| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Tue, 27 Oct 2015 18:30:49 +0100
From: Bálint Czobor <czoborbalint@...il.com>
To: "Rafael J. Wysocki" <rjw@...ysocki.net>,
Viresh Kumar <viresh.kumar@...aro.org>
Cc: linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
Badhri Jagan Sridharan <Badhri@...gle.com>,
Bálint Czobor <czoborbalint@...il.com>
Subject: [PATCH 61/70] cpufreq: interactive: restructure CPUFREQ_GOV_LIMITS
From: Badhri Jagan Sridharan <Badhri@...gle.com>
The cpufreq_interactive_timer gets cancelled and rescheduled
whenever the cpufreq_policy is changed. When the cpufreq policy is
changed at a rate faster than the sampling_rate of the interactive
governor, then the governor misses to change the target frequency
for long duration. The patch removes the need of cancelling the
timers when policy->min is changed.
Signed-off-by: Badhri Jagan Sridharan <Badhri@...gle.com>
Change-Id: Ibd98d151e1c73b8bd969484583ff98ee9f1135ef
Signed-off-by: Bálint Czobor <czoborbalint@...il.com>
---
drivers/cpufreq/cpufreq_interactive.c | 48 ++++++++++++++++++++++++---------
1 file changed, 35 insertions(+), 13 deletions(-)
diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cpufreq_interactive.c
index 786fd01..0e3e45e 100644
--- a/drivers/cpufreq/cpufreq_interactive.c
+++ b/drivers/cpufreq/cpufreq_interactive.c
@@ -44,8 +44,10 @@ struct cpufreq_interactive_cpuinfo {
u64 cputime_speedadj_timestamp;
struct cpufreq_policy *policy;
struct cpufreq_frequency_table *freq_table;
+ spinlock_t target_freq_lock; /*protects target freq */
unsigned int target_freq;
unsigned int floor_freq;
+ unsigned int max_freq;
u64 floor_validate_time;
u64 hispeed_validate_time;
struct rw_semaphore enable_sem;
@@ -358,6 +360,7 @@ static void cpufreq_interactive_timer(unsigned long data)
if (WARN_ON_ONCE(!delta_time))
goto rearm;
+ spin_lock_irqsave(&pcpu->target_freq_lock, flags);
do_div(cputime_speedadj, delta_time);
loadadjfreq = (unsigned int)cputime_speedadj * 100;
cpu_load = loadadjfreq / pcpu->target_freq;
@@ -383,6 +386,7 @@ static void cpufreq_interactive_timer(unsigned long data)
trace_cpufreq_interactive_notyet(
data, cpu_load, pcpu->target_freq,
pcpu->policy->cur, new_freq);
+ spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
goto rearm;
}
@@ -390,8 +394,10 @@ static void cpufreq_interactive_timer(unsigned long data)
if (cpufreq_frequency_table_target(pcpu->policy, pcpu->freq_table,
new_freq, CPUFREQ_RELATION_L,
- &index))
+ &index)) {
+ spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
goto rearm;
+ }
new_freq = pcpu->freq_table[index].frequency;
@@ -405,6 +411,7 @@ static void cpufreq_interactive_timer(unsigned long data)
trace_cpufreq_interactive_notyet(
data, cpu_load, pcpu->target_freq,
pcpu->policy->cur, new_freq);
+ spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
goto rearm;
}
}
@@ -426,6 +433,7 @@ static void cpufreq_interactive_timer(unsigned long data)
trace_cpufreq_interactive_already(
data, cpu_load, pcpu->target_freq,
pcpu->policy->cur, new_freq);
+ spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
goto rearm_if_notmax;
}
@@ -433,6 +441,7 @@ static void cpufreq_interactive_timer(unsigned long data)
pcpu->policy->cur, new_freq);
pcpu->target_freq = new_freq;
+ spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
spin_lock_irqsave(&speedchange_cpumask_lock, flags);
cpumask_set_cpu(data, &speedchange_cpumask);
spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
@@ -576,16 +585,17 @@ static void cpufreq_interactive_boost(void)
{
int i;
int anyboost = 0;
- unsigned long flags;
+ unsigned long flags[2];
struct cpufreq_interactive_cpuinfo *pcpu;
struct cpufreq_interactive_tunables *tunables;
- spin_lock_irqsave(&speedchange_cpumask_lock, flags);
+ spin_lock_irqsave(&speedchange_cpumask_lock, flags[0]);
for_each_online_cpu(i) {
pcpu = &per_cpu(cpuinfo, i);
tunables = pcpu->policy->governor_data;
+ spin_lock_irqsave(&pcpu->target_freq_lock, flags[1]);
if (pcpu->target_freq < tunables->hispeed_freq) {
pcpu->target_freq = tunables->hispeed_freq;
cpumask_set_cpu(i, &speedchange_cpumask);
@@ -601,9 +611,10 @@ static void cpufreq_interactive_boost(void)
pcpu->floor_freq = tunables->hispeed_freq;
pcpu->floor_validate_time = ktime_to_us(ktime_get());
+ spin_unlock_irqrestore(&pcpu->target_freq_lock, flags[1]);
}
- spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
+ spin_unlock_irqrestore(&speedchange_cpumask_lock, flags[0]);
if (anyboost)
wake_up_process(speedchange_task);
@@ -1114,6 +1125,7 @@ static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
struct cpufreq_interactive_cpuinfo *pcpu;
struct cpufreq_frequency_table *freq_table;
struct cpufreq_interactive_tunables *tunables;
+ unsigned long flags;
if (have_governor_per_policy())
tunables = policy->governor_data;
@@ -1215,6 +1227,7 @@ static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
ktime_to_us(ktime_get());
pcpu->hispeed_validate_time =
pcpu->floor_validate_time;
+ pcpu->max_freq = policy->max;
down_write(&pcpu->enable_sem);
del_timer_sync(&pcpu->cpu_timer);
del_timer_sync(&pcpu->cpu_slack_timer);
@@ -1250,29 +1263,37 @@ static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
for_each_cpu(j, policy->cpus) {
pcpu = &per_cpu(cpuinfo, j);
- /* hold write semaphore to avoid race */
- down_write(&pcpu->enable_sem);
+ down_read(&pcpu->enable_sem);
if (pcpu->governor_enabled == 0) {
- up_write(&pcpu->enable_sem);
+ up_read(&pcpu->enable_sem);
continue;
}
- /* update target_freq firstly */
+ spin_lock_irqsave(&pcpu->target_freq_lock, flags);
if (policy->max < pcpu->target_freq)
pcpu->target_freq = policy->max;
else if (policy->min > pcpu->target_freq)
pcpu->target_freq = policy->min;
- /* Reschedule timer.
+ spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
+ up_read(&pcpu->enable_sem);
+
+ /* Reschedule timer only if policy->max is raised.
* Delete the timers, else the timer callback may
* return without re-arm the timer when failed
* acquire the semaphore. This race may cause timer
* stopped unexpectedly.
*/
- del_timer_sync(&pcpu->cpu_timer);
- del_timer_sync(&pcpu->cpu_slack_timer);
- cpufreq_interactive_timer_start(tunables, j);
- up_write(&pcpu->enable_sem);
+
+ if (policy->max > pcpu->max_freq) {
+ down_write(&pcpu->enable_sem);
+ del_timer_sync(&pcpu->cpu_timer);
+ del_timer_sync(&pcpu->cpu_slack_timer);
+ cpufreq_interactive_timer_start(tunables, j);
+ up_write(&pcpu->enable_sem);
+ }
+
+ pcpu->max_freq = policy->max;
}
break;
}
@@ -1308,6 +1329,7 @@ static int __init cpufreq_interactive_init(void)
init_timer(&pcpu->cpu_slack_timer);
pcpu->cpu_slack_timer.function = cpufreq_interactive_nop_timer;
spin_lock_init(&pcpu->load_lock);
+ spin_lock_init(&pcpu->target_freq_lock);
init_rwsem(&pcpu->enable_sem);
}
--
1.7.9.5
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists