tests/gem_shrink: Background, direct and OOM shrinker plus userptr tests

index c8e05814ee70..d838a750fe68 100644
@@ -26,6 +26,9 @@
  *
  * Exercise the shrinker by overallocating GEM objects
  */
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
 
 #include "igt.h"
 #include "igt_gt.h"

@@ -366,6 +369,210 @@ static void reclaim(unsigned engine, int timeout)
 	close(fd);
 }
 
+static unsigned long get_meminfo(const char *info, const char *tag)
+{
+	const char *str;
+	unsigned long val;
+
+	str = strstr(info, tag);
+	if (str && sscanf(str + strlen(tag), " %lu", &val) == 1)
+		return val >> 10;
+
+	igt_warn("Unrecognised /proc/meminfo field: '%s'\n", tag);
+	return 0;
+}
+
+static unsigned long get_avail_ram_mb(void)
+{
+	int fd;
+	int ret;
+	char buf[4096];
+	unsigned long ram;
+
+	fd = open("/proc/meminfo", O_RDONLY);
+	igt_assert_fd(fd);
+
+	ret = read(fd, buf, sizeof(buf));
+	igt_assert(ret >= 0);
+
+	close(fd);
+
+	ram = get_meminfo(buf, "MemAvailable:");
+	ram += get_meminfo(buf, "Buffers:");
+	ram += get_meminfo(buf, "Cached:");
+	ram += get_meminfo(buf, "SwapCached:");
+
+	return ram;
+}
+
+struct test {
+#define TEST_BO		(1)
+#define TEST_USERPTR	(2)
+	unsigned int flags;
+	int fd;
+};
+
+static uint32_t __get_pages(int fd, unsigned long alloc)
+{
+	uint32_t handle = gem_create(fd, alloc);
+
+	gem_set_domain(fd, handle, I915_GEM_DOMAIN_GTT, 0);
+	gem_madvise(fd, handle, I915_MADV_DONTNEED);
+
+	return handle;
+}
+
+struct test_obj {
+	void *ptr;
+	uint32_t handle;
+};
+
+static void
+__get_userptr(int fd, struct test_obj *obj, unsigned long sz)
+{
+	struct local_i915_gem_userptr userptr = { };
+	void *ptr;
+
+	igt_assert_eq(sz & 4095, 0);
+
+	ptr = mmap(NULL, sz, PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	assert(ptr != MAP_FAILED);
+
+	userptr.user_size = sz;
+	userptr.user_ptr = to_user_pointer(ptr);
+	do_ioctl(fd, LOCAL_IOCTL_I915_GEM_USERPTR, &userptr);
+
+	gem_set_domain(fd, userptr.handle, I915_GEM_DOMAIN_GTT, 0);
+
+	obj->ptr = ptr;
+	obj->handle = userptr.handle;
+}
+
+#define PAGE_SIZE 4096
+static void *mempressure(void *arg)
+{
+	struct test_obj *list = NULL;
+	struct test *test = arg;
+	const unsigned int sz_mb = 2;
+	const unsigned int sz = sz_mb << 20;
+	unsigned int n = 0, max = 0;
+	unsigned int blocks;
+
+	while (true) {
+		unsigned long ram_mb = get_avail_ram_mb();
+
+		if (!list) {
+			blocks = ram_mb / sz_mb;
+			list = calloc(blocks, sizeof(*list));
+			igt_assert(list);
+		} else if (ram_mb < 256) {
+			blocks = max + 1;
+		}
+
+		if (list[n].ptr || list[n].handle) {
+			if (test->flags & TEST_BO)
+				gem_close(test->fd, list[n].handle);
+			else
+				munmap(list[n].ptr, sz);
+		}
+
+		if (test->flags & TEST_BO) {
+			list[n].handle = __get_pages(test->fd, sz);
+		} else if (test->flags & TEST_USERPTR) {
+			__get_userptr(test->fd, &list[n], sz);
+		} else {
+			list[n].ptr = mmap(NULL, sz, PROT_WRITE,
+					   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+			assert(list[n].ptr != MAP_FAILED);
+
+			madvise(list[n].ptr, sz, MADV_HUGEPAGE);
+
+			for (size_t page = 0; page < sz; page += PAGE_SIZE)
+				*(volatile uint32_t *)((unsigned char *)list[n].ptr + page) = 0;
+		}
+
+		if (n > max)
+			max = n;
+
+		n++;
+
+		if (n >= blocks)
+			n = 0;
+	}
+
+	return NULL;
+}
+
+static void oom_adjust(const char *score)
+{
+        int fd;
+
+        fd = open("/proc/self/oom_score_adj", O_WRONLY);
+        igt_assert_fd(fd);
+        igt_assert(write(fd, score, sizeof(score)) == sizeof(score));
+        close(fd);
+}
+
+static void trigger_oom(void)
+{
+	const char *cmd = "f";
+        int fd;
+
+        fd = open("/proc/sysrq-trigger", O_WRONLY);
+        igt_assert_fd(fd);
+        igt_assert(write(fd, cmd, sizeof(cmd)) == sizeof(cmd));
+        close(fd);
+}
+
+static void reclaim_oom(unsigned int flags)
+{
+	unsigned int count = 0;
+
+	igt_assert_eq(__builtin_popcount(flags), 1);
+
+	oom_adjust("-1000");
+
+	do {
+		struct igt_helper_process gem_child = { };
+		struct igt_helper_process mem_child = { };
+
+		igt_debug("Iteration %u...\n", ++count);
+
+		igt_fork_helper(&mem_child) {
+			struct test mem = { };
+
+			oom_adjust("500");
+			mempressure(&mem);
+		}
+
+		igt_fork_helper(&gem_child) {
+			struct test gem = { .flags = flags };
+
+			oom_adjust("500");
+
+			gem.fd = drm_open_driver(DRIVER_INTEL);
+			igt_require_gem(gem.fd);
+
+			mempressure(&gem);
+
+			close(gem.fd);
+		}
+
+		for (unsigned long ram_mb = 0;
+		     (ram_mb = get_avail_ram_mb()) > 512;) {
+			igt_debug("[%u] %lu free mb\n", count, ram_mb);
+			sleep(1);
+		}
+
+		trigger_oom();
+
+		sleep(1);
+
+		igt_stop_helper(&mem_child);
+		igt_stop_helper(&gem_child);
+	} while (count < 300);
+}
+
 igt_main
 {
 	const struct test {

