From: sboyd@codeaurora•org (Stephen Boyd)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCHv2 9/9] arm: perf: fold hotplug notifier into arm_pmu
Date: Mon, 27 Oct 2014 13:37:24 -0700 [thread overview]
Message-ID: <544EAD04.8040703@codeaurora.org> (raw)
In-Reply-To: <1414411599-1938-10-git-send-email-mark.rutland@arm.com>
On 10/27/2014 05:06 AM, Mark Rutland wrote:
> Handling multiple PMUs using a single hotplug notifier requires a list
> of PMUs to be maintained, with synchronisation in the probe, remove, and
> notify paths. This is error-prone and makes the code much harder to
> maintain.
>
> Instead of using a single notifier, we can dynamically allocate a
> notifier block per-PMU. The end result is the same, but the list of PMUs
> is implicit in the hotplug notifier list rather than within a perf-local
> data structure, which makes the code far easier to handle.
>
> Signed-off-by: Mark Rutland <mark.rutland@arm•com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora•org>
One nit below.
> @@ -169,6 +192,11 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
> if (!cpu_hw_events)
> return -ENOMEM;
>
> + cpu_pmu->hotplug_nb.notifier_call = cpu_pmu_notify;
> + err = register_cpu_notifier(&cpu_pmu->hotplug_nb);
> + if (err)
> + goto out_hw_events;
> +
> for_each_possible_cpu(cpu) {
> struct pmu_hw_events *events = per_cpu_ptr(cpu_hw_events, cpu);
> raw_spin_lock_init(&events->pmu_lock);
> @@ -188,38 +216,19 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
> cpu_pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
>
> return 0;
> +
> +out_hw_events:
> + free_percpu(cpu_hw_events);
> + return err;
> }
>
> static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu)
> {
> free_percpu(cpu_pmu->hw_events);
> + unregister_cpu_notifier(&cpu_pmu->hotplug_nb);
> }
>
I would expect the order to be the other way, but it probably doesn't
matter all that much on the registration error path.
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
next prev parent reply other threads:[~2014-10-27 20:37 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-27 12:06 [PATCHv2 0/9] Prepatory rework for multi-PMU support Mark Rutland
2014-10-27 12:06 ` [PATCHv2 1/9] arm: perf: factor out callchain code Mark Rutland
2014-10-27 12:06 ` [PATCHv2 2/9] arm: perf: add missing pr_info newlines Mark Rutland
2014-10-27 20:37 ` Stephen Boyd
2014-10-27 12:06 ` [PATCHv2 3/9] arm: perf: make PMU probing data-driven Mark Rutland
2014-10-27 20:37 ` Stephen Boyd
2014-10-27 12:06 ` [PATCHv2 4/9] arm: perf: use IDR types for CPU PMUs Mark Rutland
2014-10-27 12:06 ` [PATCHv2 5/9] arm: perf: limit size of accounting data Mark Rutland
2014-10-27 21:13 ` Stephen Boyd
2014-10-27 12:06 ` [PATCHv2 6/9] arm: perf: kill get_hw_events() Mark Rutland
2014-10-27 20:37 ` Stephen Boyd
2014-10-27 12:06 ` [PATCHv2 7/9] arm: perf: fold percpu_pmu into pmu_hw_events Mark Rutland
2014-10-27 12:06 ` [PATCHv2 8/9] arm: perf: dynamically allocate cpu hardware data Mark Rutland
2014-10-27 20:37 ` Stephen Boyd
2014-10-27 12:06 ` [PATCHv2 9/9] arm: perf: fold hotplug notifier into arm_pmu Mark Rutland
2014-10-27 20:37 ` Stephen Boyd [this message]
2014-10-28 14:46 ` Mark Rutland
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