Re: [PATCH net-next v4 4/6] selftests: net: add multithread client support to iou-zcrx

[David Wei <dw@davidwei.uk>]

On 2026-07-29 15:18, Juanlu Herrero wrote:
> Add pthreads to the iou-zcrx client so that multiple connections can be
> established simultaneously. Each client thread connects to the server
> and sends its payload independently.
> 
> Introduce the -t option to control the number of threads (default 1),
> preserving backwards compatibility with existing tests.
> 
> Assisted-by: Claude:claude-opus-4-8
> Signed-off-by: Juanlu Herrero <juanlu@fastmail.com>
> ---
>   .../testing/selftests/drivers/net/hw/Makefile |  2 +-
>   .../selftests/drivers/net/hw/iou-zcrx.c       | 38 +++++++++++++++++--
>   2 files changed, 36 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/testing/selftests/drivers/net/hw/Makefile b/tools/testing/selftests/drivers/net/hw/Makefile
> index 234db5c2c90cc..3cab3b4adbb2e 100644
> --- a/tools/testing/selftests/drivers/net/hw/Makefile
> +++ b/tools/testing/selftests/drivers/net/hw/Makefile
> @@ -88,5 +88,5 @@ include ../../../net/ynl.mk
>   include ../../../net/bpf.mk
>   
>   ifeq ($(HAS_IOURING_ZCRX),y)
> -$(OUTPUT)/iou-zcrx: LDLIBS += -luring
> +$(OUTPUT)/iou-zcrx: LDLIBS += -luring -lpthread
>   endif
> diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
> index 9b62fd0703e61..7bc61f3b70ca6 100644
> --- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
> +++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
> @@ -4,6 +4,7 @@
>   #include <error.h>
>   #include <fcntl.h>
>   #include <limits.h>
> +#include <pthread.h>
>   #include <stdbool.h>
>   #include <stdint.h>
>   #include <stdio.h>
> @@ -85,9 +86,12 @@ static int cfg_send_size = SEND_SIZE;
>   static struct sockaddr_in6 cfg_addr;
>   static unsigned int cfg_rx_buf_len;
>   static bool cfg_dry_run;
> +static int cfg_num_threads = 1;
>   
>   static char *payload;
>   
> +#define CONNS_PER_THREAD	4
> +
>   struct thread_ctx {
>   	struct io_uring		ring;
>   	void			*area_ptr;
> @@ -379,7 +383,7 @@ static void run_server(void)
>   		error(1, 0, "test failed\n");
>   }
>   
> -static void run_client(void)
> +static void *client_worker(void *arg)
>   {
>   	ssize_t to_send = cfg_send_size;
>   	ssize_t sent = 0;
> @@ -405,12 +409,37 @@ static void run_client(void)
>   	}
>   
>   	close(fd);
> +	return NULL;
> +}
> +
> +static void run_client(void)
> +{
> +	int conns_per_thread = cfg_num_threads > 1 ? CONNS_PER_THREAD : 1;

Make cfg_num_threads the default value you want, then you can remove
CONNS_PER_THREAD and this ternary.