Re: [PATCH v1 2/3] test: add test case for read write concurrency

["De Lara Guarch, Pablo" <pablo.de.lara.guarch@intel.com>]

Hi Yipeng,

> -----Original Message-----
> From: Wang, Yipeng1
> Sent: Friday, June 8, 2018 11:51 AM
> To: De Lara Guarch, Pablo <pablo.de.lara.guarch@intel.com>
> Cc: dev@dpdk.org; Wang, Yipeng1 <yipeng1.wang@intel.com>; Mcnamara,
> John <john.mcnamara@intel.com>; Richardson, Bruce
> <bruce.richardson@intel.com>; honnappa.nagarahalli@arm.com;
> vguvva@caviumnetworks.com; brijesh.s.singh@gmail.com
> Subject: [PATCH v1 2/3] test: add test case for read write concurrency
> 
> This commit adds a new test case for testing read/write concurrency.

Could you split this patch into two? One adding lock "support" in the current
performance test code and another one adding the new readwrite tests?

> 
> Signed-off-by: Yipeng Wang <yipeng1.wang@intel.com>
> ---
>  test/test/Makefile              |   1 +
>  test/test/test_hash_perf.c      |  36 ++-
>  test/test/test_hash_readwrite.c | 649

...

> +++ b/test/test/test_hash_readwrite.c

...

> +struct {
> +	uint32_t *keys;
> +	uint32_t *found;
> +	uint32_t nb_tsx_insertion;
> +	uint32_t rounded_nb_total_tsx_insertion;
> +	struct rte_hash *h;
> +} tbl_multiwriter_test_params;

I think " rounded_nb_total_tsx_insertion" and " tbl_multiwriter_test_params"
are too long, and that's why you need to split a long line into two down below.
Could you shorten these names a bit? You can change "multiwriter" to "mw",
and "rounded_nb_total_tsx_insertion" to "total_nb_tsx_inserts".

...

> +	snprintf(name, 32, "tests");
> +	hash_params.name = name;

You can set hash_params.name = "tests" directly.

> +
> +	handle = rte_hash_create(&hash_params);
> +	if (handle == NULL) {
> +		printf("hash creation failed");
> +		return -1;
> +	}

...

> +
> +err2:
> +	rte_free(keys);
> +err1:
> +	rte_hash_free(handle);

I think you can have just one label "err" with these two frees.
If the variables haven't been set, they will be NULL and that's allowed.
 
> +
> +	return -1;
> +}
> +

...

> +	begin = rte_rdtsc_precise();
> +	for (i = 0; i < read_cnt; i++) {
> +		void *data;
> +		rte_hash_lookup_data(tbl_multiwriter_test_params.h,
> +				tbl_multiwriter_test_params.keys + i,
> +				&data);
> +		if (i != (uint64_t)data) {

I see the following error and other errors when compiling with gcc 32 bits.

test/test/test_hash_readwrite.c:281:12: error:
cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
   if (i != (uint64_t)data) {
            ^

> +			printf("lookup find wrong value %d, %ld\n", i,
> +				(uint64_t)data);

...

> +
> +		if (reader_faster) {
> +			unsigned long long int cycles_per_insertion =
> +				rte_atomic64_read(&gread_cycles)/
> +				rte_atomic64_read(&greads);
> +			perf_results->read_only[n] = cycles_per_insertion;
> +			printf("Reader only: cycles per lookup: %llu\n",
> +							cycles_per_insertion);
> +		}
> +
> +		else {

} else {

...

> +		use_htm = 1;
> +		if (test_hash_readwrite_functional() < 0)
> +			return -1;
> +
> +		reader_faster = 1;

Maybe a comment about this reader_faster would be good.
Also, can we declare this variable and use_html as local and pass them to the functions,
instead of declaring them as global?


> +		if (test_hash_readwrite_perf(&htm_results) < 0)
> +			return -1;