Re: [dpdk-dev] [PATCH] test/service: add perf test for service on app lcore

["Van Haaren, Harry" <harry.van.haaren@intel.com>]

> -----Original Message-----
> From: David Marchand <david.marchand@redhat.com>
> Sent: Wednesday, May 6, 2020 4:44 PM
> To: Van Haaren, Harry <harry.van.haaren@intel.com>
> Cc: dev <dev@dpdk.org>; Honnappa Nagarahalli
> <honnappa.nagarahalli@arm.com>; Phil Yang <phil.yang@arm.com>
> Subject: Re: [dpdk-dev] [PATCH] test/service: add perf test for service on app
<snip>
> > +       /* Performance test: call in a loop, and measure tsc() */
> > +       const uint32_t perf_iters = (1 << 12);
> > +       uint64_t start = rte_rdtsc();
> > +       for (uint32_t i = 0; i < perf_iters; i++) {
> 
> - How long does this test take now?
> We tend to put performance tests in dedicated tests to avoid issues in Travis.
> I suppose this is quick, but still want a confirmation.

Can confirm this is quick, blink of an eye quick, maybe ~250k cycles.


> - Centos7/RHEL7 gcc is not happy with this.
> 
> http://mails.dpdk.org/archives/test-report/2020-May/129993.html
> 
> ../app/test/test_service_cores.c: In function ‘service_app_lcore_poll_impl’:
> ../app/test/test_service_cores.c:795:2: error: ‘for’ loop initial
> declarations are only allowed in C99 mode
>   for (uint32_t i = 0; i < perf_iters; i++) {
>   ^
> ../app/test/test_service_cores.c:795:2: note: use option -std=c99 or
> -std=gnu99 to compile your code

Will fix in v2.


> > +               int err = service_run_on_app_core_func(&id);
> > +               TEST_ASSERT_EQUAL(0, err, "perf test: returned run failure");
> > +       }
> > +       uint64_t end = rte_rdtsc();
> > +       printf("perf test for %s: %0.1f cycles per call\n", mt_safe ?
> > +               "MT Safe" : "MT Unsafe", (end - start)/(float)perf_iters);
> >
> > +       unregister_all();
> >         return TEST_SUCCESS;
> >  }
> >
> 
> - Can you look at Phil comments too?

Yes - will update to use padding at start of line in output.

V2 on the way.