1 // SPDX-License-Identifier: GPL-2.0
4 * Test module for stress and analyze performance of vmalloc allocator.
5 * (C) 2018 Uladzislau Rezki (Sony) <urezki@gmail.com>
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>
19 #define __param(type, name, init, msg) \
20 static type name = init; \
21 module_param(name, type, 0444); \
22 MODULE_PARM_DESC(name, msg) \
24 __param(bool, single_cpu_test, false,
25 "Use single first online CPU to run tests");
27 __param(bool, sequential_test_order
, false,
28 "Use sequential stress tests order");
30 __param(int, test_repeat_count
, 1,
31 "Set test repeat counter");
33 __param(int, test_loop_count
, 1000000,
34 "Set test loop counter");
36 __param(int, run_test_mask
, INT_MAX
,
37 "Set tests specified in the mask.\n\n"
38 "\t\tid: 1, name: fix_size_alloc_test\n"
39 "\t\tid: 2, name: full_fit_alloc_test\n"
40 "\t\tid: 4, name: long_busy_list_alloc_test\n"
41 "\t\tid: 8, name: random_size_alloc_test\n"
42 "\t\tid: 16, name: fix_align_alloc_test\n"
43 "\t\tid: 32, name: random_size_align_alloc_test\n"
44 "\t\tid: 64, name: align_shift_alloc_test\n"
45 "\t\tid: 128, name: pcpu_alloc_test\n"
46 /* Add a new test case description here. */
50 * Depends on single_cpu_test parameter. If it is true, then
51 * use first online CPU to trigger a test on, otherwise go with
54 static cpumask_t cpus_run_test_mask
= CPU_MASK_NONE
;
57 * Read write semaphore for synchronization of setup
58 * phase that is done in main thread and workers.
60 static DECLARE_RWSEM(prepare_for_test_rwsem
);
63 * Completion tracking for worker threads.
65 static DECLARE_COMPLETION(test_all_done_comp
);
66 static atomic_t test_n_undone
= ATOMIC_INIT(0);
69 test_report_one_done(void)
71 if (atomic_dec_and_test(&test_n_undone
))
72 complete(&test_all_done_comp
);
75 static int random_size_align_alloc_test(void)
77 unsigned long size
, align
, rnd
;
81 for (i
= 0; i
< test_loop_count
; i
++) {
82 get_random_bytes(&rnd
, sizeof(rnd
));
85 * Maximum 1024 pages, if PAGE_SIZE is 4096.
87 align
= 1 << (rnd
% 23);
92 size
= ((rnd
% 10) + 1) * PAGE_SIZE
;
94 ptr
= __vmalloc_node_range(size
, align
,
95 VMALLOC_START
, VMALLOC_END
,
96 GFP_KERNEL
| __GFP_ZERO
,
98 0, 0, __builtin_return_address(0));
110 * This test case is supposed to be failed.
