tests/gem_shrink.c - platform/external/igt-gpu-tools - Gitiles

 /*
  * Copyright © 2016 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 gem_shrink.c
  *
  * Exercise the shrinker by overallocating GEM objects
  */

 #include "igt.h"
 #include "igt_gt.h"
 #include "igt_debugfs.h"
 #include "igt_sysfs.h"

 #ifndef MADV_FREE
 #define MADV_FREE 8
 #endif

 static unsigned int engines[16], nengine;

 static void get_pages(int fd, uint64_t 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);
 }

 static void pwrite_(int fd, uint64_t alloc)
 {
 	uint32_t tmp;
 	uint32_t handle = gem_create(fd, alloc);
 	for (int page = 0; page < alloc>>12; page++)
 		gem_write(fd, handle, (page + page % 4095) & ~3, &tmp, 4);
 	gem_madvise(fd, handle, I915_MADV_DONTNEED);
 }

 static void pread_(int fd, uint64_t alloc)
 {
 	uint32_t tmp;
 	uint32_t handle = gem_create(fd, alloc);
 	for (int page = 0; page < alloc>>12; page++)
 		gem_read(fd, handle, (page + page % 4095) & ~3, &tmp, 4);
 	gem_madvise(fd, handle, I915_MADV_DONTNEED);
 }

 static void mmap_gtt(int fd, uint64_t alloc)
 {
 	uint32_t handle = gem_create(fd, alloc);
 	uint32_t *ptr = gem_mmap__gtt(fd, handle, alloc, PROT_WRITE);
 	for (int page = 0; page < alloc>>12; page++)
 		ptr[page<<10] = 0;
 	munmap(ptr, alloc);
 	gem_madvise(fd, handle, I915_MADV_DONTNEED);
 }

 static void mmap_cpu(int fd, uint64_t alloc)
 {
 	uint32_t handle = gem_create(fd, alloc);
 	uint32_t *ptr = gem_mmap__cpu(fd, handle, 0, alloc, PROT_WRITE);
 	for (int page = 0; page < alloc>>12; page++)
 		ptr[page<<10] = 0;
 	munmap(ptr, alloc);
 	gem_madvise(fd, handle, I915_MADV_DONTNEED);
 }

 static void execbuf1(int fd, uint64_t alloc)
 {
 	const uint32_t bbe = MI_BATCH_BUFFER_END;
 	struct drm_i915_gem_exec_object2 obj;
 	struct drm_i915_gem_execbuffer2 execbuf;

 	memset(&obj, 0, sizeof(obj));
 	memset(&execbuf, 0, sizeof(execbuf));
 	execbuf.buffers_ptr = to_user_pointer(&obj);
 	execbuf.buffer_count = 1;

 	obj.handle = gem_create(fd, alloc);
 	gem_write(fd, obj.handle, 0, &bbe, sizeof(bbe));
 	gem_execbuf(fd, &execbuf);
 	gem_madvise(fd, obj.handle, I915_MADV_DONTNEED);
 }

 /* Since we want to trigger oom (SIGKILL), we don't want small allocations
  * to fail and generate a false error (SIGSEGV)! So we redirect allocations
  * though GEM objects, which should be much more likely to trigger oom. There
  * are still small allocations within the kernel, so still a small chance of
  * ENOMEM instead of a full oom.
  */
 static void *__gem_calloc(int fd, size_t count, size_t size, uint64_t *out_size)
 {
 	uint32_t handle;
 	uint64_t total;
 	void *ptr;

 	total = count * size;
 	total = (total + 4095) & -4096;

 	handle = gem_create(fd, total);
 	ptr = gem_mmap__cpu(fd, handle, 0, total, PROT_WRITE);
 	gem_set_domain(fd, handle, I915_GEM_DOMAIN_CPU, I915_GEM_DOMAIN_CPU);
 	gem_close(fd, handle);

