linux/mm/damon/core-test.h
SeongJae Park 5e06ad5900 mm/damon/core-test: test max_nr_accesses overflow caused divide-by-zero
Commit 35f5d94187 ("mm/damon: implement a function for max nr_accesses
safe calculation") has fixed an overflow bug that could cause
divide-by-zero.  Add a kunit test for the bug to ensure similar bugs are
not introduced again.

Link: https://lkml.kernel.org/r/20231213190338.54146-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-20 14:48:13 -08:00

519 lines
14 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Data Access Monitor Unit Tests
*
* Copyright 2019 Amazon.com, Inc. or its affiliates. All rights reserved.
*
* Author: SeongJae Park <sj@kernel.org>
*/
#ifdef CONFIG_DAMON_KUNIT_TEST
#ifndef _DAMON_CORE_TEST_H
#define _DAMON_CORE_TEST_H
#include <kunit/test.h>
static void damon_test_regions(struct kunit *test)
{
struct damon_region *r;
struct damon_target *t;
r = damon_new_region(1, 2);
KUNIT_EXPECT_EQ(test, 1ul, r->ar.start);
KUNIT_EXPECT_EQ(test, 2ul, r->ar.end);
KUNIT_EXPECT_EQ(test, 0u, r->nr_accesses);
t = damon_new_target();
KUNIT_EXPECT_EQ(test, 0u, damon_nr_regions(t));
damon_add_region(r, t);
KUNIT_EXPECT_EQ(test, 1u, damon_nr_regions(t));
damon_destroy_region(r, t);
KUNIT_EXPECT_EQ(test, 0u, damon_nr_regions(t));
damon_free_target(t);
}
static unsigned int nr_damon_targets(struct damon_ctx *ctx)
{
struct damon_target *t;
unsigned int nr_targets = 0;
damon_for_each_target(t, ctx)
nr_targets++;
return nr_targets;
}
static void damon_test_target(struct kunit *test)
{
struct damon_ctx *c = damon_new_ctx();
struct damon_target *t;
t = damon_new_target();
KUNIT_EXPECT_EQ(test, 0u, nr_damon_targets(c));
damon_add_target(c, t);
KUNIT_EXPECT_EQ(test, 1u, nr_damon_targets(c));
damon_destroy_target(t);
KUNIT_EXPECT_EQ(test, 0u, nr_damon_targets(c));
damon_destroy_ctx(c);
}
/*
* Test kdamond_reset_aggregated()
*
* DAMON checks access to each region and aggregates this information as the
* access frequency of each region. In detail, it increases '->nr_accesses' of
* regions that an access has confirmed. 'kdamond_reset_aggregated()' flushes
* the aggregated information ('->nr_accesses' of each regions) to the result
* buffer. As a result of the flushing, the '->nr_accesses' of regions are
* initialized to zero.
