From c7ad1e1b900f63c175f16b503755402c48fef0c6 Mon Sep 17 00:00:00 2001 From: Todd Poynor Date: Wed, 2 Jan 2013 13:14:00 -0800 Subject: [PATCH] cpufreq: interactive: fix deadlock on spinlock in timer Need to use irqsave/restore spinlock calls to avoid a deadlock in calls from the timer. Change-Id: I15b6b590045ba1447e34ca7b5ff342723e53a605 Signed-off-by: Todd Poynor --- 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 51c34bf9c173..e7f26aae186b 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: -- 2.34.1