Re: [dpdk-dev] [PATCH v2 2/2] test/service: fix race condition on stopping lcore

[Phil Yang <Phil.Yang@arm.com>]

<...>

> Subject: [dpdk-dev] [PATCH v2 2/2] test/service: fix race condition on
> stopping lcore
> 
> This commit fixes a potential race condition in the tests
> where the lcore running a service would increment a counter
> that was already reset by the test-suite thread. The resulting
> race-condition incremented value could cause CI failures, as
> indicated by DPDK's CI.
> 
> This patch fixes the race-condition by making use of the
> added rte_service_lcore_active() API, which indicates when
> a service-core is no longer in the service-core polling loop.
> 
> The unit test makes use of the above function to detect when
> all statistics increments are done in the service-core thread,
> and then the unit test continues finalizing and checking state.
> 
> Fixes: f28f3594ded2 ("service: add attribute API")
> 
> Reported-by: David Marchand <david.marchand@redhat.com>
> Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com>

Minor nit, otherwise it looks good to me.

Reviewed-by: Phil Yang <phil.yang@arm.com>

> 
> ---
> 
> Thanks for discussion on v1, this v2 fixup for the CI
> including previous feedback on ML.
> ---
>  app/test/test_service_cores.c | 22 +++++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/app/test/test_service_cores.c b/app/test/test_service_cores.c
> index ef1d8fcb9..a45762915 100644
> --- a/app/test/test_service_cores.c
> +++ b/app/test/test_service_cores.c
> @@ -362,6 +362,9 @@ service_lcore_attr_get(void)
>  			"Service core add did not return zero");
>  	TEST_ASSERT_EQUAL(0, rte_service_map_lcore_set(id, slcore_id, 1),
>  			"Enabling valid service and core failed");
> +	/* Ensure service is not active before starting */
> +	TEST_ASSERT_EQUAL(0, rte_service_lcore_active(slcore_id),
> +			"Not-active service core reported as active");
>  	TEST_ASSERT_EQUAL(0, rte_service_lcore_start(slcore_id),
>  			"Starting service core failed");
> 
> @@ -382,7 +385,24 @@ service_lcore_attr_get(void)
>  			lcore_attr_id, &lcore_attr_value),
>  			"Invalid lcore attr didn't return -EINVAL");
> 
> -	rte_service_lcore_stop(slcore_id);
> +	/* Ensure service is active */
> +	TEST_ASSERT_EQUAL(1, rte_service_lcore_active(slcore_id),
> +			"Active service core reported as not-active");
> +
> +	TEST_ASSERT_EQUAL(0, rte_service_map_lcore_set(id, slcore_id, 0),
> +			"Disabling valid service and core failed");
> +	TEST_ASSERT_EQUAL(0, rte_service_lcore_stop(slcore_id),
> +			"Failed to stop service lcore");
> +
> +	int i = 0;
> +	while (rte_service_lcore_active(slcore_id) == 1) {
> +		rte_delay_ms(1);

Just as it does in other functions, use the macro instead of the magic number would be better.
rte_delay_ms(SERVICE_DELAY); 

> +		i++;
> +		if (i > 100)
> +			break;
> +	}
> +	TEST_ASSERT_EQUAL(0, rte_service_lcore_active(slcore_id),
> +			  "Service lcore not stopped after waiting.");
> 
>  	TEST_ASSERT_EQUAL(0, rte_service_lcore_attr_reset_all(slcore_id),
>  			  "Valid lcore_attr_reset_all() didn't return success");
> --
> 2.17.1