 	*out_size = total;
 	return ptr;
 }

 static void execbufN(int fd, uint64_t alloc)
 {
 	const uint32_t bbe = MI_BATCH_BUFFER_END;
 	struct drm_i915_gem_exec_object2 *obj;
 	struct drm_i915_gem_execbuffer2 execbuf;
 	int count = alloc >> 20;
 	uint64_t obj_size;

 	obj = __gem_calloc(fd, alloc + 1, sizeof(*obj), &obj_size);
 	memset(&execbuf, 0, sizeof(execbuf));

 	obj[count].handle = gem_create(fd, 4096);
 	gem_write(fd, obj[count].handle, 0, &bbe, sizeof(bbe));

 	for (int i = 1; i <= count; i++) {
 		int j = count - i;

 		obj[j].handle = gem_create(fd, 1 << 20);
 		execbuf.buffers_ptr = to_user_pointer(&obj[j]);
 		execbuf.buffer_count = i + 1;
 		gem_execbuf(fd, &execbuf);
 	}

 	for (int i = 0; i <= count; i++)
 		gem_madvise(fd, obj[i].handle, I915_MADV_DONTNEED);
 	munmap(obj, obj_size);
 }

 static void execbufX(int fd, uint64_t alloc)
 {
 	const uint32_t bbe = MI_BATCH_BUFFER_END;
 	struct drm_i915_gem_exec_object2 *obj;
 	struct drm_i915_gem_execbuffer2 execbuf;
 	int count = alloc >> 20;
 	uint64_t obj_size;

 	obj = __gem_calloc(fd, alloc + 1, sizeof(*obj), &obj_size);
 	memset(&execbuf, 0, sizeof(execbuf));

 	obj[count].handle = gem_create(fd, 4096);
 	gem_write(fd, obj[count].handle, 0, &bbe, sizeof(bbe));

 	for (int i = 1; i <= count; i++) {
 		int j = count - i;

 		obj[j+1].flags = 0;

 		obj[j].handle = gem_create(fd, 1 << 20);
 		obj[j].flags = EXEC_OBJECT_WRITE;

 		execbuf.buffers_ptr = to_user_pointer(&obj[j]);
 		execbuf.buffer_count = i + 1;
 		execbuf.flags = engines[j % nengine];
 		gem_execbuf(fd, &execbuf);
 	}

 	for (int i = 0; i <= count; i++)
 		gem_madvise(fd, obj[i].handle, I915_MADV_DONTNEED);
 	munmap(obj, obj_size);
 }

 static void hang(int fd, uint64_t alloc)
 {
 	const uint32_t bbe = MI_BATCH_BUFFER_END;
 	struct drm_i915_gem_exec_object2 *obj;
 	struct drm_i915_gem_execbuffer2 execbuf;
 	int count = alloc >> 20;
 	uint64_t obj_size;

 	obj = __gem_calloc(fd, alloc + 1, sizeof(*obj), &obj_size);
 	memset(&execbuf, 0, sizeof(execbuf));

 	obj[count].handle = gem_create(fd, 4096);
 	gem_write(fd, obj[count].handle, 0, &bbe, sizeof(bbe));

 	for (int i = 1; i <= count; i++) {
 		int j = count - i;

 		obj[j].handle = gem_create(fd, 1 << 20);
 		execbuf.buffers_ptr = to_user_pointer(&obj[j]);
 		execbuf.buffer_count = i + 1;
 		gem_execbuf(fd, &execbuf);
 	}

 	gem_close(fd, igt_hang_ring(fd, 0).spin->handle);
 	for (int i = 0; i <= count; i++)
 		gem_madvise(fd, obj[i].handle, I915_MADV_DONTNEED);
 	munmap(obj, obj_size);
 }

 static void userptr(int fd, uint64_t alloc)
 {
 	struct local_i915_gem_userptr userptr;
 	void *ptr;

 	igt_assert((alloc & 4095) == 0);

 	ptr = mmap(NULL, alloc,
 		   PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE,
 		   -1, 0);
 	igt_assert(ptr != (void *)-1);

 	memset(&userptr, 0, sizeof(userptr));
 	userptr.user_size = alloc;
 	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);

