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From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Sebastian Siewior <bigeasy@linutronix.de>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [patch V2 08/24] hwtracing/coresight-etm3x: Use cpuhp_setup_state_nocalls_cpuslocked()
Date: Thu, 20 Apr 2017 09:32:11 -0600	[thread overview]
Message-ID: <20170420153211.GA11868@linaro.org> (raw)
In-Reply-To: <20170418170553.026838125@linutronix.de>

On Tue, Apr 18, 2017 at 07:04:50PM +0200, Thomas Gleixner wrote:
> From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> 
> etm_probe() holds get_online_cpus() while invoking
> cpuhp_setup_state_nocalls().
> 
> cpuhp_setup_state_nocalls() invokes get_online_cpus() as well. This is
> correct, but prevents the conversion of the hotplug locking to a percpu
> rwsem.
> 
> Use cpuhp_setup_state_nocalls_cpuslocked() to avoid the nested call.
> 
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> Cc: linux-arm-kernel@lists.infradead.org
> 
> ---
>  drivers/hwtracing/coresight/coresight-etm3x.c |   12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> --- a/drivers/hwtracing/coresight/coresight-etm3x.c
> +++ b/drivers/hwtracing/coresight/coresight-etm3x.c
> @@ -803,12 +803,12 @@ static int etm_probe(struct amba_device
>  		dev_err(dev, "ETM arch init failed\n");
>  
>  	if (!etm_count++) {
> -		cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING,
> -					  "arm/coresight:starting",
> -					  etm_starting_cpu, etm_dying_cpu);
> -		ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
> -						"arm/coresight:online",
> -						etm_online_cpu, NULL);
> +		cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ARM_CORESIGHT_STARTING,
> +						     "arm/coresight:starting",
> +						     etm_starting_cpu, etm_dying_cpu);
> +		ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,
> +							   "arm/coresight:online",
> +							   etm_online_cpu, NULL);

Checkpatch complains about lines being over 80 characters long.  It is better to
keep the above or do as follow and make checkpatch happy?

                cpuhp_setup_state_nocalls_cpuslocked(
                                        PUHP_AP_ARM_CORESIGHT_STARTING,
                                        "arm/coresight:starting",
                                        etm_starting_cpu, etm_dying_cpu);
                ret = cpuhp_setup_state_nocalls_cpuslocked(
                                        CPUHP_AP_ONLINE_DYN,
                                        "arm/coresight:online",
                                        etm_online_cpu, NULL);

Same for coresight-etm4x.c

Thanks,
Mathieu

  parent reply	other threads:[~2017-04-20 15:32 UTC|newest]

