Commit 0464b1ed authored by Maciej Fijalkowski's avatar Maciej Fijalkowski Committed by Alexei Starovoitov
Browse files

selftests: xsk: Remove sync_mutex_tx and atomic var 



Although thread_common_ops() are called in both Tx and Rx threads,
testapp_validate() will not spawn Tx thread until Rx thread signals that
it has finished its initialization via condition variable.

Therefore, locking in thread_common_ops is not needed and furthermore Tx
thread does not have to spin on atomic variable.

Note that this simplification wouldn't be possible if there would still
be a common worker thread.

Signed-off-by: default avatarMaciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210329224316.17793-13-maciej.fijalkowski@intel.com
parent 9445f8c7

tools/testing/selftests/bpf/xdpxceiver.c

+7 −24
Original line number Diff line number Diff line
@@ -121,17 +121,15 @@ static void __exit_with_error(int error, const char *file, const char *func, int 
			       test_type == TEST_TYPE_BIDI ? "Bi-directional Sockets" : "",\

			       test_type == TEST_TYPE_STATS ? "Stats" : ""))



static void pthread_init_mutex(void)

static void init_sync_resources(void)

{

	pthread_mutex_init(&sync_mutex, NULL);

	pthread_mutex_init(&sync_mutex_tx, NULL);

	pthread_cond_init(&signal_rx_condition, NULL);

}



static void pthread_destroy_mutex(void)

static void destroy_sync_resources(void)

{

	pthread_mutex_destroy(&sync_mutex);

	pthread_mutex_destroy(&sync_mutex_tx);

	pthread_cond_destroy(&signal_rx_condition);

}
@@ -752,7 +750,7 @@ static void worker_pkt_validate(void) 
	}

}



static void thread_common_ops(struct ifobject *ifobject, void *bufs, pthread_mutex_t *mutexptr)

static void thread_common_ops(struct ifobject *ifobject, void *bufs)

{

	int ctr = 0;

	int ret;
@@ -771,22 +769,13 @@ static void thread_common_ops(struct ifobject *ifobject, void *bufs, pthread_mut 


	/* Retry Create Socket if it fails as xsk_socket__create()

	 * is asynchronous

	 *

	 * Essential to lock Mutex here to prevent Tx thread from

	 * entering before Rx and causing a deadlock

	 */

	pthread_mutex_lock(mutexptr);

	while (ret && ctr < SOCK_RECONF_CTR) {

		if (ifobject->fv.vector == rx)

			atomic_store(&spinning_rx, 1);

		xsk_configure_umem(ifobject, bufs, num_frames * XSK_UMEM__DEFAULT_FRAME_SIZE);

		ret = xsk_configure_socket(ifobject);

		usleep(USLEEP_MAX);

		ctr++;

	}

	if (ifobject->fv.vector == rx)

		atomic_store(&spinning_rx, 0);

	pthread_mutex_unlock(mutexptr);



	if (ctr >= SOCK_RECONF_CTR)

		exit_with_error(ret);
@@ -803,16 +792,10 @@ static void *worker_testapp_validate_tx(void *arg) 
	struct ethhdr *eth_hdr = (struct ethhdr *)pkt_data;

	struct ifobject *ifobject = (struct ifobject *)arg;

	struct generic_data data;

	int spinningrxctr = 0;

	void *bufs = NULL;



	if (!bidi_pass)

		thread_common_ops(ifobject, bufs, &sync_mutex_tx);



	while (atomic_load(&spinning_rx) && spinningrxctr < SOCK_RECONF_CTR) {

		spinningrxctr++;

		usleep(USLEEP_MAX);

	}

		thread_common_ops(ifobject, bufs);



	for (int i = 0; i < num_frames; i++) {

		/*send EOT frame */
@@ -845,7 +828,7 @@ static void *worker_testapp_validate_rx(void *arg) 
	void *bufs = NULL;



	if (!bidi_pass)

		thread_common_ops(ifobject, bufs, &sync_mutex_tx);

		thread_common_ops(ifobject, bufs);



	if (stat_test_type != STAT_TEST_RX_FILL_EMPTY)

		xsk_populate_fill_ring(ifobject->umem);
@@ -1103,7 +1086,7 @@ int main(int argc, char **argv) 


	ksft_set_plan(TEST_MODE_MAX * TEST_TYPE_MAX);



	pthread_init_mutex();

	init_sync_resources();



	for (i = 0; i < TEST_MODE_MAX; i++) {

		for (j = 0; j < TEST_TYPE_MAX; j++)
@@ -1116,7 +1099,7 @@ int main(int argc, char **argv) 
		free(ifdict[i]);

	}



	pthread_destroy_mutex();

	destroy_sync_resources();



	ksft_exit_pass();

tools/testing/selftests/bpf/xdpxceiver.h

+0 −2
Original line number Diff line number Diff line
@@ -146,9 +146,7 @@ static struct ifobject *ifdict_rx; 
static struct ifobject *ifdict_tx;



/*threads*/

atomic_int spinning_rx;

pthread_mutex_t sync_mutex;

pthread_mutex_t sync_mutex_tx;

pthread_cond_t signal_rx_condition;

pthread_t t0, t1;

pthread_attr_t attr;