 	madvise(ptr, alloc, MADV_FREE);
 }

 static bool has_userptr(void)
 {
 	struct local_i915_gem_userptr userptr;
 	int fd = drm_open_driver(DRIVER_INTEL);
 	int err;

 	memset(&userptr, 0, sizeof(userptr));
 	userptr.user_size = 8192;
 	userptr.user_ptr = -4096;

 	err = 0;
 	if (drmIoctl(fd, LOCAL_IOCTL_I915_GEM_USERPTR, &userptr))
 		err = errno;

 	close(fd);

 	return err == EFAULT;
 }

 static void leak(int fd, uint64_t alloc)
 {
 	char *ptr;

 	ptr = mmap(NULL, alloc, PROT_READ | PROT_WRITE,
 		   MAP_ANON | MAP_PRIVATE | MAP_POPULATE,
 		   -1, 0);
 	if (ptr != (char *)-1)
 		return;

 	while (alloc) {
 		alloc -= 4096;
 		ptr[alloc] = 0;
 	}
 }

 #define SOLO 1
 #define USERPTR 2
 #define OOM 4

 static void run_test(int nchildren, uint64_t alloc,
 		     void (*func)(int, uint64_t), unsigned flags)
 {
 	const int timeout = flags & SOLO ? 1 : 20;

 	/* Each pass consumes alloc bytes and doesn't drop
 	 * its reference to object (i.e. calls
 	 * gem_madvise(DONTNEED) instead of gem_close()).
 	 * After nchildren passes we expect each process
 	 * to have enough objects to consume all of memory
 	 * if left unchecked.
 	 */

 	if (flags & SOLO)
 		nchildren = 1;

 	/* Background load */
 	if (flags & OOM) {
 		igt_fork(child, nchildren) {
 			igt_until_timeout(timeout) {
 				int fd = drm_open_driver(DRIVER_INTEL);
 				for (int pass = 0; pass < nchildren; pass++)
 					leak(fd, alloc);
 				close(fd);
 			}
 		}
 	}

 	if (flags & USERPTR) {
 		igt_require(has_userptr());
 		igt_fork(child, (nchildren + 1)/2) {
 			igt_until_timeout(timeout) {
 				int fd = drm_open_driver(DRIVER_INTEL);
 				for (int pass = 0; pass < nchildren; pass++)
 					userptr(fd, alloc);
 				close(fd);
 			}
 		}
 		nchildren = (nchildren + 1)/2;
 	}

 	/* Exercise major ioctls */
 	igt_fork(child, nchildren) {
 		igt_until_timeout(timeout) {
 			int fd = drm_open_driver(DRIVER_INTEL);
 			for (int pass = 0; pass < nchildren; pass++)
 				func(fd, alloc);
 			close(fd);
 		}
 	}
 	igt_waitchildren();
 }

 static void reclaim(unsigned engine, int timeout)
 {
 	const uint64_t timeout_100ms = 100000000LL;
 	int fd = drm_open_driver(DRIVER_INTEL);
 	int debugfs = igt_debugfs_dir(fd);
 	igt_spin_t *spin;
 	volatile uint32_t *shared;

 	shared = mmap(0, 4096, PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
 	igt_assert(shared != MAP_FAILED);

 	igt_fork(child, sysconf(_SC_NPROCESSORS_ONLN)) {
 		do {
 			igt_sysfs_printf(debugfs, "i915_drop_caches",
 					"%d", DROP_BOUND | DROP_UNBOUND);
 		} while (!*shared);
 	}

 	spin = igt_spin_batch_new(fd, .engine = engine);
 	igt_until_timeout(timeout) {
 		igt_spin_t *next = __igt_spin_batch_new(fd, .engine = engine);

 		igt_spin_batch_set_timeout(spin, timeout_100ms);
 		gem_sync(fd, spin->handle);

 		igt_spin_batch_free(fd, spin);
 		spin = next;
 	}
 	igt_spin_batch_free(fd, spin);

