Re: [dpdk-dev] [PATCH v3] hash: added a new API to hash to query key id

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

> -----Original Message-----
> From: Van Haaren, Harry
> Sent: Tuesday, November 26, 2019 1:19 PM
> To: Aaron Conole <aconole@redhat.com>; Thomas Monjalon <thomas@monjalon.net>

<snip>

> > EAL: Test assert service_lcore_en_dis_able line 487 failed: Ex-service
> core
> > function call had no effect.
> >
> > So I'll spend some time in this area, it seems.
> 
> 
> The below diff makes it 100% reproducible here, failing every time.
> 
> It seems like the main thread is returning, before the service thread has
> returned.
> 
> The rte_eal_mp_wait_lcore() call seems to not wait on the service-core,
> which allows
> the main thread to read the "service_remote_launch_flag" value as 0 (before
> the service-thread writes it to 1).
> 
> Adding the delay between the service launch and service write being
> performed makes this issue much much more likely to occur - so the above
> description I have confidence in.
> 
> What I'm not clear on (yet) is why the eal_mp_wait_lcore() isn't waiting...
> 
> -H
> 
> 
> diff --git a/app/test/test_service_cores.c b/app/test/test_service_cores.c
> index 9fe38f5e0..846ad00d1 100644
> --- a/app/test/test_service_cores.c
> +++ b/app/test/test_service_cores.c
> @@ -445,6 +445,7 @@ static int
>  service_remote_launch_func(void *arg)
>  {
>         RTE_SET_USED(arg);
> +       rte_delay_ms(100);
>         service_remote_launch_flag = 1;
>         return 0;
>  }

Diff below seems to fix the problem here; Aaron would you test the below fix in your setup for a while too?
I have a loop running here attempting to reproduce - but before 100% failures and so far 100% passes with the added wait_lcore() call.


diff --git a/app/test/test_service_cores.c b/app/test/test_service_cores.c
index 9fe38f5e0..62ffedb19 100644
--- a/app/test/test_service_cores.c
+++ b/app/test/test_service_cores.c
@@ -445,6 +445,7 @@ static int
 service_remote_launch_func(void *arg)
 {
        RTE_SET_USED(arg);
+       rte_delay_ms(100);
        service_remote_launch_flag = 1;
        return 0;
 }
@@ -483,6 +484,7 @@ service_lcore_en_dis_able(void)
        int ret = rte_eal_remote_launch(service_remote_launch_func, NULL,
                                        slcore_id);
        TEST_ASSERT_EQUAL(0, ret, "Ex-service core remote launch failed.");
+       rte_eal_wait_lcore(slcore_id);
        rte_eal_mp_wait_lcore();
        TEST_ASSERT_EQUAL(1, service_remote_launch_flag,
                        "Ex-service core function call had no effect.");