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

[Lukasz Wojciechowski <l.wojciechow@partner.samsung.com>]

W dniu 20.07.2020 o 16:38, Harry van Haaren pisze:
> 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>
>
> ---
>
> 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);
> +		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");
Acked-by: Lukasz Wojciechowski <l.wojciechow@partner.samsung.com>

-- 
Lukasz Wojciechowski
Principal Software Engineer

Samsung R&D Institute Poland
Samsung Electronics
Office +48 22 377 88 25
l.wojciechow@partner.samsung.com