lkml.org 
[lkml]   [2011]   [Jun]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: power increase issue on light load
From
Date

>
> Looking at the schedstat data Alex posted:
> - Distribution of load balances across cores looks about the same.
> - Load balancer does more idle balances on 3.0-rc4 as compared to
> 2.6.39 on SMT and NUMA domains. Busy and newidle balances are a mixed
> bag.
> - I see far fewer affine wakeups on 3.0-rc4 as compared to 2.6.39.
> About half as many affine wakeups on SMT and about a quarter as many
> on NUMA.
>
> I'm investigating the impact of the load resolution patchset on
> effective load and wake affine calculations. This seems to be the most
> obvious difference from the schedstat data.
>
> Alex -- I have a couple of questions about your test setup and results.
> - What is the impact on throughput of these benchmarks?

both on bltk-office and light load specpower, 10%/20%/30% load, the
throughput almost have no change on my NHM-EP server and t410 laptop.
> - Would it be possible to get a "perf sched" trace on these two kernels?

I will run the testing again and give you data later. but I didn't find
more useful data in 'perf record -e sched*'.
> - I'm assuming the three sched domains are SMT, MC and NUMA. Is that
> right? Do you have any powersavings balance or special sched domain
> flags enabled?

Yes, and the sched_mc_power_savings and sched_smt_power_savings were
both set. the NHM-EP domain like below:

CPU15 attaching sched-domain:
domain 0: span 7,15 level SIBLING
groups: 15 (cpu_power = 589) 7 (cpu_power = 589)
domain 1: span 1,3,5,7,9,11,13,15 level MC
groups: 7,15 (cpu_power = 1178) 1,9 (cpu_power = 1178) 3,11 (cpu_power = 1178) 5,13 (cpu_power = 1178)
domain 2: span 0-15 level NODE
groups: 1,3,5,7,9,11,13,15 (cpu_power = 4712) 0,2,4,6,8,10,12,14 (cpu_power = 4712)

> - Are you using group scheduling? If so, what does your setup look like?

I enabled the FAIR group default. But I have tried to disable it. the
problem is same. so, it isn't related to group.
>
> -Thanks,
> Nikhil




\
 
 \ /
  Last update: 2011-06-29 05:29    [W:0.075 / U:0.392 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site