[igt-dev] [PATCH i-g-t v2] lib: Add GPU power measurement

[Tvrtko Ursulin]

On 26/03/2019 09:18, Chris Wilson wrote:
> Read the RAPL power metrics courtesy of perf. Or your local HW
> equivalent?
> 
> v2: uselocale()
> v3: Use gpu_power_s(), gpu_power_J(), gpu_power_W() to try and make the
> scale factors self-consistent.
> v4: Use igt_sysfs
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>   lib/Makefile.am      |  1 +
>   lib/Makefile.sources |  2 ++
>   lib/igt_gpu_power.c  | 78 ++++++++++++++++++++++++++++++++++++++++++++
>   lib/igt_gpu_power.h  | 66 +++++++++++++++++++++++++++++++++++++
>   lib/meson.build      |  2 ++
>   5 files changed, 149 insertions(+)
>   create mode 100644 lib/igt_gpu_power.c
>   create mode 100644 lib/igt_gpu_power.h
> 
> diff --git a/lib/Makefile.am b/lib/Makefile.am
> index 3e6a7fdba..62e8bda73 100644
> --- a/lib/Makefile.am
> +++ b/lib/Makefile.am
> @@ -84,4 +84,5 @@ libintel_tools_la_LIBADD = \
>   	$(LIBUDEV_LIBS) \
>   	$(PIXMAN_LIBS) \
>   	$(GLIB_LIBS) \
> +	libigt_perf.la \
>   	-lm
> diff --git a/lib/Makefile.sources b/lib/Makefile.sources
> index cf2720981..e00347f94 100644
> --- a/lib/Makefile.sources
> +++ b/lib/Makefile.sources
> @@ -26,6 +26,8 @@ lib_source_list =	 	\
>   	igt_color_encoding.c	\
>   	igt_color_encoding.h	\
>   	igt_edid_template.h	\
> +	igt_gpu_power.c		\
> +	igt_gpu_power.h		\
>   	igt_gt.c		\
>   	igt_gt.h		\
>   	igt_gvt.c		\
> diff --git a/lib/igt_gpu_power.c b/lib/igt_gpu_power.c
> new file mode 100644
> index 000000000..61842e17e
> --- /dev/null
> +++ b/lib/igt_gpu_power.c
> @@ -0,0 +1,78 @@
> +#include <ctype.h>
> +#include <errno.h>
> +#include <fcntl.h>
> +#include <locale.h>
> +#include <math.h>
> +#include <unistd.h>
> +#include <inttypes.h>
> +
> +#include "igt_gpu_power.h"
> +#include "igt_perf.h"
> +#include "igt_sysfs.h"
> +
> +struct rapl {
> +	uint64_t power, type;
> +	double scale;
> +};
> +
> +static int rapl_parse(struct rapl *r)
> +{
> +	locale_t locale, oldlocale;
> +	int dir;
> +
> +	dir = open("/sys/devices/power", O_RDONLY);
> +	if (dir < 0)
> +		return -errno;
> +
> +	/* Replace user environment with plain C to match kernel format */
> +	locale = newlocale(LC_ALL, "C", 0);
> +	oldlocale = uselocale(locale);
> +
> +	memset(r, 0, sizeof(*r));
> +	igt_sysfs_scanf(dir, "type", "%"PRIu64, &r->type);
> +	igt_sysfs_scanf(dir, "events/energy-gpu", "event=%"PRIx64, &r->power);
> +	igt_sysfs_scanf(dir, "events/energy-gpu.scale", "%lf", &r->scale);

Check return codes?

> +
> +	uselocale(oldlocale);
> +	freelocale(locale);
> +
> +	close(dir);
> +
> +	if (isnan(r->scale) || !r->scale)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +int gpu_power_open(struct gpu_power *power)
> +{
> +	struct rapl r;
> +
> +	power->fd = rapl_parse(&r);
> +	if (power->fd < 0)
> +		goto err;
> +
> +	power->fd = igt_perf_open(r.type, r.power);
> +	if (power->fd < 0) {
> +		power->fd = -errno;
> +		goto err;
> +	}
> +
> +	power->scale = r.scale;
> +
> +	return 0;
> +
> +err:
> +	errno = 0;
> +	return power->fd;
> +}
> +
> +bool gpu_power_read(struct gpu_power *power, struct gpu_power_sample *s)
> +{
> +	return read(power->fd, s, sizeof(*s)) == sizeof(*s);
> +}
> +
> +void gpu_power_close(struct gpu_power *power)
> +{
> +	close(power->fd);
> +}
> diff --git a/lib/igt_gpu_power.h b/lib/igt_gpu_power.h
> new file mode 100644
> index 000000000..032e48b11
> --- /dev/null
> +++ b/lib/igt_gpu_power.h
> @@ -0,0 +1,66 @@
> +/*
> + * Copyright © 2019 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + *
> + */
> +
> +#ifndef IGT_GPU_POWER_H
> +#define IGT_GPU_POWER_H
> +
> +#include <stdbool.h>
> +#include <stdint.h>
> +
> +struct gpu_power {
> +	int fd;
> +	double scale;
> +};
> +
> +struct gpu_power_sample {
> +	uint64_t energy;
> +	uint64_t time;
> +};
> +
> +int gpu_power_open(struct gpu_power *power);
> +bool gpu_power_read(struct gpu_power *power, struct gpu_power_sample *s);
> +void gpu_power_close(struct gpu_power *power);
> +
> +static inline double gpu_power_J(const struct gpu_power *p,
> +				 const struct gpu_power_sample *t0,
> +				 const struct gpu_power_sample *t1)

't' makes me think of time - rename t[01] to s[01] for sample?

> +{
> +	return (t1->energy - t0->energy) * p->scale;
> +}
> +
> +static inline double gpu_power_s(const struct gpu_power *p,
> +				 const struct gpu_power_sample *t0,
> +				 const struct gpu_power_sample *t1)
> +{
> +	return (t1->time - t0->time) * 1e-9;
> +}
> +
> +static inline double gpu_power_W(const struct gpu_power *p,
> +				 const struct gpu_power_sample *t0,
> +				 const struct gpu_power_sample *t1)
> +{
> +	return gpu_power_J(p, t0, t1) / gpu_power_s(p, t0, t1);
> +}
> +
> +#endif /* IGT_GPU_POWER_H */
> diff --git a/lib/meson.build b/lib/meson.build
> index 0eb5585d7..89de06e69 100644
> --- a/lib/meson.build
> +++ b/lib/meson.build
> @@ -9,9 +9,11 @@ lib_sources = [
>   	'igt_debugfs.c',
>   	'igt_device.c',
>   	'igt_aux.c',
> +	'igt_gpu_power.c',
>   	'igt_gt.c',
>   	'igt_gvt.c',
>   	'igt_matrix.c',
> +	'igt_perf.c',
>   	'igt_primes.c',
>   	'igt_rand.c',
>   	'igt_stats.c',
> 

Nitpicks or not:

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko