Re: [PATCH v2 1/2] powerpc/perf/hv-24x7: Add cpu hotplug support
On 6/24/20 4:06 PM, Gautham R Shenoy wrote:
> On Wed, Jun 24, 2020 at 03:47:53PM +0530, Kajol Jain wrote:
>> Patch here adds cpu hotplug functions to hv_24x7 pmu.
>> A new cpuhp_state "CPUHP_AP_PERF_POWERPC_HV_24x7_ONLINE" enum
>> is added.
>>
>> The online function update the cpumask only if its NULL.
> ^^ ^
> online callback function updates it is empty.
>
>
>> As the primary intention for adding hotplug support
>> is to desiginate a CPU to make HCALL to collect the
> ^^
> designate
>
Sorry My bad. Thanks for reviewing the patch. Will correct these
mistakes.
Thanks,
Kajol Jain
>> count data.
>>
>> The offline function test and clear corresponding cpu in a cpumask
>> and update cpumask to any other active cpu.
>>
>> Signed-off-by: Kajol Jain
>
> Otherwise, looks good to me.
>
> Reviewed-by: Gautham R. Shenoy
>
>> ---
>> arch/powerpc/perf/hv-24x7.c | 45 +
>> include/linux/cpuhotplug.h | 1 +
>> 2 files changed, 46 insertions(+)
>>
>> diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c
>> index db213eb7cb02..ce4739e2b407 100644
>> --- a/arch/powerpc/perf/hv-24x7.c
>> +++ b/arch/powerpc/perf/hv-24x7.c
>> @@ -31,6 +31,8 @@ static int interface_version;
>> /* Whether we have to aggregate result data for some domains. */
>> static bool aggregate_result_elements;
>>
>> +static cpumask_t hv_24x7_cpumask;
>> +
>> static bool domain_is_valid(unsigned domain)
>> {
>> switch (domain) {
>> @@ -1641,6 +1643,44 @@ static struct pmu h_24x7_pmu = {
>> .capabilities = PERF_PMU_CAP_NO_EXCLUDE,
>> };
>>
>> +static int ppc_hv_24x7_cpu_online(unsigned int cpu)
>> +{
>> +/* Make this CPU the designated target for counter collection */
>> +if (cpumask_empty(_24x7_cpumask))
>> +cpumask_set_cpu(cpu, _24x7_cpumask);
>> +
>> +return 0;
>> +}
>> +
>> +static int ppc_hv_24x7_cpu_offline(unsigned int cpu)
>> +{
>> +int target = -1;
>> +
>> +/* Check if exiting cpu is used for collecting 24x7 events */
>> +if (!cpumask_test_and_clear_cpu(cpu, _24x7_cpumask))
>> +return 0;
>> +
>> +/* Find a new cpu to collect 24x7 events */
>> +target = cpumask_last(cpu_active_mask);
>> +
>> +if (target < 0 || target >= nr_cpu_ids)
>> +return -1;
>> +
>> +/* Migrate 24x7 events to the new target */
>> +cpumask_set_cpu(target, _24x7_cpumask);
>> +perf_pmu_migrate_context(_24x7_pmu, cpu, target);
>> +
>> +return 0;
>> +}
>> +
>> +static int hv_24x7_cpu_hotplug_init(void)
>> +{
>> +return cpuhp_setup_state(CPUHP_AP_PERF_POWERPC_HV_24x7_ONLINE,
>> + "perf/powerpc/hv_24x7:online",
>> + ppc_hv_24x7_cpu_online,
>> + ppc_hv_24x7_cpu_offline);
>> +}
>> +
>> static int hv_24x7_init(void)
>> {
>> int r;
>> @@ -1685,6 +1725,11 @@ static int hv_24x7_init(void)
>> if (r)
>> return r;
>>
>> +/* init cpuhotplug */
>> +r = hv_24x7_cpu_hotplug_init();
>> +if (r)
>> +pr_err("hv_24x7: CPU hotplug init failed\n");
>> +
>> r = perf_pmu_register(_24x7_pmu, h_24x7_pmu.name, -1);
>> if (r)
>> return r;
>> diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
>> index 191772d4a4d7..a2710e654b64 100644
>> --- a/include/linux/cpuhotplug.h
>> +++ b/include/linux/cpuhotplug.h
>> @@ -181,6 +181,7 @@ enum cpuhp_state {
>> CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE,
>> CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE,
>> CPUHP_AP_PERF_POWERPC_TRACE_IMC_ONLINE,
>> +CPUHP_AP_PERF_POWERPC_HV_24x7_ONLINE,
>> CPUHP_AP_WATCHDOG_ONLINE,
>> CPUHP_AP_WORKQUEUE_ONLINE,
>> CPUHP_AP_RCUTREE_ONLINE,
>> --
>> 2.18.2
>>
Re: [PATCH v2 1/2] powerpc/perf/hv-24x7: Add cpu hotplug support
On Wed, Jun 24, 2020 at 03:47:53PM +0530, Kajol Jain wrote:
> Patch here adds cpu hotplug functions to hv_24x7 pmu.
