tests/gem_evict_everything: add swapping and forked subtests

Much better at hitting the list corruption here on my machines
than what we have thus far.

Note that somehow I just can't reproduce the bug any more. No idea
why. But I guess it's time to simply push this pile out.

v2: Limit threads and rounds to something reasonable.

v3: Use igt_permute_array to avoid EINVAL due to duplicated bo.

v4:
- Add a variant of the forked tests with multiple drm fds.
- Tune the swapped forked tests a bit to complete in a reasonable
  amount of time.

v5: Add some memory pressure from the cpu by using cpu mmaps (which
directly hit shmem, so bypass gem completely).

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

tests/gem_evict_everything.c

@@ -118,6 +118,134 @@ copy(int fd, uint32_t dst, uint32_t src, uint32_t *all_bo, int n_bo, int error)
 	free(obj);
 }
 
+static void exchange_uint32_t(void *array, unsigned i, unsigned j)
+{
+	uint32_t *i_arr = array;
+	uint32_t i_tmp;
+
+	i_tmp = i_arr[i];
+	i_arr[i] = i_arr[j];
+	i_arr[j] = i_tmp;
+}
+
+#define min(a, b) ((a) < (b) ? (a) : (b))
+
+#define INTERRUPTIBLE	(1 << 0)
+#define SWAPPING	(1 << 1)
+#define DUP_DRMFD	(1 << 2)
+#define MEMORY_PRESSURE	(1 << 3)
+#define ALL_FLAGS	(INTERRUPTIBLE | SWAPPING | DUP_DRMFD | MEMORY_PRESSURE)
+
+static void forked_evictions(int fd, int size, int count,
+			     unsigned flags)
+{
+	uint32_t *bo;
+	int n, pass, l;
+	int num_threads = sysconf(_SC_NPROCESSORS_ONLN);
+	int bo_count;
+
+	igt_require((uint64_t)count * size / (1024 * 1024) < intel_get_total_ram_mb() * 9 / 10);
+
+	if (flags & SWAPPING) {
+		igt_require(intel_get_total_ram_mb() / 4 < intel_get_total_swap_mb());
+		bo_count = intel_get_total_ram_mb() * 11 / 10;
+
+		if (bo_count < count)
+			bo_count = count;
+	} else
+		bo_count = count;
+
+	bo = malloc(bo_count*sizeof(*bo));
+	igt_assert(bo);
+
+	for (n = 0; n < bo_count; n++)
+		bo[n] = gem_create(fd, size);
+
+	igt_fork(i, min(count, num_threads * 4)) {
+		int realfd = fd;
+		int num_passes = flags & SWAPPING ? 10 : 100;
+
+		/* Every fork should have a different permutation! */
+		srand(i * 63);
+
+		if (flags & INTERRUPTIBLE)
+			igt_fork_signal_helper();
+
+		igt_permute_array(bo, bo_count, exchange_uint32_t);
+
+		if (flags & DUP_DRMFD) {
+			realfd = drm_open_any();
+
+			/* We can overwrite the bo array since we're forked. */
+			for (l = 0; l < count; l++) {
+				uint32_t flink;
+
+				flink = gem_flink(fd, bo[l]);
+				bo[l] = gem_open(realfd, flink);
+			}
+
+		}
+
+		for (pass = 0; pass < num_passes; pass++) {
+			copy(realfd, bo[0], bo[1], bo, count, 0);
+
+			for (l = 0; l < count && (flags & MEMORY_PRESSURE); l++) {
+				uint32_t *base = gem_mmap__cpu(realfd, bo[l],
+							       size,
+							       PROT_READ | PROT_WRITE);
+				memset(base, 0, size);
+				munmap(base, size);
+			}
+		}
+
+		if (flags & INTERRUPTIBLE)
+			igt_stop_signal_helper();
+
+		/* drmfd closing will take care of additional bo refs */
+		if (flags & DUP_DRMFD)
+			close(realfd);
+	}
+
+	igt_waitchildren();
+
+	for (n = 0; n < bo_count; n++)
+		gem_close(fd, bo[n]);
+	free(bo);
+}
+
+static void swapping_evictions(int fd, int size, int count)
+{
+	uint32_t *bo;
+	int i, n, pass;
+	int bo_count;
+
+	igt_require((uint64_t)count * size / (1024 * 1024) < intel_get_total_ram_mb() * 9 / 10);
+
+	igt_require(intel_get_total_ram_mb() / 4 < intel_get_total_swap_mb());
+	bo_count = intel_get_total_ram_mb() * 11 / 10;
+
+	if (bo_count < count)
+		bo_count = count;
+
+	bo = malloc(bo_count*sizeof(*bo));
+	igt_assert(bo);
+
+	for (n = 0; n < bo_count; n++)
+		bo[n] = gem_create(fd, size);
+
+	for (i = 0; i < bo_count/32; i++) {
+		igt_permute_array(bo, bo_count, exchange_uint32_t);
+
+		for (pass = 0; pass < 100; pass++) {
+			copy(fd, bo[0], bo[1], bo, count, 0);
+		}
+	}
+
+	for (n = 0; n < bo_count; n++)
+		gem_close(fd, bo[n]);
+	free(bo);
+}
+
 static void minor_evictions(int fd, int size, int count)
 {
 	uint32_t *bo, *sel;
@@ -169,38 +297,58 @@ static void major_evictions(int fd, int size, int count)
 	free(bo);
 }
 
-int fd;
-
 int main(int argc, char **argv)
 {
-	int size, count;
+	int size, count, fd;
+	size = count = 0;
+	fd = -1;
 
 	igt_subtest_init(argc, argv);
 
 	igt_skip_on_simulation();
 
-	igt_fixture
+	igt_fixture {
 		fd = drm_open_any();
 
-	igt_subtest("minor-normal") {
 		size = 1024 * 1024;
 		count = 3*gem_aperture_size(fd) / size / 4;
-		minor_evictions(fd, size, count);
 	}
 
+	for (unsigned flags = 0; flags < ALL_FLAGS + 1; flags++) {
+		igt_subtest_f("forked%s%s%s-%s",
+			      flags & SWAPPING ? "-swapping" : "",
+			      flags & DUP_DRMFD ? "-multifd" : "",
+			      flags & MEMORY_PRESSURE ? "-mempressure" : "",
+			      flags & INTERRUPTIBLE ? "interruptible" : "normal") {
+			forked_evictions(fd, size, count, flags);
+		}
+	}
+
+	igt_subtest("swapping-normal")
+		swapping_evictions(fd, size, count);
+
+	igt_subtest("minor-normal")
+		minor_evictions(fd, size, count);
+
 	igt_subtest("major-normal") {
 		size = 3*gem_aperture_size(fd) / 4;
 		count = 4;
 		major_evictions(fd, size, count);
 	}
 
-	igt_fork_signal_helper();
-	igt_subtest("minor-interruptible") {
+	igt_fixture {
 		size = 1024 * 1024;
 		count = 3*gem_aperture_size(fd) / size / 4;
-		minor_evictions(fd, size, count);
 	}
 
+	igt_fork_signal_helper();
+
+	igt_subtest("swapping-interruptible")
+		swapping_evictions(fd, size, count);
+
+	igt_subtest("minor-interruptible")
+		minor_evictions(fd, size, count);
+
 	igt_subtest("major-interruptible") {
 		size = 3*gem_aperture_size(fd) / 4;
 		count = 4;