 	*shared = 1;
 	igt_waitchildren();

 	munmap((void *)shared, 4096);
 	close(debugfs);
 	close(fd);
 }

 igt_main
 {
 	const struct test {
 		const char *name;
 		void (*func)(int, uint64_t);
 	} tests[] = {
 		{ "get-pages", get_pages },
 		{ "pwrite", pwrite_ },
 		{ "pread", pread_ },
 		{ "mmap-gtt", mmap_gtt },
 		{ "mmap-cpu", mmap_cpu },
 		{ "execbuf1", execbuf1 },
 		{ "execbufN", execbufN },
 		{ "execbufX", execbufX },
 		{ "hang", hang },
 		{ NULL },
 	};
 	const struct mode {
 		const char *suffix;
 		unsigned flags;
 	} modes[] = {
 		{ "-sanitycheck", SOLO },
 		{ "", 0 },
 		{ "-userptr", USERPTR },
 		{ "-oom", USERPTR | OOM },
 		{ NULL },
 	};
 	uint64_t alloc_size = 0;
 	int num_processes = 0;

 	igt_skip_on_simulation();

 	igt_fixture {
 		uint64_t mem_size = intel_get_total_ram_mb();
 		unsigned int engine;
 		int fd;

 		/* Spawn enough processes to use all memory, but each only
 		 * uses half the available mappable aperture ~128MiB.
 		 * Individually the processes would be ok, but en masse
 		 * we expect the shrinker to start purging objects,
 		 * and possibly fail.
 		 */
 		alloc_size = gem_mappable_aperture_size() / 2;
 		num_processes = 1 + (mem_size / (alloc_size >> 20));

 		igt_info("Using %d processes and %'lluMiB per process\n",
 			 num_processes, (long long)(alloc_size >> 20));

 		intel_require_memory(num_processes, alloc_size,
 				     CHECK_SWAP | CHECK_RAM);

 		fd = drm_open_driver(DRIVER_INTEL);
 		igt_require_gem(fd);

 		nengine = 0;
 		for_each_engine(fd, engine)
 			engines[nengine++] = engine;
 		igt_require(nengine);

 		close(fd);
 	}

 	igt_subtest("reclaim")
 		reclaim(I915_EXEC_DEFAULT, 2);

 	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)
 				run_test(num_processes, alloc_size,
 					 t->func, m->flags);
 		}
 	}
 }
	/*
	* Copyright © 2016 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 gem_shrink.c
	*
	* Exercise the shrinker by overallocating GEM objects
	*/

	#include "igt.h"
	#include "igt_gt.h"
	#include "igt_debugfs.h"
	#include "igt_sysfs.h"

	#ifndef MADV_FREE
	#define MADV_FREE 8
	#endif

	static unsigned int engines[16], nengine;

	static void get_pages(int fd, uint64_t 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);
	}

	static void pwrite_(int fd, uint64_t alloc)
	{
	uint32_t tmp;
	uint32_t handle = gem_create(fd, alloc);
	for (int page = 0; page < alloc>>12; page++)
	gem_write(fd, handle, (page + page % 4095) & ~3, &tmp, 4);
	gem_madvise(fd, handle, I915_MADV_DONTNEED);
	}

	static void pread_(int fd, uint64_t alloc)
	{
	uint32_t tmp;
	uint32_t handle = gem_create(fd, alloc);
	for (int page = 0; page < alloc>>12; page++)
	gem_read(fd, handle, (page + page % 4095) & ~3, &tmp, 4);
	gem_madvise(fd, handle, I915_MADV_DONTNEED);
	}

	static void mmap_gtt(int fd, uint64_t alloc)
	{
	uint32_t handle = gem_create(fd, alloc);
	uint32_t *ptr = gem_mmap__gtt(fd, handle, alloc, PROT_WRITE);
	for (int page = 0; page < alloc>>12; page++)
	ptr[page<<10] = 0;
	munmap(ptr, alloc);
	gem_madvise(fd, handle, I915_MADV_DONTNEED);
	}

