RE: [EXTERNAL] Re: [PATCH v14 1/4] lib: add generic support for reading PMU events

[Tomasz Duszynski <tduszynski@marvell.com>]

>-----Original Message-----
>From: Stephen Hemminger <stephen@networkplumber.org>
>Sent: Friday, October 11, 2024 4:19 PM
>To: Konstantin Ananyev <konstantin.ananyev@huawei.com>
>Cc: Tomasz Duszynski <tduszynski@marvell.com>; Thomas Monjalon <thomas@monjalon.net>;
>Ruifeng.Wang@arm.com; bruce.richardson@intel.com; david.marchand@redhat.com; dev@dpdk.org; Jerin
>Jacob <jerinj@marvell.com>; konstantin.v.ananyev@yandex.ru; mattias.ronnblom@ericsson.com;
>mb@smartsharesystems.com; roretzla@linux.microsoft.com; zhoumin@loongson.cn
>Subject: [EXTERNAL] Re: [PATCH v14 1/4] lib: add generic support for reading PMU events
>
>On Fri, 11 Oct 2024 11: 56: 04 +0000 Konstantin Ananyev <konstantin. ananyev@ huawei. com> wrote: >
>> + * > > + * @return > > + * 0 in case of success, negative value otherwise. > > + */ > >
>+__rte_experimental 
>On Fri, 11 Oct 2024 11:56:04 +0000
>Konstantin Ananyev <konstantin.ananyev@huawei.com> wrote:
>
>> > + *
>> > + * @return
>> > + *   0 in case of success, negative value otherwise.
>> > + */
>> > +__rte_experimental
>> > +int
>> > +rte_pmu_init(void);
>> > +
>> > +/**
>> > + * @warning
>> > + * @b EXPERIMENTAL: this API may change without prior notice
>> > + *
>> > + * Finalize PMU library. This should be called after PMU counters are no longer being read.
>> > + */
>> > +__rte_experimental
>> > +void
>> > +rte_pmu_fini(void);
>>
>> Hmm..., why _fini_() is allowed to be called directly while _init_() doesn't?
>
>Is this handled by destructor, called from rte_eal_cleanup() and/or testpmd?

If fast tracepoint is enabled then this is called by eal_trace_fini() which is called by eal_trace_cleanup(). 

If fast tracepoint is disabled user should call it himself. Though, that counter reading works best with fast trace point because everything is handled automatically.