*/
static void damon_test_aggregate(struct kunit *test)
{
struct damon_ctx *ctx = damon_new_ctx();
unsigned long saddr[][3] = {{10, 20, 30}, {5, 42, 49}, {13, 33, 55} };
unsigned long eaddr[][3] = {{15, 27, 40}, {31, 45, 55}, {23, 44, 66} };
unsigned long accesses[][3] = {{42, 95, 84}, {10, 20, 30}, {0, 1, 2} };
struct damon_target *t;
struct damon_region *r;
int it, ir;
for (it = 0; it < 3; it++) {
t = damon_new_target();
damon_add_target(ctx, t);
}
it = 0;
damon_for_each_target(t, ctx) {
for (ir = 0; ir < 3; ir++) {
r = damon_new_region(saddr[it][ir], eaddr[it][ir]);
r->nr_accesses = accesses[it][ir];
r->nr_accesses_bp = accesses[it][ir] * 10000;
damon_add_region(r, t);
}
it++;
}
kdamond_reset_aggregated(ctx);
it = 0;
damon_for_each_target(t, ctx) {
ir = 0;
/* '->nr_accesses' should be zeroed */
damon_for_each_region(r, t) {
KUNIT_EXPECT_EQ(test, 0u, r->nr_accesses);
ir++;
}
/* regions should be preserved */
KUNIT_EXPECT_EQ(test, 3, ir);
it++;
}
/* targets also should be preserved */
KUNIT_EXPECT_EQ(test, 3, it);
damon_destroy_ctx(ctx);
}
static void damon_test_split_at(struct kunit *test)
{
struct damon_ctx *c = damon_new_ctx();
struct damon_target *t;
struct damon_region *r, *r_new;
t = damon_new_target();
r = damon_new_region(0, 100);
r->nr_accesses_bp = 420000;
r->nr_accesses = 42;
r->last_nr_accesses = 15;
damon_add_region(r, t);
damon_split_region_at(t, r, 25);
KUNIT_EXPECT_EQ(test, r->ar.start, 0ul);
KUNIT_EXPECT_EQ(test, r->ar.end, 25ul);
r_new = damon_next_region(r);
KUNIT_EXPECT_EQ(test, r_new->ar.start, 25ul);
KUNIT_EXPECT_EQ(test, r_new->ar.end, 100ul);
KUNIT_EXPECT_EQ(test, r->nr_accesses_bp, r_new->nr_accesses_bp);
KUNIT_EXPECT_EQ(test, r->nr_accesses, r_new->nr_accesses);
KUNIT_EXPECT_EQ(test, r->last_nr_accesses, r_new->last_nr_accesses);
damon_free_target(t);
damon_destroy_ctx(c);
}
static void damon_test_merge_two(struct kunit *test)
{
struct damon_target *t;
struct damon_region *r, *r2, *r3;
int i;
t = damon_new_target();
r = damon_new_region(0, 100);
r->nr_accesses = 10;
r->nr_accesses_bp = 100000;
damon_add_region(r, t);
r2 = damon_new_region(100, 300);
r2->nr_accesses = 20;
r2->nr_accesses_bp = 200000;
damon_add_region(r2, t);
damon_merge_two_regions(t, r, r2);
KUNIT_EXPECT_EQ(test, r->ar.start, 0ul);
KUNIT_EXPECT_EQ(test, r->ar.end, 300ul);
KUNIT_EXPECT_EQ(test, r->nr_accesses, 16u);
i = 0;
damon_for_each_region(r3, t) {
KUNIT_EXPECT_PTR_EQ(test, r, r3);
i++;
}
KUNIT_EXPECT_EQ(test, i, 1);
damon_free_target(t);
}
static struct damon_region *__nth_region_of(struct damon_target *t, int idx)
{
struct damon_region *r;
unsigned int i = 0;
damon_for_each_region(r, t) {
if (i++ == idx)
return r;
}
return NULL;
}
static void damon_test_merge_regions_of(struct kunit *test)
{
struct damon_target *t;
struct damon_region *r;
unsigned long sa[] = {0, 100, 114, 122, 130, 156, 170, 184};
unsigned long ea[] = {100, 112, 122, 130, 156, 170, 184, 230};
unsigned int nrs[] = {0, 0, 10, 10, 20, 30, 1, 2};
unsigned long saddrs[] = {0, 114, 130, 156, 170};
unsigned long eaddrs[] = {112, 130, 156, 170, 230};
int i;
t = damon_new_target();
for (i = 0; i < ARRAY_SIZE(sa); i++) {