	static void mmap_cpu(int fd, uint64_t alloc)
	{
	uint32_t handle = gem_create(fd, alloc);
	uint32_t *ptr = gem_mmap__cpu(fd, handle, 0, alloc, PROT_WRITE);
	for (int page = 0; page < alloc>>12; page++)
	ptr[page<<10] = 0;
	munmap(ptr, alloc);
	gem_madvise(fd, handle, I915_MADV_DONTNEED);
	}

	static void execbuf1(int fd, uint64_t alloc)
	{
	const uint32_t bbe = MI_BATCH_BUFFER_END;
	struct drm_i915_gem_exec_object2 obj;
	struct drm_i915_gem_execbuffer2 execbuf;

	memset(&obj, 0, sizeof(obj));
	memset(&execbuf, 0, sizeof(execbuf));
	execbuf.buffers_ptr = to_user_pointer(&obj);
	execbuf.buffer_count = 1;

	obj.handle = gem_create(fd, alloc);
	gem_write(fd, obj.handle, 0, &bbe, sizeof(bbe));
	gem_execbuf(fd, &execbuf);
	gem_madvise(fd, obj.handle, I915_MADV_DONTNEED);
	}

	/* Since we want to trigger oom (SIGKILL), we don't want small allocations
	* to fail and generate a false error (SIGSEGV)! So we redirect allocations
	* though GEM objects, which should be much more likely to trigger oom. There
	* are still small allocations within the kernel, so still a small chance of
	* ENOMEM instead of a full oom.
	*/
	static void __gem_calloc(int fd, size_t count, size_t size, uint64_t out_size)
	{
	uint32_t handle;
	uint64_t total;
	void *ptr;

	total = count * size;
	total = (total + 4095) & -4096;

	handle = gem_create(fd, total);
	ptr = gem_mmap__cpu(fd, handle, 0, total, PROT_WRITE);
	gem_set_domain(fd, handle, I915_GEM_DOMAIN_CPU, I915_GEM_DOMAIN_CPU);
	gem_close(fd, handle);

	*out_size = total;
	return ptr;
	}

	static void execbufN(int fd, uint64_t alloc)
	{
	const uint32_t bbe = MI_BATCH_BUFFER_END;
	struct drm_i915_gem_exec_object2 *obj;
	struct drm_i915_gem_execbuffer2 execbuf;
	int count = alloc >> 20;
	uint64_t obj_size;

	obj = __gem_calloc(fd, alloc + 1, sizeof(*obj), &obj_size);
	memset(&execbuf, 0, sizeof(execbuf));

	obj[count].handle = gem_create(fd, 4096);
	gem_write(fd, obj[count].handle, 0, &bbe, sizeof(bbe));

	for (int i = 1; i <= count; i++) {
	int j = count - i;

	obj[j].handle = gem_create(fd, 1 << 20);
	execbuf.buffers_ptr = to_user_pointer(&obj[j]);
	execbuf.buffer_count = i + 1;
	gem_execbuf(fd, &execbuf);
	}

	for (int i = 0; i <= count; i++)
	gem_madvise(fd, obj[i].handle, I915_MADV_DONTNEED);
	munmap(obj, obj_size);
	}

	static void execbufX(int fd, uint64_t alloc)
	{
	const uint32_t bbe = MI_BATCH_BUFFER_END;
	struct drm_i915_gem_exec_object2 *obj;
	struct drm_i915_gem_execbuffer2 execbuf;
	int count = alloc >> 20;
	uint64_t obj_size;

	obj = __gem_calloc(fd, alloc + 1, sizeof(*obj), &obj_size);
	memset(&execbuf, 0, sizeof(execbuf));

	obj[count].handle = gem_create(fd, 4096);
	gem_write(fd, obj[count].handle, 0, &bbe, sizeof(bbe));

	for (int i = 1; i <= count; i++) {
	int j = count - i;

	obj[j+1].flags = 0;

	obj[j].handle = gem_create(fd, 1 << 20);
	obj[j].flags = EXEC_OBJECT_WRITE;

