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Groups > linux.kernel > #1257088

[PATCH 40/70] cpufreq: interactive: fix deadlock on spinlock in timer

From Bálint Czobor <czoborbalint@gmail.com>
Newsgroups linux.kernel
Subject [PATCH 40/70] cpufreq: interactive: fix deadlock on spinlock in timer
Date 2015-10-27 19:00 +0100
Message-ID <qogHp-8bo-55@gated-at.bofh.it> (permalink)
References <qogo1-84h-5@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


From: Todd Poynor <toddpoynor@google.com>

Need to use irqsave/restore spinlock calls to avoid a deadlock in calls
from the timer.

Change-Id: I15b6b590045ba1447e34ca7b5ff342723e53a605
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Bálint Czobor <czoborbalint@gmail.com>
---
 drivers/cpufreq/cpufreq_interactive.c |   29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cpufreq_interactive.c
index 51c34bf..e7f26aa 100644
--- a/drivers/cpufreq/cpufreq_interactive.c
+++ b/drivers/cpufreq/cpufreq_interactive.c
@@ -126,6 +126,7 @@ static void cpufreq_interactive_timer_resched(
 	struct cpufreq_interactive_cpuinfo *pcpu)
 {
 	unsigned long expires = jiffies + usecs_to_jiffies(timer_rate);
+	unsigned long flags;
 
 	mod_timer_pinned(&pcpu->cpu_timer, expires);
 	if (timer_slack_val >= 0 && pcpu->target_freq > pcpu->policy->min) {
@@ -133,27 +134,28 @@ static void cpufreq_interactive_timer_resched(
 		mod_timer_pinned(&pcpu->cpu_slack_timer, expires);
 	}
 
-	spin_lock(&pcpu->load_lock);
+	spin_lock_irqsave(&pcpu->load_lock, flags);
 	pcpu->time_in_idle =
 		get_cpu_idle_time_us(smp_processor_id(),
 				     &pcpu->time_in_idle_timestamp);
 	pcpu->cputime_speedadj = 0;
 	pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
-	spin_unlock(&pcpu->load_lock);
+	spin_unlock_irqrestore(&pcpu->load_lock, flags);
 }
 
 static unsigned int freq_to_targetload(unsigned int freq)
 {
 	int i;
 	unsigned int ret;
+	unsigned long flags;
 
-	spin_lock(&target_loads_lock);
+	spin_lock_irqsave(&target_loads_lock, flags);
 
 	for (i = 0; i < ntarget_loads - 1 && freq >= target_loads[i+1]; i += 2)
 		;
 
 	ret = target_loads[i];
-	spin_unlock(&target_loads_lock);
+	spin_unlock_irqrestore(&target_loads_lock, flags);
 	return ret;
 }
 
@@ -284,11 +286,11 @@ static void cpufreq_interactive_timer(unsigned long data)
 	if (!pcpu->governor_enabled)
 		goto exit;
 
-	spin_lock(&pcpu->load_lock);
+	spin_lock_irqsave(&pcpu->load_lock, flags);
 	now = update_load(data);
 	delta_time = (unsigned int)(now - pcpu->cputime_speedadj_timestamp);
 	cputime_speedadj = pcpu->cputime_speedadj;
-	spin_unlock(&pcpu->load_lock);
+	spin_unlock_irqrestore(&pcpu->load_lock, flags);
 
 	if (WARN_ON_ONCE(!delta_time))
 		goto rearm;
@@ -549,6 +551,7 @@ static int cpufreq_interactive_notifier(
 	struct cpufreq_freqs *freq = data;
 	struct cpufreq_interactive_cpuinfo *pcpu;
 	int cpu;
+	unsigned long flags;
 
