Re: [PATCH i-g-t] benchmarks: Add VKMS benchmark

[Pekka Paalanen <pekka.paalanen@haloniitty.fi>]

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On Wed, 07 Feb 2024 17:17:15 -0300
Arthur Grillo <arthurgrillo@riseup.net> wrote:

> Create a benchmark for the VKMS driver. Use a KMS layout with deliberate
> odd sizes to try to avoid alignment accidents and run it for FRAME_COUNT
> frames flipping framebuffers in each plane.
> 
> Link: https://lore.kernel.org/all/20240202214527.1d97c881@ferris.localdomain/
> Suggested-by: Pekka Paalanen <pekka.paalanen@haloniitty.fi>
> Signed-off-by: Arthur Grillo <arthurgrillo@riseup.net>
> ---
> This benchmark was suggested by Pekka Paalanen on [1] to better analyse
> possible performance regression on the Virtual Kernel Modesetting(VKMS)
> driver.
> 
> With this benchmark I was able to determine two performance regression:
> 
> - 322d716a3e8a ("drm/vkms: isolate pixel conversion functionality")
> - cc4fd2934d41 ("drm/vkms: Isolate writeback pixel conversion functions")
> 
> [1]: https://lore.kernel.org/all/20240202214527.1d97c881@ferris.localdomain/
> ---
>  benchmarks/meson.build   |   1 +
>  benchmarks/vkms_stress.c | 203 +++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 204 insertions(+)
> 
> diff --git a/benchmarks/meson.build b/benchmarks/meson.build
> index c451268bc44f..3aa66d6dffe2 100644
> --- a/benchmarks/meson.build
> +++ b/benchmarks/meson.build
> @@ -20,6 +20,7 @@ benchmark_progs = [
>  	'kms_vblank',
>  	'prime_lookup',
>  	'vgem_mmap',
> +	'vkms_stress',
>  ]
>  
>  benchmarksdir = join_paths(libexecdir, 'benchmarks')
> diff --git a/benchmarks/vkms_stress.c b/benchmarks/vkms_stress.c
> new file mode 100644
> index 000000000000..b9128c208861
> --- /dev/null
> +++ b/benchmarks/vkms_stress.c
> @@ -0,0 +1,203 @@
> +/*
> + * Copyright © 2024 Arthur Grillo
> + *
> + * 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.
> + *
> + * Authors:
> + *    Arthur Grillo <arthurgrillo@riseup.net>
> + *
> + */
> +
> +#include "igt.h"
> +
> +#define FRAME_COUNT 100
> +
> +struct rect_t {
> +	int x, y;
> +	int width, height;
> +};
> +
> +struct plane_t {
> +	igt_plane_t *base;
> +	struct rect_t rect;
> +	uint32_t format;
> +	struct igt_fb fbs[2];
> +};
> +
> +struct kms_t {
> +	struct plane_t primary;
> +	struct plane_t overlay_a;
> +	struct plane_t overlay_b;
> +	struct plane_t writeback;
> +};
> +
> +struct data_t {
> +	int fd;
> +	igt_display_t display;
> +	igt_output_t *wb_output;
> +	drmModeModeInfo *mode;
> +	struct kms_t kms;
> +};
> +
> +static void plane_create_fb(struct plane_t *plane, int fd, size_t index)
> +{
> +	igt_create_fb(fd, plane->rect.width, plane->rect.height,
> +			plane->format, DRM_FORMAT_MOD_LINEAR,
> +			&plane->fbs[index]);
> +}
> +
> +static void plane_create_color_fb(struct plane_t *plane, int fd, size_t index, double r, double g,
> +				   double b)
> +{
> +	igt_create_color_fb(fd, plane->rect.width, plane->rect.height,
> +			plane->format, DRM_FORMAT_MOD_LINEAR,
> +			r, g, b,
> +			&plane->fbs[index]);
> +}
> +
> +static void plane_setup(struct plane_t *plane, int index)
> +{
> +	igt_plane_set_size(plane->base, plane->rect.width, plane->rect.height);
> +	igt_plane_set_position(plane->base, plane->rect.x, plane->rect.y);
> +	igt_plane_set_fb(plane->base, &plane->fbs[index]);
> +}
> +
> +static void gen_fbs(struct data_t *data)
> +{
> +	struct kms_t *kms = &data->kms;
> +	drmModeModeInfo *mode = igt_output_get_mode(data->wb_output);
> +
> +	for (int i = 0; i < 2; i++) {
> +		plane_create_color_fb(&kms->primary, data->fd, i, !i, i, i);
> +
> +		plane_create_color_fb(&kms->overlay_a, data->fd, i, i, !i, i);
> +
> +		plane_create_color_fb(&kms->overlay_b, data->fd, i, i, i, !i);
> +
> +		kms->writeback.rect.width = mode->hdisplay;
> +		kms->writeback.rect.height = mode->vdisplay;
> +		plane_create_fb(&kms->writeback, data->fd, i);
> +	}
> +}
> +
> +static igt_output_t *find_wb_output(struct data_t *data)
> +{
> +	for (int i = 0; i < data->display.n_outputs; i++) {
> +		igt_output_t *output = &data->display.outputs[i];
> +
> +		if (output->config.connector->connector_type != DRM_MODE_CONNECTOR_WRITEBACK)
> +			continue;
> +
> +		return output;
> +
> +	}
> +
> +	return NULL;
> +}
> +
> +static struct kms_t default_kms = {
> +	.primary = {
> +		.rect = {
> +			.x = 101, .y = 0,
> +			.width = 3639, .height = 2161,
> +		},
> +		.format = DRM_FORMAT_XRGB8888,
> +	},
> +	.overlay_a = {
> +		.rect = {
> +			.x = 201, .y = 199,
> +			.width = 3033, .height = 1777,
> +		},
> +		.format = DRM_FORMAT_XRGB16161616,
> +	},
> +	.overlay_b = {
> +		.rect = {
> +			.x = 1800, .y = 250,
> +			.width = 1507, .height = 1400,
> +		},
> +		.format = DRM_FORMAT_ARGB8888,
> +	},
> +	.writeback = {
> +		.rect = {
> +			.x = 0, .y = 0,
> +			// Size is to be determined at runtime
> +		},
> +		.format = DRM_FORMAT_XRGB8888,
> +	},
> +};
> +
> +
> +igt_simple_main
> +{
> +	struct data_t data;
> +	enum pipe pipe = PIPE_NONE;
> +
> +	data.kms = default_kms;
> +

