// SPDX-License-Identifier: GPL-2.0 /* * Test module for stress and analyze performance of vmalloc allocator. * (C) 2018 Uladzislau Rezki (Sony) <urezki@gmail.com> */ #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/vmalloc.h> #include <linux/random.h> #include <linux/kthread.h> #include <linux/moduleparam.h> #include <linux/completion.h> #include <linux/delay.h> #include <linux/rwsem.h> #include <linux/mm.h> #include <linux/rcupdate.h> #include <linux/slab.h> #define __param(type, name, init, msg) \ static type name = init; \ module_param(name, type, 0444); \ MODULE_PARM_DESC(name, msg) \ __param(int, nr_threads, 0, "Number of workers to perform tests(min: 1 max: USHRT_MAX)"); __param(bool, sequential_test_order, false, "Use sequential stress tests order"); __param(int, test_repeat_count, 1, "Set test repeat counter"); __param(int, test_loop_count, 1000000, "Set test loop counter"); __param(int, nr_pages, 0, "Set number of pages for fix_size_alloc_test(default: 1)"); __param(int, run_test_mask, INT_MAX, "Set tests specified in the mask.\n\n" "\t\tid: 1, name: fix_size_alloc_test\n" "\t\tid: 2, name: full_fit_alloc_test\n" "\t\tid: 4, name: long_busy_list_alloc_test\n" "\t\tid: 8, name: random_size_alloc_test\n" "\t\tid: 16, name: fix_align_alloc_test\n" "\t\tid: 32, name: random_size_align_alloc_test\n" "\t\tid: 64, name: align_shift_alloc_test\n" "\t\tid: 128, name: pcpu_alloc_test\n" "\t\tid: 256, name: kvfree_rcu_1_arg_vmalloc_test\n" "\t\tid: 512, name: kvfree_rcu_2_arg_vmalloc_test\n" /* Add a new test case description here. */ ); /* * Read write semaphore for synchronization of setup * phase that is done in main thread and workers. */ static DECLARE_RWSEM(prepare_for_test_rwsem); /* * Completion tracking for worker threads. */ static DECLARE_COMPLETION(test_all_done_comp); static atomic_t test_n_undone = ATOMIC_INIT(0); static inline void test_report_one_done(void) { if (atomic_dec_and_test(&test_n_undone)) complete(&test_all_done_comp); } static int random_size_align_alloc_test(void) { unsigned long size, align, rnd; void *ptr; int i; for (i = 0; i < test_loop_count; i++) { get_random_bytes(&rnd, sizeof(rnd)); /* * Maximum 1024 pages, if PAGE_SIZE is 4096. */ align = 1 << (rnd % 23); /* * Maximum 10 pages. */ size = ((rnd % 10) + 1) * PAGE_SIZE; ptr = __vmalloc_node(size, align, GFP_KERNEL | __GFP_ZERO, 0, __builtin_return_address(0)); if (!ptr) return -1; vfree(ptr); } return 0; } /* * This test case is supposed to be failed. */ static int align_shift_alloc_test(void) { unsigned long align; void *ptr; int i; for (i = 0; i < BITS_PER_LONG; i++) { align = ((unsigned long) 1) << i; ptr = __vmalloc_node(PAGE_SIZE, align, GFP_KERNEL|__GFP_ZERO, 0, __builtin_return_address(0)); if (!ptr) return -1; vfree(ptr); } return 0; } static int fix_align_alloc_test(void) { void *ptr; int i; for (i = 0; i < test_loop_count; i++) { ptr = __vmalloc_node(5 * PAGE_SIZE, THREAD_ALIGN << 1, GFP_KERNEL | __GFP_ZERO, 0, __builtin_return_address(0)); if (!ptr) return -1; vfree(ptr); } return 0; } static int random_size_alloc_test(void) { unsigned int n; void *p; int i; for (i = 0; i < test_loop_count; i++) { get_random_bytes(&n, sizeof(i)); n = (n % 100) + 1; p = vmalloc(n * PAGE_SIZE); if (!p) return -1; *((__u8 *)p) = 1; vfree(p); } return 0; } static int long_busy_list_alloc_test(void) { void *ptr_1, *ptr_2; void **ptr; int rv = -1; int i; ptr = vmalloc(sizeof(void *) * 15000); if (!ptr) return rv; for (i = 0; i < 15000; i++) ptr[i] = vmalloc(1 * PAGE_SIZE); for (i = 0; i < test_loop_count; i++) { ptr_1 = vmalloc(100 * PAGE_SIZE); if (!ptr_1) goto leave; ptr_2 = vmalloc(1 * PAGE_SIZE); if (!ptr_2) { vfree(ptr_1); goto leave; } *((__u8 *)ptr_1) = 0; *((__u8 *)ptr_2) = 1; vfree(ptr_1); vfree(ptr_2); } /* Success */ rv = 0; leave: for (i = 0; i < 15000; i++) vfree(ptr[i]); vfree(ptr); return rv; } static int full_fit_alloc_test(void) { void **ptr, **junk_ptr, *tmp; int junk_length; int rv = -1; int i; junk_length = fls(num_online_cpus()); junk_length *= (32 * 1024 * 1024 / PAGE_SIZE); ptr = vmalloc(sizeof(void *) * junk_length); if (!ptr) return rv; junk_ptr = vmalloc(sizeof(void *) * junk_length); if (!junk_ptr) { vfree(ptr); return rv; } for (i = 0; i < junk_length; i++) { ptr[i] = vmalloc(1 * PAGE_SIZE); junk_ptr[i] = vmalloc(1 * PAGE_SIZE); } for (i = 0; i < junk_length; i++) vfree(junk_ptr[i]); for (i = 0; i < test_loop_count; i++) { tmp = vmalloc(1 * PAGE_SIZE); if (!tmp) goto error; *((__u8 *)tmp) = 1; vfree(tmp); } /* Success */ rv = 0; error: for (i = 0; i < junk_length; i++) vfree(ptr[i]); vfree(ptr); vfree(junk_ptr); return rv; } static int fix_size_alloc_test(void) { void *ptr; int i; for (i = 0; i < test_loop_count; i++) { ptr = vmalloc((nr_pages > 0 ? nr_pages:1) * PAGE_SIZE); if (!ptr) return -1; *((__u8 *)ptr) = 0; vfree(ptr); } return 0; } static int pcpu_alloc_test(void) { int rv = 0; #ifndef CONFIG_NEED_PER_CPU_KM void __percpu **pcpu; size_t size, align; int i; pcpu = vmalloc(sizeof(void __percpu *) * 35000); if (!pcpu) return -1; for (i = 0; i < 35000; i++) { unsigned int r; get_random_bytes(&r, sizeof(i)); size = (r % (PAGE_SIZE / 4)) + 1; /* * Maximum PAGE_SIZE */ get_random_bytes(&r, sizeof(i)); align = 1 << ((i % 11) + 1); pcpu[i] = __alloc_percpu(size, align); if (!pcpu[i]) rv = -1; } for (i = 0; i < 35000; i++) free_percpu(pcpu[i]); vfree(pcpu); #endif return rv; } struct test_kvfree_rcu { struct rcu_head rcu; unsigned char array[20]; }; static int kvfree_rcu_1_arg_vmalloc_test(void) { struct test_kvfree_rcu *p; int i; for (i = 0; i < test_loop_count; i++) { p = vmalloc(1 * PAGE_SIZE); if (!p) return -1; p->array[0] = 'a'; kvfree_rcu(p); } return 0; } static int kvfree_rcu_2_arg_vmalloc_test(void) { struct test_kvfree_rcu *p; int i; for (i = 0; i < test_loop_count; i++) { p = vmalloc(1 * PAGE_SIZE); if (!p) return -1; p->array[0] = 'a'; kvfree_rcu(p, rcu); } return 0; } struct test_case_desc { const char *test_name; int (*test_func)(void); }; static struct test_case_desc test_case_array[] = { { "fix_size_alloc_test", fix_size_alloc_test }, { "full_fit_alloc_test", full_fit_alloc_test }, { "long_busy_list_alloc_test", long_busy_list_alloc_test }, { "random_size_alloc_test", random_size_alloc_test }, { "fix_align_alloc_test", fix_align_alloc_test }, { "random_size_align_alloc_test", random_size_align_alloc_test }, { "align_shift_alloc_test", align_shift_alloc_test }, { "pcpu_alloc_test", pcpu_alloc_test }, { "kvfree_rcu_1_arg_vmalloc_test", kvfree_rcu_1_arg_vmalloc_test }, { "kvfree_rcu_2_arg_vmalloc_test", kvfree_rcu_2_arg_vmalloc_test }, /* Add a new test case here. */ }; struct test_case_data { int test_failed; int test_passed; u64 time; }; static struct test_driver { struct task_struct *task; struct test_case_data data[ARRAY_SIZE(test_case_array)]; unsigned long start; unsigned long stop; } *tdriver; static void shuffle_array(int *arr, int n) { unsigned int rnd; int i, j; for (i = n - 