From: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
To: ego@linux.vnet.ibm.com
Cc: mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org,
Hemant Kumar <hemant@linux.vnet.ibm.com>,
Balbir Singh <bsingharora@gmail.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Anton Blanchard <anton@samba.org>,
Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>,
Michael Neuling <mikey@neuling.org>,
Stewart Smith <stewart@linux.vnet.ibm.com>,
Daniel Axtens <dja@axtens.net>,
Stephane Eranian <eranian@google.com>,
Anju T Sudhakar <anju@linux.vnet.ibm.com>
Subject: Re: [PATCH v5 08/13] powerpc/perf: PMU functions for Core IMC and hotplugging
Date: Tue, 28 Mar 2017 10:11:51 +0530 [thread overview]
Message-ID: <5aaf098d-5919-e7c6-b4a6-0acbb5baa222@linux.vnet.ibm.com> (raw)
In-Reply-To: <20170323130947.GB4897@in.ibm.com>
On Thursday 23 March 2017 06:39 PM, Gautham R Shenoy wrote:
> Hi Maddy, Hemant, Anju,
>
> On Thu, Mar 16, 2017 at 01:05:02PM +0530, Madhavan Srinivasan wrote:
>
> [..snip..]
>
>> +
>> +static void core_imc_change_cpu_context(int old_cpu, int new_cpu)
>> +{
>> + if (!core_imc_pmu)
>> + return;
>> + perf_pmu_migrate_context(&core_imc_pmu->pmu, old_cpu, new_cpu);
>> +}
>> +
>> +
>> +static int ppc_core_imc_cpu_online(unsigned int cpu)
>> +{
>> + int ret;
>> +
>> + /* If a cpu for this core is already set, then, don't do anything */
>> + ret = cpumask_any_and(&core_imc_cpumask,
>> + cpu_sibling_mask(cpu));
>> + if (ret < nr_cpu_ids)
>> + return 0;
>> +
>> + /* Else, set the cpu in the mask, and change the context */
>> + cpumask_set_cpu(cpu, &core_imc_cpumask);
>> + core_imc_change_cpu_context(-1, cpu);
> So, in the core case, we are ok as long as any cpu in the core is
> present in the imc_cpumask. It need not have to be the smallest online
> cpu in the core.
>
> Can the same logic be applied to the earlier nest case ?
Yes. This makes sense. Let me look at this.
Thanks for review
Maddy
>
> We can have a single function for cpu_offline and cpu_online which
> implements these checks and sets the cpu bit if required.
>
> ppc_entity_imc_cpu_offline(unsigned int cpu, cpumask_t
> entity_imc_mask,
> entity_imc_change_cpu_context_fn)
> {
> .
> .
> .
>
> }
>
>
> static ppc_nest_imc_cpu_offline(unsigned int cpu)
> {
> return ppc_entity_imc_cpu_offline(cpu, nest_imc_mask,
> nest_imc_change_cpu_context);
> }
>
> And similar ones for core imc and thread imc.
>
> Does this sound reasonable ?
>> + return 0;
>> +}
>> +
>> +static int ppc_core_imc_cpu_offline(unsigned int cpu)
>> +{
>> + int target;
>> + unsigned int ncpu;
>> +
>> + /*
>> + * clear this cpu out of the mask, if not present in the mask,
>> + * don't bother doing anything.
>> + */
>> + if (!cpumask_test_and_clear_cpu(cpu, &core_imc_cpumask))
>> + return 0;
>> +
>> + /* Find any online cpu in that core except the current "cpu" */
>> + ncpu = cpumask_any_but(cpu_sibling_mask(cpu), cpu);
>> +
>> + if (ncpu < nr_cpu_ids) {
>> + target = ncpu;
>> + cpumask_set_cpu(target, &core_imc_cpumask);
>> + } else
>> + target = -1;
>> +
>> + /* migrate the context */
>> + core_imc_change_cpu_context(cpu, target);
>> +
>> + return 0;
>> +}
>> +
> --
> Thanks and Regards
> gautham.
next prev parent reply other threads:[~2017-03-28 4:43 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-16 7:34 [PATCH v5 00/13] IMC Instrumentation Support Madhavan Srinivasan
2017-03-16 7:34 ` [PATCH v5 01/13] powerpc/powernv: Data structure and macros definitions Madhavan Srinivasan
2017-03-16 7:34 ` [PATCH v5 02/13] powerpc/powernv: Autoload IMC device driver module Madhavan Srinivasan
2017-03-16 7:34 ` [PATCH v5 03/13] powerpc/powernv: Detect supported IMC units and its events Madhavan Srinivasan
2017-03-16 7:34 ` [PATCH v5 04/13] powerpc/perf: Add event attribute and group to IMC pmus Madhavan Srinivasan
2017-03-16 7:34 ` [PATCH v5 05/13] powerpc/perf: Generic imc pmu event functions Madhavan Srinivasan
2017-03-16 7:35 ` [PATCH v5 06/13] powerpc/perf: IMC pmu cpumask and cpu hotplug support Madhavan Srinivasan
2017-03-23 11:52 ` Gautham R Shenoy
2017-03-27 10:34 ` Anju T Sudhakar
2017-03-16 7:35 ` [PATCH v5 07/13] powerpc/powernv: Core IMC events detection Madhavan Srinivasan
2017-03-16 7:35 ` [PATCH v5 08/13] powerpc/perf: PMU functions for Core IMC and hotplugging Madhavan Srinivasan
2017-03-23 13:09 ` Gautham R Shenoy
2017-03-28 4:41 ` Madhavan Srinivasan [this message]
2017-03-16 7:35 ` [PATCH v5 09/13] powerpc/powernv: Thread IMC events detection Madhavan Srinivasan
2017-03-16 7:35 ` [PATCH v5 10/13] powerpc/perf: Thread IMC PMU functions Madhavan Srinivasan
2017-03-16 7:35 ` [PATCH 11/13] powerpc/powernv: Add device shutdown function for Core IMC Madhavan Srinivasan
2017-03-16 7:35 ` [PATCH 12/13] powerpc/perf: Thread imc cpuhotplug support Madhavan Srinivasan
2017-03-23 17:15 ` Gautham R Shenoy
2017-03-27 10:35 ` Anju T Sudhakar
2017-03-16 7:35 ` [PATCH 13/13] powerpc/perf: Enable/disable core engine during cpuhotplug Madhavan Srinivasan
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