 	if (val == CPUFREQ_POSTCHANGE) {
 		pcpu = &per_cpu(cpuinfo, freq->cpu);
@@ -562,9 +565,9 @@ static int cpufreq_interactive_notifier(
 		for_each_cpu(cpu, pcpu->policy->cpus) {
 			struct cpufreq_interactive_cpuinfo *pjcpu =
 				&per_cpu(cpuinfo, cpu);
-			spin_lock(&pjcpu->load_lock);
+			spin_lock_irqsave(&pjcpu->load_lock, flags);
 			update_load(cpu);
-			spin_unlock(&pjcpu->load_lock);
+			spin_unlock_irqrestore(&pjcpu->load_lock, flags);
 		}
 
 		up_read(&pcpu->enable_sem);
@@ -581,15 +584,16 @@ static ssize_t show_target_loads(
 {
 	int i;
 	ssize_t ret = 0;
+	unsigned long flags;
 
-	spin_lock(&target_loads_lock);
+	spin_lock_irqsave(&target_loads_lock, flags);
 
 	for (i = 0; i < ntarget_loads; i++)
 		ret += sprintf(buf + ret, "%u%s", target_loads[i],
 			       i & 0x1 ? ":" : " ");
 
 	ret += sprintf(buf + ret, "\n");
-	spin_unlock(&target_loads_lock);
+	spin_unlock_irqrestore(&target_loads_lock, flags);
 	return ret;
 }
 
@@ -602,6 +606,7 @@ static ssize_t store_target_loads(
 	unsigned int *new_target_loads = NULL;
 	int ntokens = 1;
 	int i;
+	unsigned long flags;
 
 	cp = buf;
 	while ((cp = strpbrk(cp + 1, " :")))
@@ -631,12 +636,12 @@ static ssize_t store_target_loads(
 	if (i != ntokens)
 		goto err_inval;
 
-	spin_lock(&target_loads_lock);
+	spin_lock_irqsave(&target_loads_lock, flags);
 	if (target_loads != default_target_loads)
 		kfree(target_loads);
 	target_loads = new_target_loads;
 	ntarget_loads = ntokens;
-	spin_unlock(&target_loads_lock);
+	spin_unlock_irqrestore(&target_loads_lock, flags);
 	return count;
 