Thread overview: 72+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-18 17:04 [patch V2 00/24] cpu/hotplug: Convert get_online_cpus() to a percpu_rwsem Thomas Gleixner
2017-04-18 17:04 ` [patch V2 01/24] cpu/hotplug: Provide cpuhp_setup/remove_state[_nocalls]_cpuslocked() Thomas Gleixner
2017-04-20 11:18   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 02/24] stop_machine: Provide stop_machine_cpuslocked() Thomas Gleixner
2017-04-20 11:19   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 03/24] padata: Make padata_alloc() static Thomas Gleixner
2017-04-20 11:19   ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2017-04-18 17:04 ` [patch V2 04/24] padata: Avoid nested calls to get_online_cpus() in pcrypt_init_padata() Thomas Gleixner
2017-04-20 11:20   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 05/24] x86/mtrr: Remove get_online_cpus() from mtrr_save_state() Thomas Gleixner
2017-04-20 11:20   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 06/24] cpufreq: Use cpuhp_setup_state_nocalls_cpuslocked() Thomas Gleixner
2017-04-20 11:21   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 07/24] KVM/PPC/Book3S HV: " Thomas Gleixner
2017-04-20 11:21   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 08/24] hwtracing/coresight-etm3x: " Thomas Gleixner
2017-04-20 11:22   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-20 15:14   ` [patch V2 08/24] " Mathieu Poirier
2017-04-20 15:32   ` Mathieu Poirier [this message]
2017-04-18 17:04 ` [patch V2 09/24] hwtracing/coresight-etm4x: " Thomas Gleixner
2017-04-20 11:22   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 10/24] perf/x86/intel/cqm: Use cpuhp_setup_state_cpuslocked() Thomas Gleixner
2017-04-20 11:23   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 11/24] ARM/hw_breakpoint: " Thomas Gleixner
2017-04-19 17:54   ` Mark Rutland
2017-04-19 18:20     ` Thomas Gleixner
2017-04-20 11:23   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 12/24] s390/kernel: Use stop_machine_cpuslocked() Thomas Gleixner
2017-04-20 11:24   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 13/24] powerpc/powernv: " Thomas Gleixner
2017-04-20 11:24   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 14/24] cpu/hotplug: Use stop_machine_cpuslocked() in takedown_cpu() Thomas Gleixner
2017-04-20 11:25   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 15/24] x86/perf: Drop EXPORT of perf_check_microcode Thomas Gleixner
2017-04-20 11:25   ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2017-04-18 17:04 ` [patch V2 16/24] perf/x86/intel: Drop get_online_cpus() in intel_snb_check_microcode() Thomas Gleixner
2017-04-20 11:26   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 17/24] PCI: Use cpu_hotplug_disable() instead of get_online_cpus() Thomas Gleixner
2017-04-20 11:27   ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2017-04-18 17:05 ` [patch V2 18/24] PCI: Replace the racy recursion prevention Thomas Gleixner
2017-04-20 11:27   ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2017-04-18 17:05 ` [patch V2 19/24] ACPI/processor: Use cpu_hotplug_disable() instead of get_online_cpus() Thomas Gleixner
2017-04-20 11:28   ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2017-04-18 17:05 ` [patch V2 20/24] perf/core: Remove redundant get_online_cpus() Thomas Gleixner
2017-04-20 11:28   ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2017-04-18 17:05 ` [patch V2 21/24] jump_label: Pull get_online_cpus() into generic code Thomas Gleixner
2017-04-18 17:05 ` [patch V2 22/24] jump_label: Provide static_key_slow_inc_cpuslocked() Thomas Gleixner
2017-04-18 17:05 ` [patch V2 23/24] perf: Avoid cpu_hotplug_lock r-r recursion Thomas Gleixner
2017-04-18 17:05 ` [patch V2 24/24] cpu/hotplug: Convert hotplug locking to percpu rwsem Thomas Gleixner
2017-04-20 11:30   ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2017-05-10  4:59   ` [patch V2 24/24] " Michael Ellerman
2017-05-10  8:49     ` Thomas Gleixner
2017-05-10 16:30       ` Steven Rostedt
2017-05-10 17:15         ` Steven Rostedt
2017-05-11  5:49       ` Michael Ellerman
2017-04-25 16:10 ` [patch V2 00/24] cpu/hotplug: Convert get_online_cpus() to a percpu_rwsem Mark Rutland
2017-04-25 17:28   ` Sebastian Siewior
2017-04-26  8:59     ` Mark Rutland
2017-04-26  9:40       ` Suzuki K Poulose
2017-04-26 10:32         ` Mark Rutland
2017-04-27  8:27           ` Sebastian Siewior
2017-04-27  9:57             ` Mark Rutland
2017-04-27 10:01               ` Thomas Gleixner
2017-04-27 12:30                 ` Mark Rutland
2017-04-27 15:48                   ` [PATCH] arm64: cpufeature: use static_branch_enable_cpuslocked() (was: Re: [patch V2 00/24] cpu/hotplug: Convert get_online_cpus() to a percpu_rwsem) Mark Rutland
2017-04-27 16:35                     ` Suzuki K Poulose
2017-04-27 17:03                       ` [PATCH] arm64: cpufeature: use static_branch_enable_cpuslocked() Suzuki K Poulose
2017-04-27 17:17                         ` Mark Rutland
2017-04-28 14:24 ` [RFC PATCH] trace/perf: cure locking issue in perf_event_open() error path Sebastian Siewior
2017-04-28 14:27   ` Sebastian Siewior
2017-05-01 12:57   ` [tip:smp/hotplug] perf: Reorder cpu hotplug rwsem against cred_guard_mutex tip-bot for Thomas Gleixner
2017-05-01 12:58   ` [tip:smp/hotplug] perf: Push hotplug protection down to callers tip-bot for Thomas Gleixner

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