	execbuf.buffers_ptr = to_user_pointer(&obj[j]);
	execbuf.buffer_count = i + 1;
	execbuf.flags = engines[j % nengine];
	gem_execbuf(fd, &execbuf);
	}

	for (int i = 0; i <= count; i++)
	gem_madvise(fd, obj[i].handle, I915_MADV_DONTNEED);
	munmap(obj, obj_size);
	}

	static void hang(int fd, uint64_t alloc)
	{
	const uint32_t bbe = MI_BATCH_BUFFER_END;
	struct drm_i915_gem_exec_object2 *obj;
	struct drm_i915_gem_execbuffer2 execbuf;
	int count = alloc >> 20;
	uint64_t obj_size;

	obj = __gem_calloc(fd, alloc + 1, sizeof(*obj), &obj_size);
	memset(&execbuf, 0, sizeof(execbuf));

	obj[count].handle = gem_create(fd, 4096);
	gem_write(fd, obj[count].handle, 0, &bbe, sizeof(bbe));

	for (int i = 1; i <= count; i++) {
	int j = count - i;

	obj[j].handle = gem_create(fd, 1 << 20);
	execbuf.buffers_ptr = to_user_pointer(&obj[j]);
	execbuf.buffer_count = i + 1;
	gem_execbuf(fd, &execbuf);
	}

	gem_close(fd, igt_hang_ring(fd, 0).spin->handle);
	for (int i = 0; i <= count; i++)
	gem_madvise(fd, obj[i].handle, I915_MADV_DONTNEED);
	munmap(obj, obj_size);
	}

	static void userptr(int fd, uint64_t alloc)
	{
	struct local_i915_gem_userptr userptr;
	void *ptr;

	igt_assert((alloc & 4095) == 0);

	ptr = mmap(NULL, alloc,
	PROT_READ \| PROT_WRITE, MAP_ANON \| MAP_PRIVATE,
	-1, 0);
	igt_assert(ptr != (void *)-1);

	memset(&userptr, 0, sizeof(userptr));
	userptr.user_size = alloc;
	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);

	madvise(ptr, alloc, MADV_FREE);
	}

	static bool has_userptr(void)
	{
	struct local_i915_gem_userptr userptr;
	int fd = drm_open_driver(DRIVER_INTEL);
	int err;

	memset(&userptr, 0, sizeof(userptr));
	userptr.user_size = 8192;
	userptr.user_ptr = -4096;

	err = 0;
	if (drmIoctl(fd, LOCAL_IOCTL_I915_GEM_USERPTR, &userptr))
	err = errno;

	close(fd);

	return err == EFAULT;
	}

	static void leak(int fd, uint64_t alloc)
	{
	char *ptr;

	ptr = mmap(NULL, alloc, PROT_READ \| PROT_WRITE,
	MAP_ANON \| MAP_PRIVATE \| MAP_POPULATE,
	-1, 0);
	if (ptr != (char *)-1)
	return;

	while (alloc) {
	alloc -= 4096;
	ptr[alloc] = 0;
	}
	}

	#define SOLO 1
	#define USERPTR 2
	#define OOM 4

	static void run_test(int nchildren, uint64_t alloc,
	void (*func)(int, uint64_t), unsigned flags)
	{
	const int timeout = flags & SOLO ? 1 : 20;

	/* Each pass consumes alloc bytes and doesn't drop
	* its reference to object (i.e. calls
	* gem_madvise(DONTNEED) instead of gem_close()).
	* After nchildren passes we expect each process
	* to have enough objects to consume all of memory
	* if left unchecked.
	*/

	if (flags & SOLO)
	nchildren = 1;

	/* Background load */
	if (flags & OOM) {
	igt_fork(child, nchildren) {
	igt_until_timeout(timeout) {
	int fd = drm_open_driver(DRIVER_INTEL);
	for (int pass = 0; pass < nchildren; pass++)
	leak(fd, alloc);
	close(fd);
	}
	}
	}

	if (flags & USERPTR) {
	igt_require(has_userptr());
	igt_fork(child, (nchildren + 1)/2) {
	igt_until_timeout(timeout) {
	int fd = drm_open_driver(DRIVER_INTEL);
	for (int pass = 0; pass < nchildren; pass++)
	userptr(fd, alloc);
	close(fd);
	}
	}
	nchildren = (nchildren + 1)/2;
	}