@@ -432,6 +639,12 @@ igt_main
 	igt_subtest("reclaim")
 		reclaim(I915_EXEC_DEFAULT, 2);
 
+	igt_subtest("two-reclaims-and-oom")
+		reclaim_oom(TEST_BO);
+
+	igt_subtest("two-reclaims-and-oom-userptr")
+		reclaim_oom(TEST_USERPTR);
+
 	for(const struct test *t = tests; t->name; t++) {
 		for(const struct mode *m = modes; m->suffix; m++) {
 			igt_subtest_f("%s%s", t->name, m->suffix)

index c8e05814ee70..acc12efed15e 100644
@@ -26,6 +26,9 @@
  *
  * Exercise the shrinker by overallocating GEM objects
  */
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
 
 #include "igt.h"
 #include "igt_gt.h"

@@ -366,6 +369,210 @@ static void reclaim(unsigned engine, int timeout)
 	close(fd);
 }
 
+static unsigned long get_meminfo(const char *info, const char *tag)
+{
+	const char *str;
+	unsigned long val;
+
+	str = strstr(info, tag);
+	if (str && sscanf(str + strlen(tag), " %lu", &val) == 1)
+		return val >> 10;
+
+	igt_warn("Unrecognised /proc/meminfo field: '%s'\n", tag);
+	return 0;
+}
+
+static unsigned long get_avail_ram_mb(void)
+{
+	int fd;
+	int ret;
+	char buf[4096];
+	unsigned long ram;
+
+	fd = open("/proc/meminfo", O_RDONLY);
+	igt_assert_fd(fd);
+
+	ret = read(fd, buf, sizeof(buf));
+	igt_assert(ret >= 0);
+
+	close(fd);
+
+	ram = get_meminfo(buf, "MemAvailable:");
+	ram += get_meminfo(buf, "Buffers:");
+	ram += get_meminfo(buf, "Cached:");
+	ram += get_meminfo(buf, "SwapCached:");
+
+	return ram;
+}
+
+struct test {
+#define TEST_BO		(1)
+#define TEST_USERPTR	(2)
+	unsigned int flags;
+	int fd;
+};
+
+static uint32_t __get_pages(int fd, unsigned long alloc)
+{
+	uint32_t handle = gem_create(fd, alloc);
+
+	gem_set_domain(fd, handle, I915_GEM_DOMAIN_GTT, 0);
+	gem_madvise(fd, handle, I915_MADV_DONTNEED);
+
+	return handle;
+}
+
+struct test_obj {
+	void *ptr;
+	uint32_t handle;
+};
+
+static void
+__get_userptr(int fd, struct test_obj *obj, unsigned long sz)
+{
+	struct local_i915_gem_userptr userptr = { };
+	void *ptr;
+
+	igt_assert_eq(sz & 4095, 0);
+
+	ptr = mmap(NULL, sz, PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	assert(ptr != MAP_FAILED);
+
+	userptr.user_size = sz;
+	userptr.user_ptr = to_user_pointer(ptr);
+	do_ioctl(fd, LOCAL_IOCTL_I915_GEM_USERPTR, &userptr);
+
+	gem_set_domain(fd, userptr.handle, I915_GEM_DOMAIN_GTT, 0);
+
+	obj->ptr = ptr;
+	obj->handle = userptr.handle;
+}
+
+#define PAGE_SIZE 4096
+static void *mempressure(void *arg)
+{
+	struct test_obj *list = NULL;
+	struct test *test = arg;
+	const unsigned int sz_mb = 2;
+	const unsigned int sz = sz_mb << 20;
+	unsigned int n = 0, max = 0;
+	unsigned int blocks;
+
+	while (true) {
+		unsigned long ram_mb = get_avail_ram_mb();
+
+		if (!list) {
+			blocks = ram_mb / sz_mb;
