default-monitors:
> wait: pre-test
> uptime:
> iostat:
> vmstat:
> numa-numastat:
> numa-vmstat:
> numa-meminfo:
> proc-vmstat:
> proc-stat:
> meminfo:
> slabinfo:
> interrupts:
> lock_stat:
> latency_stats:
> softirqs:
> bdi_dev_mapping:
> diskstats:
> cpuidle:
> cpufreq:
> turbostat:
> sched_debug:
> interval: 10
> pmeter:
> default_watchdogs:
> watch-oom:
> watchdog:
> cpufreq_governor:
> - performance
> commit: 634b0bd490b7ebd7a054cea4f7e0d25748bde678
> model: Westmere
> memory: 6G
> nr_hdd_partitions: 1
> hdd_partitions:
> swap_partitions:
> rootfs_partition:
> netconsole_port: 6667
> perf-profile:
> freq: 800
> will-it-scale:
> test:
> - open2
> testbox: wsm
> tbox_group: wsm
> kconfig: x86_64-rhel
> enqueue_time: 2015-01-16 17:43:47.976990621 +08:00
> head_commit: 634b0bd490b7ebd7a054cea4f7e0d25748bde678
> base_commit: eaa27f34e91a14cdceed26ed6c6793ec1d186115
> branch: next/master
> kernel: "/kernel/x86_64-rhel/634b0bd490b7ebd7a054cea4f7e0d25748bde678/vmlinuz-3.19.0-rc4-next-20150116-g634b0bd"
> user: lkp
> queue: cyclic
> rootfs: debian-x86_64-2015-01-13.cgz
> result_root: "/result/wsm/will-it-scale/performance-open2/debian-x86_64-2015-01-13.cgz/x86_64-rhel/634b0bd490b7ebd7a054cea4f7e0d25748bde678/0"
> job_file: "/lkp/scheduled/wsm/cyclic_will-it-scale-performance-open2-x86_64-rhel-HEAD-634b0bd490b7ebd7a054cea4f7e0d25748bde678-0.yaml"
> dequeue_time: 2015-01-16 23:50:07.247065623 +08:00
> nr_cpu: "$(nproc)"
> job_state: finished
> loadavg: 8.12 4.97 2.06 1/146 6693
> start_time: '1421423439'
> end_time: '1421423743'
> version: "/lkp/lkp/.src-20150116-113525"
> ./runtest.py open2 32 1 6 9 12
> _______________________________________________
> LKP mailing list
> LKP@linux.intel.com
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [LKP] [rcu] 00f5159aeb6: +55.3% will-it-scale.time.involuntary_context_switches
2015-01-21 7:52 ` Paul E. McKenney
@ 2015-01-21 8:06 ` Mike Galbraith
2015-01-21 8:54 ` Paul E. McKenney
0 siblings, 1 reply; 4+ messages in thread
From: Mike Galbraith @ 2015-01-21 8:06 UTC (permalink / raw)
To: paulmck; +Cc: Huang Ying, LKML, LKP ML
On Tue, 2015-01-20 at 23:52 -0800, Paul E. McKenney wrote:
> On Wed, Jan 21, 2015 at 03:32:44PM +0800, Huang Ying wrote:
> > FYI, we noticed the below changes on
> >
> > git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git stall.2015.01.06a
> > commit 00f5159aeb68f08ce29597be86be87d6db0c1ba1 ("rcu: Run grace-period kthreads at real-time priority")
>
> Glad this helps!
The way I read it, it's hurting by increasing context switches... but if
you'll need a boot param to turn it on in the future, this is moot :)
-Mike
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [LKP] [rcu] 00f5159aeb6: +55.3% will-it-scale.time.involuntary_context_switches
2015-01-21 8:06 ` Mike Galbraith
@ 2015-01-21 8:54 ` Paul E. McKenney
0 siblings, 0 replies; 4+ messages in thread
From: Paul E. McKenney @ 2015-01-21 8:54 UTC (permalink / raw)
To: Mike Galbraith; +Cc: Huang Ying, LKML, LKP ML
On Wed, Jan 21, 2015 at 09:06:47AM +0100, Mike Galbraith wrote:
> On Tue, 2015-01-20 at 23:52 -0800, Paul E. McKenney wrote:
> > On Wed, Jan 21, 2015 at 03:32:44PM +0800, Huang Ying wrote:
> > > FYI, we noticed the below changes on
> > >
> > > git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git stall.2015.01.06a
> > > commit 00f5159aeb68f08ce29597be86be87d6db0c1ba1 ("rcu: Run grace-period kthreads at real-time priority")
> >
> > Glad this helps!
>
> The way I read it, it's hurting by increasing context switches... but if
> you'll need a boot param to turn it on in the future, this is moot :)
Heh! I guess I should read it more carefully. Anyway, the commit does
help in some heavy-load situations, but something more deft is clearly
required if it is to be enabled more generally.
Thanx, Paul
^ permalink raw reply [flat|nested] 4+ messages in thread
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2015-01-21 7:32 [LKP] [rcu] 00f5159aeb6: +55.3% will-it-scale.time.involuntary_context_switches Huang Ying
2015-01-21 7:52 ` Paul E. McKenney
2015-01-21 8:06 ` Mike Galbraith
2015-01-21 8:54 ` Paul E. McKenney
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