 err_inval:
-- 
1.7.9.5

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Thread

[PATCH 01/70] cpufreq: interactive: New 'interactive' governor Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 57/70] cpufreq: interactive: fix compiling warnings Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 56/70] cpufreq: interactive: delete timers for GOV_START Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 41/70] cpufreq: interactive: fix race on governor start/stop Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 32/70] cpufreq: interactive: specify duration of CPU speed boost pulse Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 43/70] cpufreq: interactive: add io_is_busy interface Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 39/70] cpufreq: interactive: don't handle transition notification if not enabled Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 51/70] cpufreq: interactive: resched timer if max freq raised Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 09/70] cpufreq: interactive: Separate speed target revalidate time and initial set time Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 60/70] cpufreq: interactive: hold reference on global cpufreq kobject if needed Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 24/70] cpufreq: interactive: use deferrable timer by default Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 61/70] cpufreq: interactive: restructure CPUFREQ_GOV_LIMITS Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 27/70] cpufreq: interactive: change speed according to current speed and target load Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 07/70] cpufreq: interactive: adjust code and documentation to match Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 29/70] cpufreq: interactive: allow arbitrary speed / target load mappings Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 48/70] cpufreq: interactive: reduce chance of zero time delta on load eval Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 64/70] cpufreq: interactive: prevents the frequency to directly raise above the hispeed_freq from a lower frequency. Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 65/70] cpufreq: interactive: make common_tunables static Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 69/70] cpufreq: interactive: Don't set floor_validate_time during boost Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 37/70] cpufreq: interactive: default go_hispeed_load 99%, doc updates Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 58/70] cpufreq: interactive: fix NULL pointer dereference at sysfs ops Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 66/70] cpufreq: interactive: Fix compile errors in accordance with changes from 3.14 to 3.18 Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 17/70] cpufreq: interactive: take idle notifications only when active Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 35/70] cpufreq: interactive: fix racy timer stopping Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 67/70] cpufreq: interactive: Put global cpufreq kobject on failure Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 70/70] cpufreq: interactive: Round up timer_rate to match jiffy Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 20/70] cpufreq: interactive: remove input_boost handling Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 12/70] cpufreq: interactive: Add sysfs boost interface for hints from userspace Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 22/70] cpufreq: interactive: run at fraction of hispeed_freq when load is low Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 68/70] subsystem: CPU FREQUENCY DRIVERS- Set cpu_load calculation on current frequency Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 13/70] cpufreq: interactive: set floor for boosted speed Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 55/70] cpufreq: Interactive: Implement per policy instances of governor Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 52/70] cpufreq: interactive: fix show_target_loads and show_above_hispeed_delay Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 10/70] cpufreq: interactive: Boost frequency on touchscreen input Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 62/70] cpufreq: interactive: turn boost_pulse off on boost off Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 59/70] cpufreq: interactive: Use generic get_cpu_idle_time() from cpufreq.c Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 54/70] cpufreq: interactive: Move definition of cpufreq_gov_interactive downwards Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 53/70] cpufreq: interactive: Remove unnecessary cpu_online() check Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 25/70] cpufreq: interactive: kick timer on idle exit past expiry Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 47/70] cpufreq: interactive: handle errors from cpufreq_frequency_table_target Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 63/70] cpufreq: interactive: remove compilation error from commit 49cc72365fb7ee87762a7ccc6a32ef68627216c5 Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 44/70] cpufreq: interactive: fix crash on error paths in get_tokenized_data Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 50/70] cpufreq: interactive: fix race on cpufreq TRANSITION notifier Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 49/70] cpufreq: interactive: avoid underflow on active time calculation Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 45/70] cpufreq: interactive: base above_hispeed_delay on target freq, not current Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 46/70] cpufreq: interactive: fix uninitialized spinlock Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 34/70] cpufreq: interactive: fix boosting logic Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 38/70] cpufreq: interactive: init default values at compile time Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 16/70] cpufreq: interactive: restart above_hispeed_delay at each hispeed load Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 28/70] cpufreq: interactive: apply above_hispeed_delay to each step above hispeed Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 23/70] cpufreq: interactive: pin timers to associated CPU Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 18/70] cpufreq: interactive: keep freezer happy when not current governor Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 21/70] cpufreq: interactive: always limit initial speed bump to hispeed Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 36/70] cpufreq: interactive: fix race on timer restart on governor start Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 19/70] cpufreq: interactive: handle speed up and down in the realtime task Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 42/70] cpufreq: interactive: allow arbitrary speed / delay mappings Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 26/70] cpufreq: interactive: trace actual speed in target speed decisions Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 30/70] cpufreq: interactive: remove load since last speed change Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 40/70] cpufreq: interactive: fix deadlock on spinlock in timer Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 33/70] cpufreq: interactive: add timer slack to limit idle at speed > min Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 31/70] cpufreq: interactive: adjust load for changes in speed Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 04/70] cpufreq: interactive: set at least hispeed when above hispeed load Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:10 +0100
  [PATCH 02/70] cpufreq interactive governor: event tracing Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:10 +0100
  [PATCH 11/70] cpufreq: interactive: remove unused target_validate_time_in_idle Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:10 +0100
  [PATCH 05/70] cpufreq: interactive: don't drop speed if recently at higher load Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:10 +0100
  [PATCH 06/70] cpufreq: interactive: configurable delay before raising above hispeed Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:10 +0100
  [PATCH 08/70] cpufreq: interactive: base hispeed bump on target freq, not actual Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:10 +0100
  [PATCH 15/70] cpufreq-interactive: Compile fixup Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:10 +0100
  [PATCH 14/70] cpufreq: interactive: add boost pulse interface Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:10 +0100
  Re: [PATCH 01/70] cpufreq: interactive: New 'interactive' governor "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2015-10-28 01:40 +0100
    Re: [PATCH 01/70] cpufreq: interactive: New 'interactive' governor Viresh Kumar <viresh.kumar@linaro.org> - 2015-10-28 04:10 +0100
      Re: [PATCH 01/70] cpufreq: interactive: New 'interactive' governor Viresh Kumar <viresh.kumar@linaro.org> - 2015-10-29 02:50 +0100

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