r = damon_new_region(sa[i], ea[i]);
r->nr_accesses = nrs[i];
r->nr_accesses_bp = nrs[i] * 10000;
damon_add_region(r, t);
}
damon_merge_regions_of(t, 9, 9999);
/* 0-112, 114-130, 130-156, 156-170 */
KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 5u);
for (i = 0; i < 5; i++) {
r = __nth_region_of(t, i);
KUNIT_EXPECT_EQ(test, r->ar.start, saddrs[i]);
KUNIT_EXPECT_EQ(test, r->ar.end, eaddrs[i]);
}
damon_free_target(t);
}
static void damon_test_split_regions_of(struct kunit *test)
{
struct damon_ctx *c = damon_new_ctx();
struct damon_target *t;
struct damon_region *r;
t = damon_new_target();
r = damon_new_region(0, 22);
damon_add_region(r, t);
damon_split_regions_of(t, 2);
KUNIT_EXPECT_LE(test, damon_nr_regions(t), 2u);
damon_free_target(t);
t = damon_new_target();
r = damon_new_region(0, 220);
damon_add_region(r, t);
damon_split_regions_of(t, 4);
KUNIT_EXPECT_LE(test, damon_nr_regions(t), 4u);
damon_free_target(t);
damon_destroy_ctx(c);
}
static void damon_test_ops_registration(struct kunit *test)
{
struct damon_ctx *c = damon_new_ctx();
struct damon_operations ops, bak;
/* DAMON_OPS_{V,P}ADDR are registered on subsys_initcall */
KUNIT_EXPECT_EQ(test, damon_select_ops(c, DAMON_OPS_VADDR), 0);
KUNIT_EXPECT_EQ(test, damon_select_ops(c, DAMON_OPS_PADDR), 0);
/* Double-registration is prohibited */
ops.id = DAMON_OPS_VADDR;
KUNIT_EXPECT_EQ(test, damon_register_ops(&ops), -EINVAL);
ops.id = DAMON_OPS_PADDR;
KUNIT_EXPECT_EQ(test, damon_register_ops(&ops), -EINVAL);
/* Unknown ops id cannot be registered */
KUNIT_EXPECT_EQ(test, damon_select_ops(c, NR_DAMON_OPS), -EINVAL);
/* Registration should success after unregistration */
mutex_lock(&damon_ops_lock);
bak = damon_registered_ops[DAMON_OPS_VADDR];
damon_registered_ops[DAMON_OPS_VADDR] = (struct damon_operations){};
mutex_unlock(&damon_ops_lock);
ops.id = DAMON_OPS_VADDR;
KUNIT_EXPECT_EQ(test, damon_register_ops(&ops), 0);
mutex_lock(&damon_ops_lock);
damon_registered_ops[DAMON_OPS_VADDR] = bak;
mutex_unlock(&damon_ops_lock);
/* Check double-registration failure again */
KUNIT_EXPECT_EQ(test, damon_register_ops(&ops), -EINVAL);
damon_destroy_ctx(c);
}
static void damon_test_set_regions(struct kunit *test)
{
struct damon_target *t = damon_new_target();
struct damon_region *r1 = damon_new_region(4, 16);
struct damon_region *r2 = damon_new_region(24, 32);
struct damon_addr_range range = {.start = 8, .end = 28};
unsigned long expects[] = {8, 16, 16, 24, 24, 28};
int expect_idx = 0;
struct damon_region *r;
damon_add_region(r1, t);
damon_add_region(r2, t);
damon_set_regions(t, &range, 1);
KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 3);
damon_for_each_region(r, t) {
KUNIT_EXPECT_EQ(test, r->ar.start, expects[expect_idx++]);
KUNIT_EXPECT_EQ(test, r->ar.end, expects[expect_idx++]);
}
damon_destroy_target(t);
}
static void damon_test_nr_accesses_to_accesses_bp(struct kunit *test)
{
struct damon_attrs attrs = {
.sample_interval = 10,
.aggr_interval = ((unsigned long)UINT_MAX + 1) * 10
};
KUNIT_EXPECT_EQ(test, damon_nr_accesses_to_accesses_bp(123, &attrs), 0);
}
static void damon_test_update_monitoring_result(struct kunit *test)
{
struct damon_attrs old_attrs = {