1; i > 0; i--) { get_random_bytes(&rnd, sizeof(rnd)); /* Cut the range. */ j = rnd % i; /* Swap indexes. */ swap(arr[i], arr[j]); } } static int test_func(void *private) { struct test_driver *t = private; int random_array[ARRAY_SIZE(test_case_array)]; int index, i, j; ktime_t kt; u64 delta; for (i = 0; i < ARRAY_SIZE(test_case_array); i++) random_array[i] = i; if (!sequential_test_order) shuffle_array(random_array, ARRAY_SIZE(test_case_array)); /* * Block until initialization is done. */ down_read(&prepare_for_test_rwsem); t->start = get_cycles(); for (i = 0; i < ARRAY_SIZE(test_case_array); i++) { index = random_array[i]; /* * Skip tests if run_test_mask has been specified. */ if (!((run_test_mask & (1 << index)) >> index)) continue; kt = ktime_get(); for (j = 0; j < test_repeat_count; j++) { if (!test_case_array[index].test_func()) t->data[index].test_passed++; else t->data[index].test_failed++; } /* * Take an average time that test took. */ delta = (u64) ktime_us_delta(ktime_get(), kt); do_div(delta, (u32) test_repeat_count); t->data[index].time = delta; } t->stop = get_cycles(); up_read(&prepare_for_test_rwsem); test_report_one_done(); /* * Wait for the kthread_stop() call. */ while (!kthread_should_stop()) msleep(10); return 0; } static int init_test_configurtion(void) { /* * A maximum number of workers is defined as hard-coded * value and set to USHRT_MAX. We add such gap just in * case and for potential heavy stressing. */ nr_threads = clamp(nr_threads, 1, (int) USHRT_MAX); /* Allocate the space for test instances. */ tdriver = kvcalloc(nr_threads, sizeof(*tdriver), GFP_KERNEL); if (tdriver == NULL) return -1; if (test_repeat_count <= 0) test_repeat_count = 1; if (test_loop_count <= 0) test_loop_count = 1; return 0; } static void do_concurrent_test(void) { int i, ret; /* * Set some basic configurations plus sanity check. */ ret = init_test_configurtion(); if (ret < 0) return; /* * Put on hold all workers. */ down_write(&prepare_for_test_rwsem); for (i = 0; i < nr_threads; i++) { struct test_driver *t = &tdriver[i]; t->task = kthread_run(test_func, t, "vmalloc_test/%d", i); if (!IS_ERR(t->task)) /* Success. */ atomic_inc(&test_n_undone); else pr_err("Failed to start %d kthread\n", i); } /* * Now let the workers do their job. */ up_write(&prepare_for_test_rwsem); /* * Sleep quiet until all workers are done with 1 second * interval. Since the test can take a lot of time we * can run into a stack trace of the hung task. That is * why we go with completion_timeout and HZ value. */ do { ret = wait_for_completion_timeout(&test_all_done_comp, HZ); } while (!ret); for (i = 0; i < nr_threads; i++) { struct test_driver *t = &tdriver[i]; int j; if (!IS_ERR(t->task)) kthread_stop(t->task); for (j = 0; j < ARRAY_SIZE(test_case_array); j++) { if (!((run_test_mask & (1 << j)) >> j)) continue; pr_info( "Summary: %s passed: %d failed: %d repeat: %d loops: %d avg: %llu usec\n", test_case_array[j].test_name, t->data[j].test_passed, t->data[j].test_failed, test_repeat_count, test_loop_count, t->data[j].time); } pr_info("All test took worker%d=%lu cycles\n", i, t->stop - t->start); } kvfree(tdriver); } static int vmalloc_test_init(void) { do_concurrent_test(); return -EAGAIN; /* Fail will directly unload the module */ } static void vmalloc_test_exit(void) { } module_init(vmalloc_test_init) module_exit(vmalloc_test_exit) MODULE_LICENSE("GPL"); MODULE_AUTHOR("Uladzislau Rezki"); MODULE_DESCRIPTION("vmalloc test module");