112 static int align_shift_alloc_test(void)
118 for (i
= 0; i
< BITS_PER_LONG
; i
++) {
119 align
= ((unsigned long) 1) << i
;
121 ptr
= __vmalloc_node_range(PAGE_SIZE
, align
,
122 VMALLOC_START
, VMALLOC_END
,
123 GFP_KERNEL
| __GFP_ZERO
,
125 0, 0, __builtin_return_address(0));
136 static int fix_align_alloc_test(void)
141 for (i
= 0; i
< test_loop_count
; i
++) {
142 ptr
= __vmalloc_node_range(5 * PAGE_SIZE
,
144 VMALLOC_START
, VMALLOC_END
,
145 GFP_KERNEL
| __GFP_ZERO
,
147 0, 0, __builtin_return_address(0));
158 static int random_size_alloc_test(void)
164 for (i
= 0; i
< test_loop_count
; i
++) {
165 get_random_bytes(&n
, sizeof(i
));
168 p
= vmalloc(n
* PAGE_SIZE
);
180 static int long_busy_list_alloc_test(void)
187 ptr
= vmalloc(sizeof(void *) * 15000);
191 for (i
= 0; i
< 15000; i
++)
192 ptr
[i
] = vmalloc(1 * PAGE_SIZE
);
194 for (i
= 0; i
< test_loop_count
; i
++) {
195 ptr_1
= vmalloc(100 * PAGE_SIZE
);
199 ptr_2
= vmalloc(1 * PAGE_SIZE
);
205 *((__u8
*)ptr_1
) = 0;
206 *((__u8
*)ptr_2
) = 1;
216 for (i
= 0; i
< 15000; i
++)
223 static int full_fit_alloc_test(void)
225 void **ptr
, **junk_ptr
, *tmp
;
230 junk_length
= fls(num_online_cpus());
231 junk_length
*= (32 * 1024 * 1024 / PAGE_SIZE
);
233 ptr
= vmalloc(sizeof(void *) * junk_length
);
237 junk_ptr
= vmalloc(sizeof(void *) * junk_length
);
243 for (i
= 0; i
< junk_length
; i
++) {
244 ptr
[i
] = vmalloc(1 * PAGE_SIZE
);
245 junk_ptr
[i
] = vmalloc(1 * PAGE_SIZE
);
248 for (i
= 0; i
< junk_length
; i
++)
251 for (i
= 0; i
< test_loop_count
; i
++) {
252 tmp
= vmalloc(1 * PAGE_SIZE
);
265 for (i
= 0; i
< junk_length
; i
++)
274 static int fix_size_alloc_test(void)
279 for (i
= 0; i
< test_loop_count
; i
++) {
280 ptr
= vmalloc(3 * PAGE_SIZE
);
294 pcpu_alloc_test(void)
297 #ifndef CONFIG_NEED_PER_CPU_KM
298 void __percpu
**pcpu
;
302 pcpu
= vmalloc(sizeof(void __percpu
*) * 35000);
306 for (i
= 0; i
< 35000; i
++) {
309 get_random_bytes(&r
, sizeof(i
));
310 size
= (r
% (PAGE_SIZE
/ 4)) + 1;
315 get_random_bytes(&r
, sizeof(i
));
316 align
= 1 << ((i
% 11) + 1);
318 pcpu
[i
] = __alloc_percpu(size
, align
);
323 for (i
= 0; i
< 35000; i
++)
324 free_percpu(pcpu
[i
]);
331 struct test_case_desc
{
332 const char *test_name
;
333 int (*test_func
)(void);
336 static struct test_case_desc test_case_array
[] = {
337 { "fix_size_alloc_test", fix_size_alloc_test
},
338 { "full_fit_alloc_test", full_fit_alloc_test
},
339 { "long_busy_list_alloc_test", long_busy_list_alloc_test
},
340 { "random_size_alloc_test", random_size_alloc_test
},
341 { "fix_align_alloc_test", fix_align_alloc_test
},
342 { "random_size_align_alloc_test", random_size_align_alloc_test
},
343 { "align_shift_alloc_test", align_shift_alloc_test
},
344 { "pcpu_alloc_test", pcpu_alloc_test
},
345 /* Add a new test case here. */
348 struct test_case_data
{
354 /* Split it to get rid of: WARNING: line over 80 characters */
355 static struct test_case_data
356 per_cpu_test_data
[NR_CPUS
][ARRAY_SIZE(test_case_array
)];
358 static struct test_driver
{
359 struct task_struct
*task
;
363 } per_cpu_test_driver
[NR_CPUS
];
365 static void shuffle_array(int *arr
, int n
)
370 for (i
= n
- 1; i
> 0; i
--) {
371 get_random_bytes(&rnd
, sizeof(rnd
));
383 static int test_func(void *private)
385 struct test_driver
*t
= private;
386 int random_array
[ARRAY_SIZE(test_case_array
)];
391 if (set_cpus_allowed_ptr(current
, cpumask_of(t
->cpu
)) < 0)
392 pr_err("Failed to set affinity to %d CPU\n", t
->cpu
);
394 for (i
= 0; i
< ARRAY_SIZE(test_case_array
); i
++)
397 if (!sequential_test_order
)
398 shuffle_array(random_array
, ARRAY_SIZE(test_case_array
));
401 * Block until initialization is done.
