Re: [dpdk-dev] [PATCH 4/4] test/lpm: avoid code duplication in rcu qsbr perf

["Medvedkin, Vladimir" <vladimir.medvedkin@intel.com>]

Hi Dharmik,

Thanks for the patches, see comments inlined


On 29/10/2020 15:36, Dharmik Thakkar wrote:
> Avoid code duplication by combining single and multi threaded tests
> 
> Signed-off-by: Dharmik Thakkar<dharmik.thakkar@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> ---
>   app/test/test_lpm_perf.c | 338 +++++++++------------------------------
>   1 file changed, 73 insertions(+), 265 deletions(-)
> 
> diff --git a/app/test/test_lpm_perf.c b/app/test/test_lpm_perf.c
> index 4f15db4f85ee..08312023b661 100644
> --- a/app/test/test_lpm_perf.c
> +++ b/app/test/test_lpm_perf.c
> @@ -430,11 +430,16 @@ test_lpm_rcu_qsbr_writer(void *arg)
>   {
>   	unsigned int i, j, si, ei;
>   	uint64_t begin, total_cycles;
> -	uint8_t core_id = (uint8_t)((uintptr_t)arg);
> +	uint8_t writer_id = (uint8_t)((uintptr_t)arg);
>   	uint32_t next_hop_add = 0xAA;
>   
> -	/* 2 writer threads are used */
> -	if (core_id % 2 == 0) {
> +	/* Single writer (writer_id = 1) */
> +	if (writer_id == 1) {

Probably it would be better to use enum here instead of 1/2/3?

> +		si = 0;
> +		ei = NUM_LDEPTH_ROUTE_ENTRIES;
> +	}
> +	/* 2 Writers (writer_id = 2/3)*/
> +	else if (writer_id == 2) {
>   		si = 0;
>   		ei = NUM_LDEPTH_ROUTE_ENTRIES / 2;
>   	} else {
> @@ -482,16 +487,17 @@ test_lpm_rcu_qsbr_writer(void *arg)
>   
>   /*
>    * Functional test:
> - * 2 writers, rest are readers
> + * 1/2 writers, rest are readers
>    */
>   static int
> -test_lpm_rcu_perf_multi_writer(void)
> +test_lpm_rcu_perf_multi_writer(uint8_t use_rcu)
>   {
>   	struct rte_lpm_config config;
>   	size_t sz;
> -	unsigned int i;
> +	unsigned int i, j;
>   	uint16_t core_id;
>   	struct rte_lpm_rcu_config rcu_cfg = {0};
> +	int (*reader_f)(void *arg) = NULL;
>   
>   	if (rte_lcore_count() < 3) {
>   		printf("Not enough cores for lpm_rcu_perf_autotest, expecting at least 3\n");
> @@ -504,273 +510,76 @@ test_lpm_rcu_perf_multi_writer(void)
>   		num_cores++;
>   	}
>   
> -	printf("\nPerf test: 2 writers, %d readers, RCU integration enabled\n",
> -		num_cores - 2);
> -
> -	/* Create LPM table */
> -	config.max_rules = NUM_LDEPTH_ROUTE_ENTRIES;
> -	config.number_tbl8s = NUM_LDEPTH_ROUTE_ENTRIES;
> -	config.flags = 0;
> -	lpm = rte_lpm_create(__func__, SOCKET_ID_ANY, &config);
> -	TEST_LPM_ASSERT(lpm != NULL);
> -
> -	/* Init RCU variable */
> -	sz = rte_rcu_qsbr_get_memsize(num_cores);
> -	rv = (struct rte_rcu_qsbr *)rte_zmalloc("rcu0", sz,
> -						RTE_CACHE_LINE_SIZE);
> -	rte_rcu_qsbr_init(rv, num_cores);
> -
> -	rcu_cfg.v = rv;
> -	/* Assign the RCU variable to LPM */
> -	if (rte_lpm_rcu_qsbr_add(lpm, &rcu_cfg) != 0) {
> -		printf("RCU variable assignment failed\n");
> -		goto error;
> -	}
> -
> -	writer_done = 0;
> -	__atomic_store_n(&gwrite_cycles, 0, __ATOMIC_RELAXED);
> -
> -	__atomic_store_n(&thr_id, 0, __ATOMIC_SEQ_CST);
> -
> -	/* Launch reader threads */
> -	for (i = 2; i < num_cores; i++)
> -		rte_eal_remote_launch(test_lpm_rcu_qsbr_reader, NULL,
> -					enabled_core_ids[i]);
> -
> -	/* Launch writer threads */
> -	for (i = 0; i < 2; i++)
> -		rte_eal_remote_launch(test_lpm_rcu_qsbr_writer,
> -					(void *)(uintptr_t)i,
> -					enabled_core_ids[i]);
> -
> -	/* Wait for writer threads */
> -	for (i = 0; i < 2; i++)
> -		if (rte_eal_wait_lcore(enabled_core_ids[i]) < 0)
> -			goto error;
> -
> -	printf("Total LPM Adds: %d\n", TOTAL_WRITES);
> -	printf("Total LPM Deletes: %d\n", TOTAL_WRITES);
> -	printf("Average LPM Add/Del: %"PRIu64" cycles\n",
> -		__atomic_load_n(&gwrite_cycles, __ATOMIC_RELAXED) / TOTAL_WRITES
> -		);
> -
> -	writer_done = 1;
> -	/* Wait until all readers have exited */
> -	for (i = 2; i < num_cores; i++)
> -		rte_eal_wait_lcore(enabled_core_ids[i]);
> -
> -	rte_lpm_free(lpm);
> -	rte_free(rv);
> -	lpm = NULL;
> -	rv = NULL;
> -
> -	/* Test without RCU integration */
> -	printf("\nPerf test: 2 writers, %d readers, RCU integration disabled\n",
> -		num_cores - 2);
> -
> -	/* Create LPM table */
> -	config.max_rules = NUM_LDEPTH_ROUTE_ENTRIES;
> -	config.number_tbl8s = NUM_LDEPTH_ROUTE_ENTRIES;
> -	config.flags = 0;
> -	lpm = rte_lpm_create(__func__, SOCKET_ID_ANY, &config);
> -	TEST_LPM_ASSERT(lpm != NULL);
> -
> -	writer_done = 0;
> -	__atomic_store_n(&gwrite_cycles, 0, __ATOMIC_RELAXED);
> -	__atomic_store_n(&thr_id, 0, __ATOMIC_SEQ_CST);
> -
> -	/* Launch reader threads */
> -	for (i = 2; i < num_cores; i++)
> -		rte_eal_remote_launch(test_lpm_reader, NULL,
> -					enabled_core_ids[i]);
> -
> -	/* Launch writer threads */
> -	for (i = 0; i < 2; i++)
> -		rte_eal_remote_launch(test_lpm_rcu_qsbr_writer,
> -					(void *)(uintptr_t)i,
> -					enabled_core_ids[i]);
> -
> -	/* Wait for writer threads */
> -	for (i = 0; i < 2; i++)
> -		if (rte_eal_wait_lcore(enabled_core_ids[i]) < 0)
> -			goto error;
> -
> -	printf("Total LPM Adds: %d\n", TOTAL_WRITES);
> -	printf("Total LPM Deletes: %d\n", TOTAL_WRITES);
> -	printf("Average LPM Add/Del: %"PRIu64" cycles\n",
> -		__atomic_load_n(&gwrite_cycles, __ATOMIC_RELAXED)
> -		/ TOTAL_WRITES);
> -
> -	writer_done = 1;
> -	/* Wait until all readers have exited */
> -	for (i = 2; i < num_cores; i++)
> -		rte_eal_wait_lcore(enabled_core_ids[i]);
> -
> -	rte_lpm_free(lpm);
> -
> -	return 0;
> -
> -error:
> -	writer_done = 1;
> -	/* Wait until all readers have exited */
> -	rte_eal_mp_wait_lcore();
> -
> -	rte_lpm_free(lpm);
> -	rte_free(rv);
> -
> -	return -1;
> -}
> -
> -/*
> - * Functional test:
