igt/gem_close_race: Increase GPU load

Increate the GPU load slightly, but mitigate the CPU overhead from
clflushing by keeping the object alive using flink. This has also the
side-effect of magnifying the desired busy-close race.

References: https://bugs.freedesktop.org/show_bug.cgi?id=71029
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/tests/gem_close_race.c b/tests/gem_close_race.c
index 02a408a..c9128f2 100644 (file)
--- a/tests/gem_close_race.c
+++ b/tests/gem_close_race.c
@@ -42,7 +42,7 @@
 #include "drmtest.h"
 #include "intel_chipset.h"
 
-#define OBJECT_SIZE 4096
+#define OBJECT_SIZE (256 * 1024)
 
 #define COPY_BLT_CMD           (2<<29|0x53<<22|0x6)
 #define BLT_WRITE_ALPHA                (1<<21)
@@ -151,6 +151,7 @@ static void run(int child)
 
 struct thread {
        pthread_mutex_t mutex;
+       int device;
        int fds[NUM_FD];
        int done;
 };
@@ -158,58 +159,58 @@ struct thread {
 static void *thread_run(void *_data)
 {
        struct thread *t = _data;
+       uint32_t handle = gem_create(t->device, OBJECT_SIZE);
+       struct drm_gem_open arg = { gem_flink(t->device, handle) };
 
        pthread_mutex_lock(&t->mutex);
        while (!t->done) {
                pthread_mutex_unlock(&t->mutex);
 
                for (int n = 0; n < NUM_FD; n++) {
-                       struct drm_i915_gem_create create;
+                       int fd = t->fds[n];
 
-                       create.handle = 0;
-                       create.size = OBJECT_SIZE;
-                       drmIoctl(t->fds[n], DRM_IOCTL_I915_GEM_CREATE, &create);
-                       if (create.handle == 0)
+                       arg.handle = 0;
+                       drmIoctl(fd, DRM_IOCTL_GEM_OPEN, &arg);
+                       if (arg.handle == 0)
                                continue;
 
-                       selfcopy(t->fds[n], create.handle, 100);
+                       selfcopy(fd, arg.handle, 100);
 
-                       drmIoctl(t->fds[n], DRM_IOCTL_GEM_CLOSE, &create.handle);
+                       drmIoctl(fd, DRM_IOCTL_GEM_CLOSE, &arg.handle);
                }
 
                pthread_mutex_lock(&t->mutex);
        }
        pthread_mutex_unlock(&t->mutex);
 
+       gem_close(t->device, handle);
        return 0;
 }
 
 static void *thread_busy(void *_data)
 {
        struct thread *t = _data;
-       int n;
+       uint32_t handle = gem_create(t->device, OBJECT_SIZE);
+       struct drm_gem_open arg = { gem_flink(t->device, handle) };
 
        pthread_mutex_lock(&t->mutex);
        while (!t->done) {
-               struct drm_i915_gem_create create;
                struct drm_i915_gem_busy busy;
+               int fd = t->fds[rand() % NUM_FD];
 
                pthread_mutex_unlock(&t->mutex);
 
-               n  = rand() % NUM_FD;
-
-               create.handle = 0;
-               create.size = OBJECT_SIZE;
-               drmIoctl(t->fds[n], DRM_IOCTL_I915_GEM_CREATE, &create);
-               if (create.handle == 0)
+               arg.handle = 0;
+               drmIoctl(fd, DRM_IOCTL_GEM_OPEN, &arg);
+               if (arg.handle == 0)
                        continue;
 
-               selfcopy(t->fds[n], create.handle, 10);
+               selfcopy(fd, arg.handle, 10);
 
-               busy.handle = create.handle;
-               drmIoctl(t->fds[n], DRM_IOCTL_I915_GEM_BUSY, &busy);
+               busy.handle = arg.handle;
+               drmIoctl(fd, DRM_IOCTL_I915_GEM_BUSY, &busy);
 
-               drmIoctl(t->fds[n], DRM_IOCTL_GEM_CLOSE, &create.handle);
+               drmIoctl(fd, DRM_IOCTL_GEM_CLOSE, &arg.handle);
 
                usleep(10*1000);
 
@@ -217,6 +218,7 @@ static void *thread_busy(void *_data)
        }
        pthread_mutex_unlock(&t->mutex);
 
+       gem_close(t->device, handle);
        return 0;
 }
 
@@ -250,6 +252,7 @@ igt_main
                igt_assert(data);
 
                pthread_mutex_init(&data->mutex, NULL);
+               data->device = open(device, O_RDWR);
                for (n = 0; n < NUM_FD; n++)
                        data->fds[n] = open(device, O_RDWR);
 
@@ -275,6 +278,7 @@ igt_main
 
                for (n = 0; n < NUM_FD; n++)
                        close(data->fds[n]);
+               close(data->device);
                free(data);
        }
 }