Should we add some sort of logging facility to powertop (maybe it already does?) to get history or log generated with decisions to switch pstate/cstate/intr rate or other parameters. This will help analyze running different workloads and see how our PAD scheduler was good/bad with choices made?
>-----Original Message----- >From: tesla-dev-bounces at opensolaris.org [mailto:tesla-dev-bounces at >opensolaris.org] On Behalf Of Bill >Holler >Sent: Thursday, December 04, 2008 12:03 PM >To: tesla-dev at opensolaris.org >Subject: [tesla-dev] Some experiments with C-state throttleing based on number >of active CPUs > >Hi Tesla Dev, > >I have been experimenting not going into C3 or C2 when >the number of non-idle CPUs in the cpu-partion exceeds >a threshold. This is an attempt to regain the high load performance. >These numbers are on a 2-socket system. > >With C3 threshold = 40% active and C2 threshold = 60% active >the libmicro fork_1000 benchmark completes in 80/100 the time. > >With C3 threshold = 20% active and C2 threshold = 30% active >the libmicro fork_1000 benchmark completes in 50/100 the time. >These numbers are still about 80/100 slower than with c-states >totally disabled. > > >I am also going to experiment with cpu idle/wakeup rate. >I suspect this may be more important for performance than >the number of active cpus. > >Regards, >Bill >_______________________________________________ >tesla-dev mailing list >tesla-dev at opensolaris.org >http://mail.opensolaris.org/mailman/listinfo/tesla-dev