> - * Single writer, rest are readers
> - */
> -static int
> -test_lpm_rcu_perf(void)
> -{
> -	struct rte_lpm_config config;
> -	uint64_t begin, total_cycles;
> -	size_t sz;
> -	unsigned int i, j;
> -	uint16_t core_id;
> -	uint32_t next_hop_add = 0xAA;
> -	struct rte_lpm_rcu_config rcu_cfg = {0};
> -
> -	if (rte_lcore_count() < 2) {
> -		printf("Not enough cores for lpm_rcu_perf_autotest, expecting at least 2\n");
> -		return TEST_SKIPPED;
> -	}
> -
> -	num_cores = 0;
> -	RTE_LCORE_FOREACH_WORKER(core_id) {
> -		enabled_core_ids[num_cores] = core_id;
> -		num_cores++;
> -	}
> -
> -	printf("\nPerf test: 1 writer, %d readers, RCU integration enabled\n",
> -		num_cores);
> -
> -	/* Create LPM table */
> -	config.max_rules = NUM_LDEPTH_ROUTE_ENTRIES;
> -	config.number_tbl8s = NUM_LDEPTH_ROUTE_ENTRIES;
> -	config.flags = 0;
> -	lpm = rte_lpm_create(__func__, SOCKET_ID_ANY, &config);
> -	TEST_LPM_ASSERT(lpm != NULL);
> -
> -	/* Init RCU variable */
> -	sz = rte_rcu_qsbr_get_memsize(num_cores);
> -	rv = (struct rte_rcu_qsbr *)rte_zmalloc("rcu0", sz,
> -						RTE_CACHE_LINE_SIZE);
> -	rte_rcu_qsbr_init(rv, num_cores);
> -
> -	rcu_cfg.v = rv;
> -	/* Assign the RCU variable to LPM */
> -	if (rte_lpm_rcu_qsbr_add(lpm, &rcu_cfg) != 0) {
> -		printf("RCU variable assignment failed\n");
> -		goto error;
> -	}
> -
> -	writer_done = 0;
> -	__atomic_store_n(&thr_id, 0, __ATOMIC_SEQ_CST);
> -
> -	/* Launch reader threads */
> -	for (i = 0; i < num_cores; i++)
> -		rte_eal_remote_launch(test_lpm_rcu_qsbr_reader, NULL,
> -					enabled_core_ids[i]);
> -
> -	/* Measure add/delete. */
> -	begin = rte_rdtsc_precise();
> -	for (i = 0; i < RCU_ITERATIONS; i++) {
> -		/* Add all the entries */
> -		for (j = 0; j < NUM_LDEPTH_ROUTE_ENTRIES; j++)
> -			if (rte_lpm_add(lpm, large_ldepth_route_table[j].ip,
> -					large_ldepth_route_table[j].depth,
> -					next_hop_add) != 0) {
> -				printf("Failed to add iteration %d, route# %d\n",
> -					i, j);
> +	for (j = 1; j < 3; j++) {
> +		if (use_rcu)
> +			printf("\nPerf test: %d writer(s), %d reader(s),"
> +			       " RCU integration enabled\n", j, num_cores - j);
> +		else
> +			printf("\nPerf test: %d writer(s), %d reader(s),"
> +			       " RCU integration disabled\n", j, num_cores - j);
> +
> +		/* Create LPM table */
> +		config.max_rules = NUM_LDEPTH_ROUTE_ENTRIES;
> +		config.number_tbl8s = NUM_LDEPTH_ROUTE_ENTRIES;
> +		config.flags = 0;
> +		lpm = rte_lpm_create(__func__, SOCKET_ID_ANY, &config);
> +		TEST_LPM_ASSERT(lpm != NULL);
> +
> +		/* Init RCU variable */
> +		if (use_rcu) {
> +			sz = rte_rcu_qsbr_get_memsize(num_cores);
> +			rv = (struct rte_rcu_qsbr *)rte_zmalloc("rcu0", sz,
> +							RTE_CACHE_LINE_SIZE);
> +			rte_rcu_qsbr_init(rv, num_cores);
> +
> +			rcu_cfg.v = rv;
> +			/* Assign the RCU variable to LPM */
> +			if (rte_lpm_rcu_qsbr_add(lpm, &rcu_cfg) != 0) {
> +				printf("RCU variable assignment failed\n");
>   				goto error;
>   			}
>   
> -		/* Delete all the entries */
> -		for (j = 0; j < NUM_LDEPTH_ROUTE_ENTRIES; j++)
> -			if (rte_lpm_delete(lpm, large_ldepth_route_table[j].ip,
> -				large_ldepth_route_table[j].depth) != 0) {
> -				printf("Failed to delete iteration %d, route# %d\n",
> -					i, j);
> -				goto error;
> -			}
> -	}
> -	total_cycles = rte_rdtsc_precise() - begin;
> +			reader_f = test_lpm_rcu_qsbr_reader;
> +		} else
> +			reader_f = test_lpm_reader;
>   
> -	printf("Total LPM Adds: %d\n", TOTAL_WRITES);
> -	printf("Total LPM Deletes: %d\n", TOTAL_WRITES);
> -	printf("Average LPM Add/Del: %g cycles\n",
> -		(double)total_cycles / TOTAL_WRITES);
> +		writer_done = 0;
> +		__atomic_store_n(&gwrite_cycles, 0, __ATOMIC_RELAXED);
>   
> -	writer_done = 1;
> -	/* Wait until all readers have exited */
> -	for (i = 0; i < num_cores; i++)
> -		if (rte_eal_wait_lcore(enabled_core_ids[i]);
> +		__atomic_store_n(&thr_id, 0, __ATOMIC_SEQ_CST);
>   
> -	rte_lpm_free(lpm);
> -	rte_free(rv);
> -	lpm = NULL;
> -	rv = NULL;
> +		/* Launch reader threads */
> +		for (i = j; i < num_cores; i++)
> +			rte_eal_remote_launch(reader_f, NULL,
> +						enabled_core_ids[i]);
>   
> -	/* Test without RCU integration */
> -	printf("\nPerf test: 1 writer, %d readers, RCU integration disabled\n",
> -		num_cores);
> +		/* Launch writer threads */
> +		for (i = 0; i < j; i++)
> +			rte_eal_remote_launch(test_lpm_rcu_qsbr_writer,

