1// SPDX-License-Identifier: GPL-2.0
  2
  3/*
  4 * Test module for stress and analyze performance of vmalloc allocator.
  5 * (C) 2018 Uladzislau Rezki (Sony) <urezki@gmail.com>
  6 */
  7#include <linux/init.h>
  8#include <linux/kernel.h>
  9#include <linux/module.h>
 10#include <linux/vmalloc.h>
 11#include <linux/random.h>
 12#include <linux/kthread.h>
 13#include <linux/moduleparam.h>
 14#include <linux/completion.h>
 15#include <linux/delay.h>
 16#include <linux/rwsem.h>
 17#include <linux/mm.h>
 18#include <linux/rcupdate.h>
 19#include <linux/slab.h>
 20
 21#define __param(type, name, init, msg)		\
 22	static type name = init;				\
 23	module_param(name, type, 0444);			\
 24	MODULE_PARM_DESC(name, msg)				\
 25
 26__param(bool, single_cpu_test, false,
 27	"Use single first online CPU to run tests");
 28
 29__param(bool, sequential_test_order, false,
 30	"Use sequential stress tests order");
 31
 32__param(int, test_repeat_count, 1,
 33	"Set test repeat counter");
 34
 35__param(int, test_loop_count, 1000000,
 36	"Set test loop counter");
 37
 38__param(int, run_test_mask, INT_MAX,
 39	"Set tests specified in the mask.\n\n"
 40		"\t\tid: 1,    name: fix_size_alloc_test\n"
 41		"\t\tid: 2,    name: full_fit_alloc_test\n"
 42		"\t\tid: 4,    name: long_busy_list_alloc_test\n"
 43		"\t\tid: 8,    name: random_size_alloc_test\n"
 44		"\t\tid: 16,   name: fix_align_alloc_test\n"
 45		"\t\tid: 32,   name: random_size_align_alloc_test\n"
 46		"\t\tid: 64,   name: align_shift_alloc_test\n"
 47		"\t\tid: 128,  name: pcpu_alloc_test\n"
 48		"\t\tid: 256,  name: kvfree_rcu_1_arg_vmalloc_test\n"
 49		"\t\tid: 512,  name: kvfree_rcu_2_arg_vmalloc_test\n"
 50		"\t\tid: 1024, name: kvfree_rcu_1_arg_slab_test\n"
 51		"\t\tid: 2048, name: kvfree_rcu_2_arg_slab_test\n"
 52		/* Add a new test case description here. */
 53);
 54
 55/*
 56 * Depends on single_cpu_test parameter. If it is true, then
 57 * use first online CPU to trigger a test on, otherwise go with
 58 * all online CPUs.
 59 */
 60static cpumask_t cpus_run_test_mask = CPU_MASK_NONE;
 61
 62/*
 63 * Read write semaphore for synchronization of setup
 64 * phase that is done in main thread and workers.
 65 */
 66static DECLARE_RWSEM(prepare_for_test_rwsem);
 67
 68/*
 69 * Completion tracking for worker threads.
 70 */
 71static DECLARE_COMPLETION(test_all_done_comp);
 72static atomic_t test_n_undone = ATOMIC_INIT(0);
 73
 74static inline void
 75test_report_one_done(void)
 76{
 77	if (atomic_dec_and_test(&test_n_undone))
 78		complete(&test_all_done_comp);
 79}
 80
 81static int random_size_align_alloc_test(void)
 82{
 83	unsigned long size, align, rnd;
 84	void *ptr;
 85	int i;
 86
 87	for (i = 0; i < test_loop_count; i++) {
 88		get_random_bytes(&rnd, sizeof(rnd));
 89
 90		/*
 91		 * Maximum 1024 pages, if PAGE_SIZE is 4096.
 92		 */
 93		align = 1 << (rnd % 23);
 94
 95		/*
 96		 * Maximum 10 pages.
 97		 */
 98		size = ((rnd % 10) + 1) * PAGE_SIZE;
 99
100		ptr = __vmalloc_node(size, align, GFP_KERNEL | __GFP_ZERO, 0,
101				__builtin_return_address(0));
102		if (!ptr)
103			return -1;
104
105		vfree(ptr);
106	}
107
108	return 0;
109}
110
111/*
112 * This test case is supposed to be failed.
