From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?q?B=C3=A1lint=20Czobor?= Subject: [PATCH 40/70] cpufreq: interactive: fix deadlock on spinlock in timer Date: Tue, 27 Oct 2015 18:30:28 +0100 Message-ID: <1445967059-6897-40-git-send-email-czoborbalint@gmail.com> References: <1445967059-6897-1-git-send-email-czoborbalint@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1445967059-6897-1-git-send-email-czoborbalint@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: "Rafael J. Wysocki" , Viresh Kumar Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Todd Poynor , =?UTF-8?q?B=C3=A1lint=20Czobor?= List-Id: linux-pm@vger.kernel.org =46rom: Todd Poynor Need to use irqsave/restore spinlock calls to avoid a deadlock in calls from the timer. Change-Id: I15b6b590045ba1447e34ca7b5ff342723e53a605 Signed-off-by: Todd Poynor Signed-off-by: B=C3=A1lint Czobor --- drivers/cpufreq/cpufreq_interactive.c | 29 +++++++++++++++++--------= ---- 1 file changed, 17 insertions(+), 12 deletions(-) diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cp= ufreq_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 =3D jiffies + usecs_to_jiffies(timer_rate); + unsigned long flags; =20 mod_timer_pinned(&pcpu->cpu_timer, expires); if (timer_slack_val >=3D 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); } =20 - spin_lock(&pcpu->load_lock); + spin_lock_irqsave(&pcpu->load_lock, flags); pcpu->time_in_idle =3D get_cpu_idle_time_us(smp_processor_id(), &pcpu->time_in_idle_timestamp); pcpu->cputime_speedadj =3D 0; pcpu->cputime_speedadj_timestamp =3D pcpu->time_in_idle_timestamp; - spin_unlock(&pcpu->load_lock); + spin_unlock_irqrestore(&pcpu->load_lock, flags); } =20 static unsigned int freq_to_targetload(unsigned int freq) { int i; unsigned int ret; + unsigned long flags; =20 - spin_lock(&target_loads_lock); + spin_lock_irqsave(&target_loads_lock, flags); =20 for (i =3D 0; i < ntarget_loads - 1 && freq >=3D target_loads[i+1]; i= +=3D 2) ; =20 ret =3D target_loads[i]; - spin_unlock(&target_loads_lock); + spin_unlock_irqrestore(&target_loads_lock, flags); return ret; } =20 @@ -284,11 +286,11 @@ static void cpufreq_interactive_timer(unsigned lo= ng data) if (!pcpu->governor_enabled) goto exit; =20 - spin_lock(&pcpu->load_lock); + spin_lock_irqsave(&pcpu->load_lock, flags); now =3D update_load(data); delta_time =3D (unsigned int)(now - pcpu->cputime_speedadj_timestamp)= ; cputime_speedadj =3D pcpu->cputime_speedadj; - spin_unlock(&pcpu->load_lock); + spin_unlock_irqrestore(&pcpu->load_lock, flags); =20 if (WARN_ON_ONCE(!delta_time)) goto rearm; @@ -549,6 +551,7 @@ static int cpufreq_interactive_notifier( struct cpufreq_freqs *freq =3D data; struct cpufreq_interactive_cpuinfo *pcpu; int cpu; + unsigned long flags; =20 if (val =3D=3D CPUFREQ_POSTCHANGE) { pcpu =3D &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 =3D &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); } =20 up_read(&pcpu->enable_sem); @@ -581,15 +584,16 @@ static ssize_t show_target_loads( { int i; ssize_t ret =3D 0; + unsigned long flags; =20 - spin_lock(&target_loads_lock); + spin_lock_irqsave(&target_loads_lock, flags); =20 for (i =3D 0; i < ntarget_loads; i++) ret +=3D sprintf(buf + ret, "%u%s", target_loads[i], i & 0x1 ? ":" : " "); =20 ret +=3D sprintf(buf + ret, "\n"); - spin_unlock(&target_loads_lock); + spin_unlock_irqrestore(&target_loads_lock, flags); return ret; } =20 @@ -602,6 +606,7 @@ static ssize_t store_target_loads( unsigned int *new_target_loads =3D NULL; int ntokens =3D 1; int i; + unsigned long flags; =20 cp =3D buf; while ((cp =3D strpbrk(cp + 1, " :"))) @@ -631,12 +636,12 @@ static ssize_t store_target_loads( if (i !=3D ntokens) goto err_inval; =20 - spin_lock(&target_loads_lock); + spin_lock_irqsave(&target_loads_lock, flags); if (target_loads !=3D default_target_loads) kfree(target_loads); target_loads =3D new_target_loads; ntarget_loads =3D ntokens; - spin_unlock(&target_loads_lock); + spin_unlock_irqrestore(&target_loads_lock, flags); return count; =20 err_inval: --=20 1.7.9.5