So now even single writer will acquire a lock for every _add/_delete 
operation. I don't think it is necessary.

> +						(void *)(uintptr_t)(i + j),
> +						enabled_core_ids[i]);
>   
> -	/* Create LPM table */
> -	config.max_rules = NUM_LDEPTH_ROUTE_ENTRIES;
> -	config.number_tbl8s = NUM_LDEPTH_ROUTE_ENTRIES;
> -	config.flags = 0;
> -	lpm = rte_lpm_create(__func__, SOCKET_ID_ANY, &config);
> -	TEST_LPM_ASSERT(lpm != NULL);
> -
> -	writer_done = 0;
> -	__atomic_store_n(&thr_id, 0, __ATOMIC_SEQ_CST);
> -
> -	/* Launch reader threads */
> -	for (i = 0; i < num_cores; i++)
> -		rte_eal_remote_launch(test_lpm_reader, NULL,
> -					enabled_core_ids[i]);
> -
> -	/* Measure add/delete. */
> -	begin = rte_rdtsc_precise();
> -	for (i = 0; i < RCU_ITERATIONS; i++) {
> -		/* Add all the entries */
> -		for (j = 0; j < NUM_LDEPTH_ROUTE_ENTRIES; j++)
> -			if (rte_lpm_add(lpm, large_ldepth_route_table[j].ip,
> -					large_ldepth_route_table[j].depth,
> -					next_hop_add) != 0) {
> -				printf("Failed to add iteration %d, route# %d\n",
> -					i, j);
> +		/* Wait for writer threads */
> +		for (i = 0; i < j; i++)
> +			if (rte_eal_wait_lcore(enabled_core_ids[i]) < 0)
>   				goto error;
> -			}
>   
> -		/* Delete all the entries */
> -		for (j = 0; j < NUM_LDEPTH_ROUTE_ENTRIES; j++)
> -			if (rte_lpm_delete(lpm, large_ldepth_route_table[j].ip,
> -				large_ldepth_route_table[j].depth) != 0) {
> -				printf("Failed to delete iteration %d, route# %d\n",
> -					i, j);
> -				goto error;
> -			}
> +		printf("Total LPM Adds: %d\n", TOTAL_WRITES);
> +		printf("Total LPM Deletes: %d\n", TOTAL_WRITES);
> +		printf("Average LPM Add/Del: %"PRIu64" cycles\n",
> +			__atomic_load_n(&gwrite_cycles, __ATOMIC_RELAXED)
> +			/ TOTAL_WRITES);
> +
> +		writer_done = 1;
> +		/* Wait until all readers have exited */
> +		for (i = j; i < num_cores; i++)
> +			rte_eal_wait_lcore(enabled_core_ids[i]);
> +
> +		rte_lpm_free(lpm);
> +		rte_free(rv);
> +		lpm = NULL;
> +		rv = NULL;
>   	}
> -	total_cycles = rte_rdtsc_precise() - begin;
> -
> -	printf("Total LPM Adds: %d\n", TOTAL_WRITES);
> -	printf("Total LPM Deletes: %d\n", TOTAL_WRITES);
> -	printf("Average LPM Add/Del: %g cycles\n",
> -		(double)total_cycles / TOTAL_WRITES);
> -
> -	writer_done = 1;
> -	/* Wait until all readers have exited */
> -	for (i = 0; i < num_cores; i++)
> -		rte_eal_wait_lcore(enabled_core_ids[i]);
> -
> -	rte_lpm_free(lpm);
>   
>   	return 0;
>   
> @@ -946,9 +755,8 @@ test_lpm_perf(void)
>   	rte_lpm_delete_all(lpm);
>   	rte_lpm_free(lpm);
>   
> -	test_lpm_rcu_perf();
> -
> -	test_lpm_rcu_perf_multi_writer();
> +	test_lpm_rcu_perf_multi_writer(0);
> +	test_lpm_rcu_perf_multi_writer(1);
>   
>   	return 0;
>   }
> 

-- 
Regards,
Vladimir