On Wed, 10 Aug 2005 04:44 pm, Thomas Renninger wrote: > Pallipadi, Venkatesh wrote: > >>-----Original Message----- > >>From: [EMAIL PROTECTED] > >>[mailto:[EMAIL PROTECTED] On Behalf Of > >>Stefan Seyfried > >>Sent: Sunday, August 07, 2005 10:43 PM > >>To: Con Kolivas > >>Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED]; > >>[EMAIL PROTECTED]; [email protected]; > >>[EMAIL PROTECTED] > >>Subject: Re: [patch] i386 dynamic ticks 2.6.13-rc4 (code reordered) > >> > >>Con Kolivas wrote: > >>>>When I enabled dynamic tick using: > >>>> > >>>> echo 1 > /sys/devices/system/timer/timer0/dyn_tick_state > >>>> > >>>>The number of ticks dropped down to 60-70 HZ, bus mastering activity > >>>>jumpped up to being almost always active, > >>> > >>>Anyone know why this would happen? > >> > >>This is just a guess, without any actual code-reading: > >>Maybe the C-state decision process just relies on being called every > >>tick, so "after X ticks with no BM activity, go to next deeper > >>C state". > >>As long as 1000 ticks per second are coming in, everything is fine and > >>we enter C[n+1] after X miliseconds without BM activity. Now if there > >>are only 60-70 ticks per second, you never get X ticks without BM > >>activity so you never go deeper than C2. > >> > >>Just a guess. > > > > That is correct. The C-state policy right now looks at jiffies to decide > > on which C-state to go to (instead of absolute time). > > This patch from Thomas should help with respect to going to proper > > C-state in presence of dynamic tick. > > http://lkml.org/lkml/2005/4/19/96 > > My patch considered only the average last idle times and the average last > bus master activities. > It could happen that C3/C4 comes in too fast (not waiting long enough for > bus master activity to settle down) which could result in failed > transitions or misfunctionality of bus master devices. > However, it worked on my machine and I could gain a lot of power savings. > But be prepared that your WLAN card, USB peripherie or others might behave > strangely or even that the machine freezes (if, it should freeze quite fast > if idle). > I plan to have a look at x86 and x86_64 dynamic tick patches again and > rewrite the C-state patch, soon. > Any hints on updated dyn-tick patches/projects crawling around are > appreciated.
The most current patch for 2.6.13-rc6 is: http://ck.kolivas.org/patches/dyn-ticks/2.6.13-rc6-dtck-1.patch but I would recommend waiting till Srivatsa gets out the SMP/updated version of this code as it may be quite different and you're best working off that codebase. Cheers, Con - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