.sample_interval = 10, .aggr_interval = 1000,};
struct damon_attrs new_attrs;
struct damon_region *r = damon_new_region(3, 7);
r->nr_accesses = 15;
r->nr_accesses_bp = 150000;
r->age = 20;
new_attrs = (struct damon_attrs){
.sample_interval = 100, .aggr_interval = 10000,};
damon_update_monitoring_result(r, &old_attrs, &new_attrs);
KUNIT_EXPECT_EQ(test, r->nr_accesses, 15);
KUNIT_EXPECT_EQ(test, r->age, 2);
new_attrs = (struct damon_attrs){
.sample_interval = 1, .aggr_interval = 1000};
damon_update_monitoring_result(r, &old_attrs, &new_attrs);
KUNIT_EXPECT_EQ(test, r->nr_accesses, 150);
KUNIT_EXPECT_EQ(test, r->age, 2);
new_attrs = (struct damon_attrs){
.sample_interval = 1, .aggr_interval = 100};
damon_update_monitoring_result(r, &old_attrs, &new_attrs);
KUNIT_EXPECT_EQ(test, r->nr_accesses, 150);
KUNIT_EXPECT_EQ(test, r->age, 20);
damon_free_region(r);
}
static void damon_test_set_attrs(struct kunit *test)
{
struct damon_ctx *c = damon_new_ctx();
struct damon_attrs valid_attrs = {
.min_nr_regions = 10, .max_nr_regions = 1000,
.sample_interval = 5000, .aggr_interval = 100000,};
struct damon_attrs invalid_attrs;
KUNIT_EXPECT_EQ(test, damon_set_attrs(c, &valid_attrs), 0);
invalid_attrs = valid_attrs;
invalid_attrs.min_nr_regions = 1;
KUNIT_EXPECT_EQ(test, damon_set_attrs(c, &invalid_attrs), -EINVAL);
invalid_attrs = valid_attrs;
invalid_attrs.max_nr_regions = 9;
KUNIT_EXPECT_EQ(test, damon_set_attrs(c, &invalid_attrs), -EINVAL);
invalid_attrs = valid_attrs;
invalid_attrs.aggr_interval = 4999;
KUNIT_EXPECT_EQ(test, damon_set_attrs(c, &invalid_attrs), -EINVAL);
damon_destroy_ctx(c);
}
static void damon_test_moving_sum(struct kunit *test)
{
unsigned int mvsum = 50000, nomvsum = 50000, len_window = 10;
unsigned int new_values[] = {10000, 0, 10000, 0, 0, 0, 10000, 0, 0, 0};
unsigned int expects[] = {55000, 50000, 55000, 50000, 45000, 40000,
45000, 40000, 35000, 30000};
int i;
for (i = 0; i < ARRAY_SIZE(new_values); i++) {
mvsum = damon_moving_sum(mvsum, nomvsum, len_window,
new_values[i]);
KUNIT_EXPECT_EQ(test, mvsum, expects[i]);
}
}
static void damos_test_new_filter(struct kunit *test)
{
struct damos_filter *filter;
filter = damos_new_filter(DAMOS_FILTER_TYPE_ANON, true);
KUNIT_EXPECT_EQ(test, filter->type, DAMOS_FILTER_TYPE_ANON);
KUNIT_EXPECT_EQ(test, filter->matching, true);
KUNIT_EXPECT_PTR_EQ(test, filter->list.prev, &filter->list);
KUNIT_EXPECT_PTR_EQ(test, filter->list.next, &filter->list);
damos_destroy_filter(filter);
}
static void damos_test_filter_out(struct kunit *test)
{
struct damon_target *t;
struct damon_region *r, *r2;
struct damos_filter *f;
f = damos_new_filter(DAMOS_FILTER_TYPE_ADDR, true);
f->addr_range = (struct damon_addr_range){
.start = DAMON_MIN_REGION * 2, .end = DAMON_MIN_REGION * 6};
t = damon_new_target();
r = damon_new_region(DAMON_MIN_REGION * 3, DAMON_MIN_REGION * 5);
damon_add_region(r, t);
/* region in the range */
KUNIT_EXPECT_TRUE(test, __damos_filter_out(NULL, t, r, f));
KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 1);
/* region before the range */
r->ar.start = DAMON_MIN_REGION * 1;
r->ar.end = DAMON_MIN_REGION * 2;