+			list = calloc(blocks, sizeof(*list));
+			igt_assert(list);
+		} else if (ram_mb < 256) {
+			blocks = max + 1;
+		}
+
+		if (list[n].ptr || list[n].handle) {
+			if (test->flags & TEST_BO)
+				gem_close(test->fd, list[n].handle);
+			else
+				munmap(list[n].ptr, sz);
+		}
+
+		if (test->flags & TEST_BO) {
+			list[n].handle = __get_pages(test->fd, sz);
+		} else if (test->flags & TEST_USERPTR) {
+			__get_userptr(test->fd, &list[n], sz);
+		} else {
+			list[n].ptr = mmap(NULL, sz, PROT_WRITE,
+					   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+			assert(list[n].ptr != MAP_FAILED);
+
+			madvise(list[n].ptr, sz, MADV_HUGEPAGE);
+
+			for (size_t page = 0; page < sz; page += PAGE_SIZE)
+				*(volatile uint32_t *)((unsigned char *)list[n].ptr + page) = 0;
+		}
+
+		if (n > max)
+			max = n;
+
+		n++;
+
+		if (n >= blocks)
+			n = 0;
+	}
+
+	return NULL;
+}
+
+static void oom_adjust(const char *score)
+{
+        int fd;
+
+        fd = open("/proc/self/oom_score_adj", O_WRONLY);
+        igt_assert_fd(fd);
+        igt_assert(write(fd, score, sizeof(score)) == sizeof(score));
+        close(fd);
+}
+
+static void trigger_oom(void)
+{
+	const char *cmd = "f";
+        int fd;
+
+        fd = open("/proc/sysrq-trigger", O_WRONLY);
+        igt_assert_fd(fd);
+        igt_assert(write(fd, cmd, sizeof(cmd)) == sizeof(cmd));
+        close(fd);
+}
+
+static void reclaim_oom(unsigned int flags)
+{
+	unsigned int count = 0;
+
+	igt_assert_eq(__builtin_popcount(flags), 1);
+
+	oom_adjust("-1000");
+
+	do {
+		struct igt_helper_process gem_child = { };
+		struct igt_helper_process mem_child = { };
+
+		igt_debug("Iteration %u...\n", ++count);
+
+		igt_fork_helper(&mem_child) {
+			struct test mem = { };
+
+			oom_adjust("500");
+			mempressure(&mem);
+		}
+
+		igt_fork_helper(&gem_child) {
+			struct test gem = { .flags = flags };
+
+			oom_adjust("500");
+
+			gem.fd = drm_open_driver(DRIVER_INTEL);
+			igt_require_gem(gem.fd);
+
+			mempressure(&gem);
+
+			close(gem.fd);
+		}
+
+		for (unsigned long ram_mb = 0;
+		     (ram_mb = get_avail_ram_mb()) > 512;) {
+			igt_debug("[%u] %lu free mb\n", count, ram_mb);
+			sleep(1);
+		}
+
+		trigger_oom();
+
+		sleep(1);
+
+		igt_stop_helper(&mem_child);
+		igt_stop_helper(&gem_child);
+	} while (count < 5);
+}
+
 igt_main
 {
 	const struct test {

@@ -432,6 +639,12 @@ igt_main
 	igt_subtest("reclaim")
 		reclaim(I915_EXEC_DEFAULT, 2);
 
+	igt_subtest("two-reclaims-and-oom")
+		reclaim_oom(TEST_BO);
+
+	igt_subtest("two-reclaims-and-oom-userptr")
+		reclaim_oom(TEST_USERPTR);
+
 	for(const struct test *t = tests; t->name; t++) {
 		for(const struct mode *m = modes; m->suffix; m++) {
 			igt_subtest_f("%s%s", t->name, m->suffix)