diff options
author | Chris Wilson <chris@chris-wilson.co.uk> | 2015-07-23 15:18:22 +0100 |
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committer | Chris Wilson <chris@chris-wilson.co.uk> | 2015-07-23 15:52:53 +0100 |
commit | d88981f62bdcaafeb393bac22db6719d43de88c7 (patch) | |
tree | 9e47cdf42f84368166dd05118b4b19e26d86f96a /benchmarks/kms_vblank.c | |
parent | af510c249d6d374267a2052da202ea7c3a6b20cf (diff) |
benchmarks: Measure round-trip time for an immediate vblanks
By measuring both the query and the event round trip time, we can make a
reasonable estimate of how long it takes for the query to send the
vblank following an interrupt.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Diffstat (limited to 'benchmarks/kms_vblank.c')
-rw-r--r-- | benchmarks/kms_vblank.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/benchmarks/kms_vblank.c b/benchmarks/kms_vblank.c new file mode 100644 index 00000000..f9dbe3d0 --- /dev/null +++ b/benchmarks/kms_vblank.c @@ -0,0 +1,180 @@ +/* + * Copyright © 2015 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. + */ + +/** @file kms_vblank.c + * + * This is a test of performance of drmWaitVblank. + */ + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <unistd.h> +#include <fcntl.h> +#include <inttypes.h> +#include <errno.h> +#include <time.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <sys/wait.h> + +#include <drm.h> +#include <xf86drm.h> +#include "drmtest.h" + +static double elapsed(const struct timespec *start, + const struct timespec *end, + int loop) +{ + return (1e6*(end->tv_sec - start->tv_sec) + (end->tv_nsec - start->tv_nsec)/1000)/loop; +} + +static int crtc0_active(int fd) +{ + union drm_wait_vblank vbl; + + memset(&vbl, 0, sizeof(vbl)); + vbl.request.type = DRM_VBLANK_RELATIVE; + return drmIoctl(fd, DRM_IOCTL_WAIT_VBLANK, &vbl) == 0; +} + +static void vblank_query(int fd, int busy) +{ + union drm_wait_vblank vbl; + struct timespec start, end; + unsigned long seq, count = 0; + struct drm_event_vblank event; + + memset(&vbl, 0, sizeof(vbl)); + + if (busy) { + vbl.request.type = DRM_VBLANK_RELATIVE | DRM_VBLANK_EVENT; + vbl.request.sequence = 120 + 12; + drmIoctl(fd, DRM_IOCTL_WAIT_VBLANK, &vbl); + } + + vbl.request.type = DRM_VBLANK_RELATIVE; + vbl.request.sequence = 0; + drmIoctl(fd, DRM_IOCTL_WAIT_VBLANK, &vbl); + seq = vbl.reply.sequence; + + clock_gettime(CLOCK_MONOTONIC, &start); + do { + vbl.request.type = DRM_VBLANK_RELATIVE; + vbl.request.sequence = 0; + drmIoctl(fd, DRM_IOCTL_WAIT_VBLANK, &vbl); + count++; + } while ((vbl.reply.sequence - seq) <= 120); + clock_gettime(CLOCK_MONOTONIC, &end); + + printf("%f\n", 1e6/elapsed(&start, &end, count)); + if (busy) + read(fd, &event, sizeof(event)); +} + +static void vblank_event(int fd, int busy) +{ + union drm_wait_vblank vbl; + struct timespec start, end; + unsigned long seq, count = 0; + struct drm_event_vblank event; + + memset(&vbl, 0, sizeof(vbl)); + + if (busy) { + vbl.request.type = DRM_VBLANK_RELATIVE | DRM_VBLANK_EVENT; + vbl.request.sequence = 120 + 12; + drmIoctl(fd, DRM_IOCTL_WAIT_VBLANK, &vbl); + } + + vbl.request.type = DRM_VBLANK_RELATIVE; + vbl.request.sequence = 0; + drmIoctl(fd, DRM_IOCTL_WAIT_VBLANK, &vbl); + seq = vbl.reply.sequence; + + clock_gettime(CLOCK_MONOTONIC, &start); + do { + vbl.request.type = DRM_VBLANK_RELATIVE | DRM_VBLANK_EVENT; + vbl.request.sequence = 0; + drmIoctl(fd, DRM_IOCTL_WAIT_VBLANK, &vbl); + + read(fd, &event, sizeof(event)); + count++; + } while ((event.sequence - seq) <= 120); + clock_gettime(CLOCK_MONOTONIC, &end); + + printf("%f\n", 1e6/elapsed(&start, &end, count)); + if (busy) + read(fd, &event, sizeof(event)); +} + +int main(int argc, char **argv) +{ + int fd, c; + int busy = 0, loops = 5; + enum what { EVENTS, QUERIES } what = EVENTS; + + while ((c = getopt (argc, argv, "b:w:r:")) != -1) { + switch (c) { + case 'b': + if (strcmp(optarg, "busy") == 0) + busy = 1; + else if (strcmp(optarg, "idle") == 0) + busy = 0; + else + abort(); + break; + + case 'w': + if (strcmp(optarg, "event") == 0) + what = EVENTS; + else if (strcmp(optarg, "query") == 0) + what = QUERIES; + else + abort(); + break; + case 'r': + loops = atoi(optarg); + if (loops < 1) + loops = 1; + } + } + + fd = drm_open_any(); + if (!crtc0_active(fd)) { + fprintf(stderr, "CRTC/pipe 0 not active\n"); + return 77; + } + + while (loops--) { + switch (what) { + case EVENTS: + vblank_event(fd, busy); + break; + case QUERIES: + vblank_query(fd, busy); + break; + } + } + return 0; +} |