// 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>
#define __param(type, name, init, msg) \
static type name = init; \
module_param(name, type, 0444); \
MODULE_PARM_DESC(name, msg) \
__param(bool, single_cpu_test, false,
"Use single first online CPU to run tests");
__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, 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"
/* Add a new test case description here. */
);
/*
* Depends on single_cpu_test parameter. If it is true, then
* use first online CPU to trigger a test on, otherwise go with
* all online CPUs.
*/
static cpumask_t cpus_run_test_mask = CPU_MASK_NONE;
/*
* 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_range(size, align,
VMALLOC_START, VMALLOC_END,
GFP_KERNEL | __GFP_ZERO,
PAGE_KERNEL,
0, 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_range(PAGE_SIZE, align,
VMALLOC_START, VMALLOC_END,
GFP_KERNEL | __GFP_ZERO,
PAGE_KERNEL,
0, 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_range(5 * PAGE_SIZE,
THREAD_ALIGN << 1,
VMALLOC_START, VMALLOC_END,
GFP_KERNEL | __GFP_ZERO,
PAGE_KERNEL,
0, 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(3 * 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_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 },
/* Add a new test case here. */
};
struct test_case_data {
int test_failed;
int test_passed;
u64 time;
};
/* Split it to get rid of: WARNING: line over 80 characters */
static struct test_case_data
per_cpu_test_data[NR_CPUS][ARRAY_SIZE(test_case_array)];
static struct test_driver {
struct task_struct *task;
unsigned long start;
unsigned long stop;
int cpu;
} per_cpu_test_driver[NR_CPUS];
static void shuffle_array(int *arr, int n)
{
unsigned int rnd;
int i, j, x;
for (i = n - 1; i > 0; i--) {
get_random_bytes(&rnd, sizeof(rnd));
/* Cut the range. */
j = rnd % i;
/* Swap indexes. */
x = arr[i];
arr[i] = arr[j];
arr[j] = x;
}
}
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;
if (set_cpus_allowed_ptr(current, cpumask_of(t->cpu)) < 0)
pr_err("Failed to set affinity to %d CPU\n", t->cpu);
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())
per_cpu_test_data[t->cpu][index].test_passed++;
else
per_cpu_test_data[t->cpu][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);
per_cpu_test_data[t->cpu][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 void
init_test_configurtion(void)
{
/*
* Reset all data of all CPUs.
*/
memset(per_cpu_test_data, 0, sizeof(per_cpu_test_data));
if (single_cpu_test)
cpumask_set_cpu(cpumask_first(cpu_online_mask),
&cpus_run_test_mask);
else
cpumask_and(&cpus_run_test_mask, cpu_online_mask,
cpu_online_mask);
if (test_repeat_count <= 0)
test_repeat_count = 1;
if (test_loop_count <= 0)
test_loop_count = 1;
}
static void do_concurrent_test(void)
{
int cpu, ret;
/*
* Set some basic configurations plus sanity check.
*/
init_test_configurtion();
/*
* Put on hold all workers.
*/
down_write(&prepare_for_test_rwsem);
for_each_cpu(cpu, &cpus_run_test_mask) {
struct test_driver *t = &per_cpu_test_driver[cpu];
t->cpu = cpu;
t->task = kthread_run(test_func, t, "vmalloc_test/%d", cpu);
if (!IS_ERR(t->task))
/* Success. */
atomic_inc(&test_n_undone);
else
pr_err("Failed to start kthread for %d CPU\n", cpu);
}
/*
* 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_each_cpu(cpu, &cpus_run_test_mask) {
struct test_driver *t = &per_cpu_test_driver[cpu];
int i;
if (!IS_ERR(t->task))
kthread_stop(t->task);
for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
if (!((run_test_mask & (1 << i)) >> i))
continue;
pr_info(
"Summary: %s passed: %d failed: %d repeat: %d loops: %d avg: %llu usec\n",
test_case_array[i].test_name,
per_cpu_test_data[cpu][i].test_passed,
per_cpu_test_data[cpu][i].test_failed,
test_repeat_count, test_loop_count,
per_cpu_test_data[cpu][i].time);
}
pr_info("All test took CPU%d=%lu cycles\n",
cpu, t->stop - t->start);
}
}
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");
