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

[Juanlu Herrero <juanlu@fastmail.com>]

On Tue, Aug 04, 2026 at 08:47:33AM -0600, David Wei wrote:
> 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.

seems cleaner, I will fix that in v5 and thanks for the review.

Best,
Juanlu