KUNIT_EXPECT_FALSE(test, __damos_filter_out(NULL, t, r, f));
KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 1);
/* region after the range */
r->ar.start = DAMON_MIN_REGION * 6;
r->ar.end = DAMON_MIN_REGION * 8;
KUNIT_EXPECT_FALSE(test, __damos_filter_out(NULL, t, r, f));
KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 1);
/* region started before the range */
r->ar.start = DAMON_MIN_REGION * 1;
r->ar.end = DAMON_MIN_REGION * 4;
KUNIT_EXPECT_FALSE(test, __damos_filter_out(NULL, t, r, f));
/* filter should have split the region */
KUNIT_EXPECT_EQ(test, r->ar.start, DAMON_MIN_REGION * 1);
KUNIT_EXPECT_EQ(test, r->ar.end, DAMON_MIN_REGION * 2);
KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 2);
r2 = damon_next_region(r);
KUNIT_EXPECT_EQ(test, r2->ar.start, DAMON_MIN_REGION * 2);
KUNIT_EXPECT_EQ(test, r2->ar.end, DAMON_MIN_REGION * 4);
damon_destroy_region(r2, t);
/* region started in the range */
r->ar.start = DAMON_MIN_REGION * 2;
r->ar.end = DAMON_MIN_REGION * 8;
KUNIT_EXPECT_TRUE(test, __damos_filter_out(NULL, t, r, f));
/* filter should have split the region */
KUNIT_EXPECT_EQ(test, r->ar.start, DAMON_MIN_REGION * 2);
KUNIT_EXPECT_EQ(test, r->ar.end, DAMON_MIN_REGION * 6);
KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 2);
r2 = damon_next_region(r);
KUNIT_EXPECT_EQ(test, r2->ar.start, DAMON_MIN_REGION * 6);
KUNIT_EXPECT_EQ(test, r2->ar.end, DAMON_MIN_REGION * 8);
damon_destroy_region(r2, t);
damon_free_target(t);
damos_free_filter(f);
}
static void damon_test_feed_loop_next_input(struct kunit *test)
{
unsigned long last_input = 900000, current_score = 200;
/*
* If current score is lower than the goal, which is always 10,000
* (read the comment on damon_feed_loop_next_input()'s comment), next
* input should be higher than the last input.
*/
KUNIT_EXPECT_GT(test,
damon_feed_loop_next_input(last_input, current_score),
last_input);
/*
* If current score is higher than the goal, next input should be lower
* than the last input.
*/
current_score = 250000000;
KUNIT_EXPECT_LT(test,
damon_feed_loop_next_input(last_input, current_score),
last_input);
/*
* The next input depends on the distance between the current score and
* the goal
*/
KUNIT_EXPECT_GT(test,
damon_feed_loop_next_input(last_input, 200),
damon_feed_loop_next_input(last_input, 2000));
}
static struct kunit_case damon_test_cases[] = {
KUNIT_CASE(damon_test_target),
KUNIT_CASE(damon_test_regions),
KUNIT_CASE(damon_test_aggregate),
KUNIT_CASE(damon_test_split_at),
KUNIT_CASE(damon_test_merge_two),
KUNIT_CASE(damon_test_merge_regions_of),
KUNIT_CASE(damon_test_split_regions_of),
KUNIT_CASE(damon_test_ops_registration),
KUNIT_CASE(damon_test_set_regions),
KUNIT_CASE(damon_test_nr_accesses_to_accesses_bp),
KUNIT_CASE(damon_test_update_monitoring_result),
KUNIT_CASE(damon_test_set_attrs),
KUNIT_CASE(damon_test_moving_sum),
KUNIT_CASE(damos_test_new_filter),
KUNIT_CASE(damos_test_filter_out),
KUNIT_CASE(damon_test_feed_loop_next_input),
{},
};
static struct kunit_suite damon_test_suite = {
.name = "damon",
.test_cases = damon_test_cases,
};
kunit_test_suite(damon_test_suite);
#endif /* _DAMON_CORE_TEST_H */
#endif /* CONFIG_DAMON_KUNIT_TEST */