	/* Exercise major ioctls */
	igt_fork(child, nchildren) {
	igt_until_timeout(timeout) {
	int fd = drm_open_driver(DRIVER_INTEL);
	for (int pass = 0; pass < nchildren; pass++)
	func(fd, alloc);
	close(fd);
	}
	}
	igt_waitchildren();
	}

	static void reclaim(unsigned engine, int timeout)
	{
	const uint64_t timeout_100ms = 100000000LL;
	int fd = drm_open_driver(DRIVER_INTEL);
	int debugfs = igt_debugfs_dir(fd);
	igt_spin_t *spin;
	volatile uint32_t *shared;

	shared = mmap(0, 4096, PROT_WRITE, MAP_SHARED \| MAP_ANON, -1, 0);
	igt_assert(shared != MAP_FAILED);

	igt_fork(child, sysconf(_SC_NPROCESSORS_ONLN)) {
	do {
	igt_sysfs_printf(debugfs, "i915_drop_caches",
	"%d", DROP_BOUND \| DROP_UNBOUND);
	} while (!*shared);
	}

	spin = igt_spin_batch_new(fd, .engine = engine);
	igt_until_timeout(timeout) {
	igt_spin_t *next = __igt_spin_batch_new(fd, .engine = engine);

	igt_spin_batch_set_timeout(spin, timeout_100ms);
	gem_sync(fd, spin->handle);

	igt_spin_batch_free(fd, spin);
	spin = next;
	}
	igt_spin_batch_free(fd, spin);

	*shared = 1;
	igt_waitchildren();

	munmap((void *)shared, 4096);
	close(debugfs);
	close(fd);
	}

	igt_main
	{
	const struct test {
	const char *name;
	void (*func)(int, uint64_t);
	} tests[] = {
	{ "get-pages", get_pages },
	{ "pwrite", pwrite_ },
	{ "pread", pread_ },
	{ "mmap-gtt", mmap_gtt },
	{ "mmap-cpu", mmap_cpu },
	{ "execbuf1", execbuf1 },
	{ "execbufN", execbufN },
	{ "execbufX", execbufX },
	{ "hang", hang },
	{ NULL },
	};
	const struct mode {
	const char *suffix;
	unsigned flags;
	} modes[] = {
	{ "-sanitycheck", SOLO },
	{ "", 0 },
	{ "-userptr", USERPTR },
	{ "-oom", USERPTR \| OOM },
	{ NULL },
	};
	uint64_t alloc_size = 0;
	int num_processes = 0;

	igt_skip_on_simulation();

	igt_fixture {
	uint64_t mem_size = intel_get_total_ram_mb();
	unsigned int engine;
	int fd;

	/* Spawn enough processes to use all memory, but each only
	* uses half the available mappable aperture ~128MiB.
	* Individually the processes would be ok, but en masse
	* we expect the shrinker to start purging objects,
	* and possibly fail.
	*/
	alloc_size = gem_mappable_aperture_size() / 2;
	num_processes = 1 + (mem_size / (alloc_size >> 20));

	igt_info("Using %d processes and %'lluMiB per process\n",
	num_processes, (long long)(alloc_size >> 20));

	intel_require_memory(num_processes, alloc_size,
	CHECK_SWAP \| CHECK_RAM);

	fd = drm_open_driver(DRIVER_INTEL);
	igt_require_gem(fd);

	nengine = 0;
	for_each_engine(fd, engine)
	engines[nengine++] = engine;
	igt_require(nengine);

	close(fd);
	}

	igt_subtest("reclaim")
	reclaim(I915_EXEC_DEFAULT, 2);

	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)
	run_test(num_processes, alloc_size,
	t->func, m->flags);
	}
	}
	}