> A new cpuhp_state "CPUHP_AP_PERF_POWERPC_HV_24x7_ONLINE" enum
> is added.
>
> The online function update the cpumask only if its NULL.
^^ ^
online callback function updates it is empty.
> As the primary intention for adding hotplug support
> is to desiginate a CPU to make HCALL to collect the
^^
designate
> count data.
>
> The offline function test and clear corresponding cpu in a cpumask
> and update cpumask to any other active cpu.
>
> Signed-off-by: Kajol Jain
Otherwise, looks good to me.
Reviewed-by: Gautham R. Shenoy
> ---
> arch/powerpc/perf/hv-24x7.c | 45 +
> include/linux/cpuhotplug.h | 1 +
> 2 files changed, 46 insertions(+)
>
> diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c
> index db213eb7cb02..ce4739e2b407 100644
> --- a/arch/powerpc/perf/hv-24x7.c
> +++ b/arch/powerpc/perf/hv-24x7.c
> @@ -31,6 +31,8 @@ static int interface_version;
> /* Whether we have to aggregate result data for some domains. */
> static bool aggregate_result_elements;
>
> +static cpumask_t hv_24x7_cpumask;
> +
> static bool domain_is_valid(unsigned domain)
> {
> switch (domain) {
> @@ -1641,6 +1643,44 @@ static struct pmu h_24x7_pmu = {
> .capabilities = PERF_PMU_CAP_NO_EXCLUDE,
> };
>
> +static int ppc_hv_24x7_cpu_online(unsigned int cpu)
> +{
> + /* Make this CPU the designated target for counter collection */
> + if (cpumask_empty(_24x7_cpumask))
> + cpumask_set_cpu(cpu, _24x7_cpumask);
> +
> + return 0;
> +}
> +
> +static int ppc_hv_24x7_cpu_offline(unsigned int cpu)
> +{
> + int target = -1;
> +
> + /* Check if exiting cpu is used for collecting 24x7 events */
> + if (!cpumask_test_and_clear_cpu(cpu, _24x7_cpumask))
> + return 0;
> +
> + /* Find a new cpu to collect 24x7 events */
> + target = cpumask_last(cpu_active_mask);
> +
> + if (target < 0 || target >= nr_cpu_ids)
> + return -1;
> +
> + /* Migrate 24x7 events to the new target */
> + cpumask_set_cpu(target, _24x7_cpumask);
> + perf_pmu_migrate_context(_24x7_pmu, cpu, target);
> +
> + return 0;
> +}
> +
> +static int hv_24x7_cpu_hotplug_init(void)
> +{
> + return cpuhp_setup_state(CPUHP_AP_PERF_POWERPC_HV_24x7_ONLINE,
> + "perf/powerpc/hv_24x7:online",
> + ppc_hv_24x7_cpu_online,
> + ppc_hv_24x7_cpu_offline);
> +}
> +
> static int hv_24x7_init(void)
> {
> int r;
> @@ -1685,6 +1725,11 @@ static int hv_24x7_init(void)
> if (r)
> return r;
>
> + /* init cpuhotplug */
> + r = hv_24x7_cpu_hotplug_init();
> + if (r)
> + pr_err("hv_24x7: CPU hotplug init failed\n");
> +
> r = perf_pmu_register(_24x7_pmu, h_24x7_pmu.name, -1);
> if (r)
> return r;
> diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
> index 191772d4a4d7..a2710e654b64 100644
> --- a/include/linux/cpuhotplug.h
> +++ b/include/linux/cpuhotplug.h
> @@ -181,6 +181,7 @@ enum cpuhp_state {
> CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE,
> CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE,
> CPUHP_AP_PERF_POWERPC_TRACE_IMC_ONLINE,
> + CPUHP_AP_PERF_POWERPC_HV_24x7_ONLINE,
> CPUHP_AP_WATCHDOG_ONLINE,
> CPUHP_AP_WORKQUEUE_ONLINE,
> CPUHP_AP_RCUTREE_ONLINE,
> --
> 2.18.2
>
