Re: [PATCH 7/7] selftests/thermel/intel: Add test to read workload hint

["Zhang, Rui" <rui.zhang@intel.com>]

On Tue, 2023-06-20 at 16:01 -0700, Srinivas Pandruvada wrote:
> Some SoCs have in built firmware support to classify current running
> workload and pass to OS for making power management decisions.
> 
> This test program waits for notification of workload type change
> and prints. This program can be used to test this feature and also
> allows other user space programs to use as a reference.
> 
> Signed-off-by: Srinivas Pandruvada
> <srinivas.pandruvada@linux.intel.com>
> ---
>  .../testing/selftests/thermal/intel/Makefile  |  16 +++
>  .../thermal/intel/workload_hint_test.c        | 114
> ++++++++++++++++++
>  2 files changed, 130 insertions(+)
>  create mode 100644 tools/testing/selftests/thermal/intel/Makefile
>  create mode 100644
> tools/testing/selftests/thermal/intel/workload_hint_test.c
> 
> diff --git a/tools/testing/selftests/thermal/intel/Makefile
> b/tools/testing/selftests/thermal/intel/Makefile
> new file mode 100644
> index 000000000000..02459e271ef7
> --- /dev/null
> +++ b/tools/testing/selftests/thermal/intel/Makefile
> @@ -0,0 +1,16 @@
> +# SPDX-License-Identifier: GPL-2.0
> +ifndef CROSS_COMPILE
> +uname_M := $(shell uname -m 2>/dev/null || echo not)
> +ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/x86/ -e
> s/x86_64/x86/)
> +
> +ifeq ($(ARCH),x86)
> +TEST_PROGS := workload_hint_test
> +
> +all: $(TEST_PROGS)
> +
> +include ../../lib.mk
> +
> +clean:
> +       rm -fr $(TEST_PROGS)
> +endif
> +endif
> diff --git
> a/tools/testing/selftests/thermal/intel/workload_hint_test.c
> b/tools/testing/selftests/thermal/intel/workload_hint_test.c
> new file mode 100644
> index 000000000000..69a48a8ccbb4
> --- /dev/null
> +++ b/tools/testing/selftests/thermal/intel/workload_hint_test.c
> @@ -0,0 +1,114 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#define _GNU_SOURCE
> +
> +#include <stdio.h>
> +#include <string.h>
> +#include <stdlib.h>
> +#include <unistd.h>
> +#include <fcntl.h>
> +#include <poll.h>
> +
> +#define WORKLOAD_NOTIFICATION_DELAY_ATTRIBUTE
> "/sys/bus/pci/devices/0000:00:04.0/workload_hint/notification_delay_m
> s"
> +#define WORKLOAD_ENABLE_ATTRIBUTE
> "/sys/bus/pci/devices/0000:00:04.0/workload_hint/workload_hint_enable
> "
> +#define WORKLOAD_TYPE_INDEX_ATTRIBUTE 
> "/sys/bus/pci/devices/0000:00:04.0/workload_hint/workload_type_index"
> +
> +static const char * const workload_types[] = {
> +       "idle",
> +       "battery_life",
> +       "sustained",
> +       "bursty",
> +       NULL
> +};
> +
> +#define WORKLOAD_TYPE_MAX_INDEX        3
> +
> +int main(int argc, char **argv) {
> +       struct pollfd ufd;
> +       char index_str[4];
> +       int fd, ret, index;
> +       int delay = 0;
> +
> +       if (argc > 1) {
> +               char delay_str[64];
> +
> +               sscanf(argv[1], "%d", &delay);
> +               printf("Setting notification delay to %d ms\n",
> delay);
> +
> +               if (delay < 0)
> +                       exit(1);
> +
> +               sprintf(delay_str, "%s\n", argv[1]);
> +
> +               if ((fd = open(WORKLOAD_NOTIFICATION_DELAY_ATTRIBUTE,
> O_RDWR)) < 0) {
> +                       perror("Unable to open workload notification
> delay\n");
> +                       exit(1);
> +               }
> +
> +               if (write(fd, delay_str, strlen(delay_str)) < 0) {
> +                       perror("Can't set delay\n");
> +                       exit(1);
> +               }
> +
> +               close(fd);
> +
> +       }
> +
> +       /* Enable feature via sysfs knob */
> +       if ((fd = open(WORKLOAD_ENABLE_ATTRIBUTE, O_RDWR)) < 0) {
> +               perror("Unable to open workload type feature enable
> file\n");
> +               exit(1);
> +       }
> +
> +       if (write(fd, "1\n", 2) < 0) {
> +               perror("Can' enable workload hints\n");
> +               exit(1);
> +       }
> +
> +       close(fd);

This enables WORKLOAD_ENABLE_ATTRIBUTE without disabling it again.
As a test program, maybe we can add a timeout, and stop polling &
disable the WORKLOAD_ENABLE_ATTRIBUTE after the timeout?

thanks,
rui
> +
> +       while (1) {
> +               if ((fd = open(WORKLOAD_TYPE_INDEX_ATTRIBUTE,
> O_RDONLY)) < 0) {
> +                       perror("Unable to open workload type
> file\n");
> +                       exit(1);
> +               }
> +
> +               if ((lseek(fd, 0L, SEEK_SET)) < 0) {
> +                       fprintf(stderr, "Failed to set pointer to
> beginning\n");
> +                       exit(1);
> +               }
> +
> +               if (read(fd, index_str, sizeof(index_str)) < 0) {
> +                       fprintf(stderr, "Failed to read from:%s\n",
> +                       WORKLOAD_TYPE_INDEX_ATTRIBUTE);
> +                       exit(1);
> +               }
> +
> +               ufd.fd = fd;
> +               ufd.events = POLLPRI;
> +
> +               if ((ret = poll(&ufd, 1, -1)) < 0) {
> +                       perror("poll error");
> +                       exit(1);
> +               } else if (ret == 0) {
> +                       printf("Poll Timeout\n");
> +               } else {
> +                       if ((lseek(fd, 0L, SEEK_SET)) < 0) {
> +                               fprintf(stderr, "Failed to set
> pointer to beginning\n");
> +                               exit(1);
> +                       }
> +
> +                       if (read(fd, index_str, sizeof(index_str)) <
> 0) {
> +                               exit(0);
> +                       }
> +
> +                       sscanf(index_str, "%d", &index);
> +                       if (index > WORKLOAD_TYPE_MAX_INDEX)
> +                               printf("Invalid workload type
> index\n");
> +                       else
> +                               printf("workload type:%s\n",
> workload_types[index]);
> +               }
> +
> +               close(fd);
> +       }
> +}