Hi Arthur,

all the above looks really good!

Some things below look strange to me, but I don't know the igt API.

> +	data.fd = drm_open_driver_master(DRIVER_ANY);
> +
> +	igt_display_require(&data.display, data.fd);
> +
> +	kmstest_set_vt_graphics_mode();
> +
> +	igt_display_require(&data.display, data.fd);

Are you supposed to call igt_display_require twice?

> +	igt_require(data.display.is_atomic);
> +
> +	igt_display_require_output(&data.display);
> +
> +	igt_require(data.wb_output);
> +	igt_display_reset(&data.display);
> +
> +	data.wb_output = find_wb_output(&data);

Should igt_require(data.wb_output) be after find_wb_output?

> +
> +	for_each_pipe(&data.display, pipe) {
> +		igt_debug("Selecting pipe %s to %s\n",
> +			  kmstest_pipe_name(pipe),
> +			  igt_output_name(data.wb_output));
> +		igt_output_set_pipe(data.wb_output, pipe);

Isn't this strange if there are multiple pipes?

> +	}
> +
> +	igt_display_commit_atomic(&data.display, DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);

What's this commit needed for?

> +
> +	gen_fbs(&data);
> +
> +	data.kms.primary.base = igt_output_get_plane_type(data.wb_output, DRM_PLANE_TYPE_PRIMARY);
> +	data.kms.overlay_a.base = igt_output_get_plane_type_index(data.wb_output,
> +								  DRM_PLANE_TYPE_OVERLAY, 0);
> +	data.kms.overlay_b.base = igt_output_get_plane_type_index(data.wb_output,
> +								  DRM_PLANE_TYPE_OVERLAY, 1);
> +
> +	for (int i = 0; i < FRAME_COUNT; i++) {
> +		int fb_index = i % 2;
> +
> +		plane_setup(&data.kms.primary, fb_index);
> +
> +		plane_setup(&data.kms.overlay_a, fb_index);
> +
> +		plane_setup(&data.kms.overlay_b, fb_index);
> +
> +		igt_output_set_writeback_fb(data.wb_output, &data.kms.writeback.fbs[fb_index]);
> +
> +		igt_display_commit2(&data.display, COMMIT_ATOMIC);
> +	}
> +
> +	igt_display_fini(&data.display);
> +	drm_close_driver(data.fd);
> +}

Aside those questions, I'm already happy giving a

Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>


Thanks,
pq

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