Messages in this thread Patch in this message | | | From | Mike Chan <> | Subject | [PATCH] cpufreq: ondemand: Don't synchronize sample rate unless mulitple cpus present | Date | Tue, 12 Jan 2010 18:14:30 -0800 |
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From: Jocelyn Falempe <jocelyn.falempe@motorola.com>
For UP systems this is not required, and results in a more consistent sample interval.
Signed-off-by: Jocelyn Falempe <jocelyn.falempe@motorola.com> Signed-off-by: Mike Chan <mike@android.com> --- drivers/cpufreq/cpufreq_ondemand.c | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index 4b34ade..d139558 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -576,7 +576,9 @@ static void do_dbs_timer(struct work_struct *work) /* We want all CPUs to do sampling nearly on same jiffy */ int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); - delay -= jiffies % delay; + if (num_online_cpus() > 1) + delay -= jiffies % delay; + mutex_lock(&dbs_info->timer_mutex); /* Common NORMAL_SAMPLE setup */ @@ -601,7 +603,9 @@ static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info) { /* We want all CPUs to do sampling nearly on same jiffy */ int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); - delay -= jiffies % delay; + + if (num_online_cpus() > 1) + delay -= jiffies % delay; dbs_info->sample_type = DBS_NORMAL_SAMPLE; INIT_DELAYED_WORK_DEFERRABLE(&dbs_info->work, do_dbs_timer); -- 1.6.6
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