113 */
114static int align_shift_alloc_test(void)
115{
116	unsigned long align;
117	void *ptr;
118	int i;
119
120	for (i = 0; i < BITS_PER_LONG; i++) {
121		align = ((unsigned long) 1) << i;
122
123		ptr = __vmalloc_node(PAGE_SIZE, align, GFP_KERNEL|__GFP_ZERO, 0,
124				__builtin_return_address(0));
125		if (!ptr)
126			return -1;
127
128		vfree(ptr);
129	}
130
131	return 0;
132}
133
134static int fix_align_alloc_test(void)
135{
136	void *ptr;
137	int i;
138
139	for (i = 0; i < test_loop_count; i++) {
140		ptr = __vmalloc_node(5 * PAGE_SIZE, THREAD_ALIGN << 1,
141				GFP_KERNEL | __GFP_ZERO, 0,
142				__builtin_return_address(0));
143		if (!ptr)
144			return -1;
145
146		vfree(ptr);
147	}
148
149	return 0;
150}
151
152static int random_size_alloc_test(void)
153{
154	unsigned int n;
155	void *p;
156	int i;
157
158	for (i = 0; i < test_loop_count; i++) {
159		get_random_bytes(&n, sizeof(i));
160		n = (n % 100) + 1;
161
162		p = vmalloc(n * PAGE_SIZE);
163
164		if (!p)
165			return -1;
166
167		*((__u8 *)p) = 1;
168		vfree(p);
169	}
170
171	return 0;
172}
173
174static int long_busy_list_alloc_test(void)
175{
176	void *ptr_1, *ptr_2;
177	void **ptr;
178	int rv = -1;
179	int i;
180
181	ptr = vmalloc(sizeof(void *) * 15000);
182	if (!ptr)
183		return rv;
184
185	for (i = 0; i < 15000; i++)
186		ptr[i] = vmalloc(1 * PAGE_SIZE);
187
188	for (i = 0; i < test_loop_count; i++) {
189		ptr_1 = vmalloc(100 * PAGE_SIZE);
190		if (!ptr_1)
191			goto leave;
192
193		ptr_2 = vmalloc(1 * PAGE_SIZE);
194		if (!ptr_2) {
195			vfree(ptr_1);
196			goto leave;
197		}
198
199		*((__u8 *)ptr_1) = 0;
200		*((__u8 *)ptr_2) = 1;
201
202		vfree(ptr_1);
203		vfree(ptr_2);
204	}
205
206	/*  Success */
207	rv = 0;
208
209leave:
210	for (i = 0; i < 15000; i++)
211		vfree(ptr[i]);
212
213	vfree(ptr);
214	return rv;
215}
216
217static int full_fit_alloc_test(void)
218{
219	void **ptr, **junk_ptr, *tmp;
220	int junk_length;
221	int rv = -1;
222	int i;
223
224	junk_length = fls(num_online_cpus());
225	junk_length *= (32 * 1024 * 1024 / PAGE_SIZE);
226
227	ptr = vmalloc(sizeof(void *) * junk_length);
228	if (!ptr)
229		return rv;
230
231	junk_ptr = vmalloc(sizeof(void *) * junk_length);
232	if (!junk_ptr) {
233		vfree(ptr);
234		return rv;
235	}
236
237	for (i = 0; i < junk_length; i++) {
238		ptr[i] = vmalloc(1 * PAGE_SIZE);
239		junk_ptr[i] = vmalloc(1 * PAGE_SIZE);
240	}
241
242	for (i = 0; i < junk_length; i++)
243		vfree(junk_ptr[i]);
244
245	for (i = 0; i < test_loop_count; i++) {
246		tmp = vmalloc(1 * PAGE_SIZE);
247
248		if (!tmp)
249			goto error;
250
251		*((__u8 *)tmp) = 1;
252		vfree(tmp);
253	}
254
255	/* Success */
256	rv = 0;
257
258error:
259	for (i = 0; i < junk_length; i++)
260		vfree(ptr[i]);
261
262	vfree(ptr);
263	vfree(junk_ptr);
264
265	return rv;
266}
267
268static int fix_size_alloc_test(void)
269{
270	void *ptr;
271	int i;
272
273	for (i = 0; i < test_loop_count; i++) {
274		ptr = vmalloc(3 * PAGE_SIZE);
275
276		if (!ptr)
277			return -1;
278
279		*((__u8 *)ptr) = 0;
280
281		vfree(ptr);
282	}
283
284	return 0;
285}
286
287static int
288pcpu_alloc_test(void)
289{
290	int rv = 0;
291#ifndef CONFIG_NEED_PER_CPU_KM
292	void __percpu **pcpu;
293	size_t size, align;
294	int i;
295
296	pcpu = vmalloc(sizeof(void __percpu *) * 35000);
297	if (!pcpu)
298		return -1;
299
300	for (i = 0; i < 35000; i++) {
301		unsigned int r;
302
303		get_random_bytes(&r, sizeof(i));
304		size = (r % (PAGE_SIZE / 4)) + 1;
305
306		/*
307		 * Maximum PAGE_SIZE
308		 */
309		get_random_bytes(&r, sizeof(i));
310		align = 1 << ((i % 11) + 1);
311
312		pcpu[i] = __alloc_percpu(size, align);
313		if (!pcpu[i])
