From: venkatesh.pallipadi@intel.com Date: Thu, 31 Jul 2008 02:21:44 +0000 (-0700) Subject: cpuidle: Make ladder governor honor latency requirements fully X-Git-Tag: v2.6.27-rc4~59^2^2 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=06d9e908b2248f983b186aaf569c58e1430db85d;p=linux-2.6 cpuidle: Make ladder governor honor latency requirements fully ladder governor only honored latency requirement when promoting C-states. Instead. it should check for latency requirement on each idle call, and demote to appropriate C-state when there is a latency requirement change. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Andi Kleen --- diff --git a/drivers/cpuidle/governors/ladder.c b/drivers/cpuidle/governors/ladder.c index 27ab3bfe37..a4bec3f919 100644 --- a/drivers/cpuidle/governors/ladder.c +++ b/drivers/cpuidle/governors/ladder.c @@ -98,6 +98,18 @@ static int ladder_select_state(struct cpuidle_device *dev) } /* consider demotion */ + if (last_idx > CPUIDLE_DRIVER_STATE_START && + dev->states[last_idx].exit_latency > latency_req) { + int i; + + for (i = last_idx - 1; i > CPUIDLE_DRIVER_STATE_START; i--) { + if (dev->states[i].exit_latency <= latency_req) + break; + } + ladder_do_selection(ldev, last_idx, i); + return i; + } + if (last_idx > CPUIDLE_DRIVER_STATE_START && last_residency < last_state->threshold.demotion_time) { last_state->stats.demotion_count++;