From: Stephen Boyd <sboyd@codeaurora.org>
To: John Stultz <john.stultz@linaro.org>,
Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Mark Rutland <mark.rutland@arm.com>,
Marc Zyngier <Marc.Zyngier@arm.com>
Subject: Re: [PATCH] ARM: arch_timer: Silence debug preempt warnings
Date: Thu, 04 Apr 2013 22:11:24 -0700 [thread overview]
Message-ID: <515E5CFC.4090900@codeaurora.org> (raw)
In-Reply-To: <1364934672-31554-1-git-send-email-sboyd@codeaurora.org>
On 4/2/2013 1:31 PM, Stephen Boyd wrote:
> Hot-plugging with CONFIG_DEBUG_PREEMPT=y on a device with arm
> architected timers causes a slew of "using smp_processor_id() in
> preemptible" warnings:
>
> BUG: using smp_processor_id() in preemptible [00000000] code: sh/111
> caller is arch_timer_cpu_notify+0x14/0xc8
>
> This happens because sometimes the cpu notifier, arch_timer_cpu_notify(),
> is called in preemptible context but we use this_cpu_ptr()
> to retrieve the clockevent unconditionally. We're only going to
> actually use the pointer in non-preemptible context though,
> so use __this_cpu_ptr() instead to avoid the preemptible checks
> and silence the warning.
>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Marc Zyngier <Marc.Zyngier@arm.com>
> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
> ---
Anyone else seeing this one?
> drivers/clocksource/arm_arch_timer.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
> index d7ad425..5928c29 100644
> --- a/drivers/clocksource/arm_arch_timer.c
> +++ b/drivers/clocksource/arm_arch_timer.c
> @@ -248,7 +248,7 @@ static void __cpuinit arch_timer_stop(struct clock_event_device *clk)
> static int __cpuinit arch_timer_cpu_notify(struct notifier_block *self,
> unsigned long action, void *hcpu)
> {
> - struct clock_event_device *evt = this_cpu_ptr(arch_timer_evt);
> + struct clock_event_device *evt = __this_cpu_ptr(arch_timer_evt);
>
> switch (action & ~CPU_TASKS_FROZEN) {
> case CPU_STARTING:
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation
WARNING: multiple messages have this Message-ID (diff)
From: sboyd@codeaurora.org (Stephen Boyd)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: arch_timer: Silence debug preempt warnings
Date: Thu, 04 Apr 2013 22:11:24 -0700 [thread overview]
Message-ID: <515E5CFC.4090900@codeaurora.org> (raw)
In-Reply-To: <1364934672-31554-1-git-send-email-sboyd@codeaurora.org>
On 4/2/2013 1:31 PM, Stephen Boyd wrote:
> Hot-plugging with CONFIG_DEBUG_PREEMPT=y on a device with arm
> architected timers causes a slew of "using smp_processor_id() in
> preemptible" warnings:
>
> BUG: using smp_processor_id() in preemptible [00000000] code: sh/111
> caller is arch_timer_cpu_notify+0x14/0xc8
>
> This happens because sometimes the cpu notifier, arch_timer_cpu_notify(),
> is called in preemptible context but we use this_cpu_ptr()
> to retrieve the clockevent unconditionally. We're only going to
> actually use the pointer in non-preemptible context though,
> so use __this_cpu_ptr() instead to avoid the preemptible checks
> and silence the warning.
>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Marc Zyngier <Marc.Zyngier@arm.com>
> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
> ---
Anyone else seeing this one?
> drivers/clocksource/arm_arch_timer.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
> index d7ad425..5928c29 100644
> --- a/drivers/clocksource/arm_arch_timer.c
> +++ b/drivers/clocksource/arm_arch_timer.c
> @@ -248,7 +248,7 @@ static void __cpuinit arch_timer_stop(struct clock_event_device *clk)
> static int __cpuinit arch_timer_cpu_notify(struct notifier_block *self,
> unsigned long action, void *hcpu)
> {
> - struct clock_event_device *evt = this_cpu_ptr(arch_timer_evt);
> + struct clock_event_device *evt = __this_cpu_ptr(arch_timer_evt);
>
> switch (action & ~CPU_TASKS_FROZEN) {
> case CPU_STARTING:
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation
next prev parent reply other threads:[~2013-04-05 5:11 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-02 20:31 [PATCH] ARM: arch_timer: Silence debug preempt warnings Stephen Boyd
2013-04-02 20:31 ` Stephen Boyd
2013-04-05 5:11 ` Stephen Boyd [this message]
2013-04-05 5:11 ` Stephen Boyd
2013-04-05 10:04 ` Marc Zyngier
2013-04-05 10:04 ` Marc Zyngier
2013-04-05 20:12 ` Stephen Boyd
2013-04-05 20:12 ` Stephen Boyd
2013-04-05 20:12 ` Stephen Boyd
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