314			rv = -1;
315	}
316
317	for (i = 0; i < 35000; i++)
318		free_percpu(pcpu[i]);
319
320	vfree(pcpu);
321#endif
322	return rv;
323}
324
325struct test_kvfree_rcu {
326	struct rcu_head rcu;
327	unsigned char array[20];
328};
329
330static int
331kvfree_rcu_1_arg_vmalloc_test(void)
332{
333	struct test_kvfree_rcu *p;
334	int i;
335
336	for (i = 0; i < test_loop_count; i++) {
337		p = vmalloc(1 * PAGE_SIZE);
338		if (!p)
339			return -1;
340
341		p->array[0] = 'a';
342		kvfree_rcu(p);
343	}
344
345	return 0;
346}
347
348static int
349kvfree_rcu_2_arg_vmalloc_test(void)
350{
351	struct test_kvfree_rcu *p;
352	int i;
353
354	for (i = 0; i < test_loop_count; i++) {
355		p = vmalloc(1 * PAGE_SIZE);
356		if (!p)
357			return -1;
358
359		p->array[0] = 'a';
360		kvfree_rcu(p, rcu);
361	}
362
363	return 0;
364}
365
366static int
367kvfree_rcu_1_arg_slab_test(void)
368{
369	struct test_kvfree_rcu *p;
370	int i;
371
372	for (i = 0; i < test_loop_count; i++) {
373		p = kmalloc(sizeof(*p), GFP_KERNEL);
374		if (!p)
375			return -1;
376
377		p->array[0] = 'a';
378		kvfree_rcu(p);
379	}
380
381	return 0;
382}
383
384static int
385kvfree_rcu_2_arg_slab_test(void)
386{
387	struct test_kvfree_rcu *p;
388	int i;
389
390	for (i = 0; i < test_loop_count; i++) {
391		p = kmalloc(sizeof(*p), GFP_KERNEL);
392		if (!p)
393			return -1;
394
395		p->array[0] = 'a';
396		kvfree_rcu(p, rcu);
397	}
398
399	return 0;
400}
401
402struct test_case_desc {
403	const char *test_name;
404	int (*test_func)(void);
405};
406
407static struct test_case_desc test_case_array[] = {
408	{ "fix_size_alloc_test", fix_size_alloc_test },
409	{ "full_fit_alloc_test", full_fit_alloc_test },
410	{ "long_busy_list_alloc_test", long_busy_list_alloc_test },
411	{ "random_size_alloc_test", random_size_alloc_test },
412	{ "fix_align_alloc_test", fix_align_alloc_test },
413	{ "random_size_align_alloc_test", random_size_align_alloc_test },
414	{ "align_shift_alloc_test", align_shift_alloc_test },
415	{ "pcpu_alloc_test", pcpu_alloc_test },
416	{ "kvfree_rcu_1_arg_vmalloc_test", kvfree_rcu_1_arg_vmalloc_test },
417	{ "kvfree_rcu_2_arg_vmalloc_test", kvfree_rcu_2_arg_vmalloc_test },
418	{ "kvfree_rcu_1_arg_slab_test", kvfree_rcu_1_arg_slab_test },
419	{ "kvfree_rcu_2_arg_slab_test", kvfree_rcu_2_arg_slab_test },
420	/* Add a new test case here. */
421};
422
423struct test_case_data {
424	int test_failed;
425	int test_passed;
426	u64 time;
427};
428
429/* Split it to get rid of: WARNING: line over 80 characters */
430static struct test_case_data
431	per_cpu_test_data[NR_CPUS][ARRAY_SIZE(test_case_array)];
432
433static struct test_driver {
434	struct task_struct *task;
435	unsigned long start;
436	unsigned long stop;
437	int cpu;
438} per_cpu_test_driver[NR_CPUS];
439
440static void shuffle_array(int *arr, int n)
441{
442	unsigned int rnd;
443	int i, j, x;
444
445	for (i = n - 1; i > 0; i--)  {
446		get_random_bytes(&rnd, sizeof(rnd));
447
448		/* Cut the range. */
449		j = rnd % i;
450
451		/* Swap indexes. */
452		x = arr[i];
453		arr[i] = arr[j];
454		arr[j] = x;
455	}
456}
457
458static int test_func(void *private)
459{
460	struct test_driver *t = private;
461	int random_array[ARRAY_SIZE(test_case_array)];
462	int index, i, j;
463	ktime_t kt;
464	u64 delta;
465
466	if (set_cpus_allowed_ptr(current, cpumask_of(t->cpu)) < 0)
467		pr_err("Failed to set affinity to %d CPU\n", t->cpu);
468
469	for (i = 0; i < ARRAY_SIZE(test_case_array); i++)
470		random_array[i] = i;
471
472	if (!sequential_test_order)
473		shuffle_array(random_array, ARRAY_SIZE(test_case_array));
474
475	/*
476	 * Block until initialization is done.