403 down_read(&prepare_for_test_rwsem
);
405 t
->start
= get_cycles();
406 for (i
= 0; i
< ARRAY_SIZE(test_case_array
); i
++) {
407 index
= random_array
[i
];
410 * Skip tests if run_test_mask has been specified.
412 if (!((run_test_mask
& (1 << index
)) >> index
))
416 for (j
= 0; j
< test_repeat_count
; j
++) {
417 if (!test_case_array
[index
].test_func())
418 per_cpu_test_data
[t
->cpu
][index
].test_passed
++;
420 per_cpu_test_data
[t
->cpu
][index
].test_failed
++;
424 * Take an average time that test took.
426 delta
= (u64
) ktime_us_delta(ktime_get(), kt
);
427 do_div(delta
, (u32
) test_repeat_count
);
429 per_cpu_test_data
[t
->cpu
][index
].time
= delta
;
431 t
->stop
= get_cycles();
433 up_read(&prepare_for_test_rwsem
);
434 test_report_one_done();
437 * Wait for the kthread_stop() call.
439 while (!kthread_should_stop())
446 init_test_configurtion(void)
449 * Reset all data of all CPUs.
451 memset(per_cpu_test_data
, 0, sizeof(per_cpu_test_data
));
454 cpumask_set_cpu(cpumask_first(cpu_online_mask
),
455 &cpus_run_test_mask
);
457 cpumask_and(&cpus_run_test_mask
, cpu_online_mask
,
460 if (test_repeat_count
<= 0)
461 test_repeat_count
= 1;
463 if (test_loop_count
<= 0)
467 static void do_concurrent_test(void)
472 * Set some basic configurations plus sanity check.
474 init_test_configurtion();
477 * Put on hold all workers.
479 down_write(&prepare_for_test_rwsem
);
481 for_each_cpu(cpu
, &cpus_run_test_mask
) {
482 struct test_driver
*t
= &per_cpu_test_driver
[cpu
];
485 t
->task
= kthread_run(test_func
, t
, "vmalloc_test/%d", cpu
);
487 if (!IS_ERR(t
->task
))
489 atomic_inc(&test_n_undone
);
491 pr_err("Failed to start kthread for %d CPU\n", cpu
);
495 * Now let the workers do their job.
497 up_write(&prepare_for_test_rwsem
);
500 * Sleep quiet until all workers are done with 1 second
501 * interval. Since the test can take a lot of time we
502 * can run into a stack trace of the hung task. That is
503 * why we go with completion_timeout and HZ value.
506 ret
= wait_for_completion_timeout(&test_all_done_comp
, HZ
);
509 for_each_cpu(cpu
, &cpus_run_test_mask
) {
510 struct test_driver
*t
= &per_cpu_test_driver
[cpu
];
513 if (!IS_ERR(t
->task
))
514 kthread_stop(t
->task
);
516 for (i
= 0; i
< ARRAY_SIZE(test_case_array
); i
++) {
517 if (!((run_test_mask
& (1 << i
)) >> i
))
521 "Summary: %s passed: %d failed: %d repeat: %d loops: %d avg: %llu usec\n",
522 test_case_array
[i
].test_name
,
523 per_cpu_test_data
[cpu
][i
].test_passed
,
524 per_cpu_test_data
[cpu
][i
].test_failed
,
525 test_repeat_count
, test_loop_count
,
526 per_cpu_test_data
[cpu
][i
].time
);
529 pr_info("All test took CPU%d=%lu cycles\n",
530 cpu
, t
->stop
- t
->start
);
534 static int vmalloc_test_init(void)
536 do_concurrent_test();
537 return -EAGAIN
; /* Fail will directly unload the module */
540 static void vmalloc_test_exit(void)
544 module_init(vmalloc_test_init
)
545 module_exit(vmalloc_test_exit
)
547 MODULE_LICENSE("GPL");
548 MODULE_AUTHOR("Uladzislau Rezki");
549 MODULE_DESCRIPTION("vmalloc test module");