>-----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]; linux-kernel@vger.kernel.org; >[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 Thanks, Venki - 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/