477	 */
478	down_read(&prepare_for_test_rwsem);
479
480	t->start = get_cycles();
481	for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
482		index = random_array[i];
483
484		/*
485		 * Skip tests if run_test_mask has been specified.
486		 */
487		if (!((run_test_mask & (1 << index)) >> index))
488			continue;
489
490		kt = ktime_get();
491		for (j = 0; j < test_repeat_count; j++) {
492			if (!test_case_array[index].test_func())
493				per_cpu_test_data[t->cpu][index].test_passed++;
494			else
495				per_cpu_test_data[t->cpu][index].test_failed++;
496		}
497
498		/*
499		 * Take an average time that test took.
500		 */
501		delta = (u64) ktime_us_delta(ktime_get(), kt);
502		do_div(delta, (u32) test_repeat_count);
503
504		per_cpu_test_data[t->cpu][index].time = delta;
505	}
506	t->stop = get_cycles();
507
508	up_read(&prepare_for_test_rwsem);
509	test_report_one_done();
510
511	/*
512	 * Wait for the kthread_stop() call.
513	 */
514	while (!kthread_should_stop())
515		msleep(10);
516
517	return 0;
518}
519
520static void
521init_test_configurtion(void)
522{
523	/*
524	 * Reset all data of all CPUs.
525	 */
526	memset(per_cpu_test_data, 0, sizeof(per_cpu_test_data));
527
528	if (single_cpu_test)
529		cpumask_set_cpu(cpumask_first(cpu_online_mask),
530			&cpus_run_test_mask);
531	else
532		cpumask_and(&cpus_run_test_mask, cpu_online_mask,
533			cpu_online_mask);
534
535	if (test_repeat_count <= 0)
536		test_repeat_count = 1;
537
538	if (test_loop_count <= 0)
539		test_loop_count = 1;
540}
541
542static void do_concurrent_test(void)
543{
544	int cpu, ret;
545
546	/*
547	 * Set some basic configurations plus sanity check.
548	 */
549	init_test_configurtion();
550
551	/*
552	 * Put on hold all workers.
553	 */
554	down_write(&prepare_for_test_rwsem);
555
556	for_each_cpu(cpu, &cpus_run_test_mask) {
557		struct test_driver *t = &per_cpu_test_driver[cpu];
558
559		t->cpu = cpu;
560		t->task = kthread_run(test_func, t, "vmalloc_test/%d", cpu);
561
562		if (!IS_ERR(t->task))
563			/* Success. */
564			atomic_inc(&test_n_undone);
565		else
566			pr_err("Failed to start kthread for %d CPU\n", cpu);
567	}
568
569	/*
570	 * Now let the workers do their job.
571	 */
572	up_write(&prepare_for_test_rwsem);
573
574	/*
575	 * Sleep quiet until all workers are done with 1 second
576	 * interval. Since the test can take a lot of time we
577	 * can run into a stack trace of the hung task. That is
578	 * why we go with completion_timeout and HZ value.
579	 */
580	do {
581		ret = wait_for_completion_timeout(&test_all_done_comp, HZ);
582	} while (!ret);
583
584	for_each_cpu(cpu, &cpus_run_test_mask) {
585		struct test_driver *t = &per_cpu_test_driver[cpu];
586		int i;
587
588		if (!IS_ERR(t->task))
589			kthread_stop(t->task);
590
591		for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
592			if (!((run_test_mask & (1 << i)) >> i))
593				continue;
594
595			pr_info(
596				"Summary: %s passed: %d failed: %d repeat: %d loops: %d avg: %llu usec\n",
597				test_case_array[i].test_name,
598				per_cpu_test_data[cpu][i].test_passed,
599				per_cpu_test_data[cpu][i].test_failed,
600				test_repeat_count, test_loop_count,
601				per_cpu_test_data[cpu][i].time);
602		}
603
604		pr_info("All test took CPU%d=%lu cycles\n",
605			cpu, t->stop - t->start);
606	}
607}
608
609static int vmalloc_test_init(void)
610{
611	do_concurrent_test();
612	return -EAGAIN; /* Fail will directly unload the module */
613}
614
615static void vmalloc_test_exit(void)
616{
617}
618
619module_init(vmalloc_test_init)
620module_exit(vmalloc_test_exit)
621
622MODULE_LICENSE("GPL");
623MODULE_AUTHOR("Uladzislau Rezki");
624MODULE_DESCRIPTION("vmalloc test module");