linux/lib/test_xarray.c
Matthew Wilcox b803b42823 xarray: Add XArray iterators
The xa_for_each iterator allows the user to efficiently walk a range
of the array, executing the loop body once for each entry in that
range that matches the filter.  This commit also includes xa_find()
and xa_find_after() which are helper functions for xa_for_each() but
may also be useful in their own right.

In the xas family of functions, we have xas_for_each(), xas_find(),
xas_next_entry(), xas_for_each_tagged(), xas_find_tagged(),
xas_next_tagged() and xas_pause().

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:45:58 -04:00

494 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* test_xarray.c: Test the XArray API
* Copyright (c) 2017-2018 Microsoft Corporation
* Author: Matthew Wilcox <willy@infradead.org>
*/
#include <linux/xarray.h>
#include <linux/module.h>
static unsigned int tests_run;
static unsigned int tests_passed;
#ifndef XA_DEBUG
# ifdef __KERNEL__
void xa_dump(const struct xarray *xa) { }
# endif
#undef XA_BUG_ON
#define XA_BUG_ON(xa, x) do { \
tests_run++; \
if (x) { \
printk("BUG at %s:%d\n", __func__, __LINE__); \
xa_dump(xa); \
dump_stack(); \
} else { \
tests_passed++; \
} \
} while (0)
#endif
static void *xa_store_index(struct xarray *xa, unsigned long index, gfp_t gfp)
{
return xa_store(xa, index, xa_mk_value(index & LONG_MAX), gfp);
}
static void xa_erase_index(struct xarray *xa, unsigned long index)
{
XA_BUG_ON(xa, xa_erase(xa, index) != xa_mk_value(index & LONG_MAX));
XA_BUG_ON(xa, xa_load(xa, index) != NULL);
}
/*
* If anyone needs this, please move it to xarray.c. We have no current
* users outside the test suite because all current multislot users want
* to use the advanced API.
*/
static void *xa_store_order(struct xarray *xa, unsigned long index,
unsigned order, void *entry, gfp_t gfp)
{
XA_STATE_ORDER(xas, xa, index, order);
void *curr;
do {
xas_lock(&xas);
curr = xas_store(&xas, entry);
xas_unlock(&xas);
} while (xas_nomem(&xas, gfp));
return curr;
}
static noinline void check_xa_err(struct xarray *xa)
{
XA_BUG_ON(xa, xa_err(xa_store_index(xa, 0, GFP_NOWAIT)) != 0);
XA_BUG_ON(xa, xa_err(xa_erase(xa, 0)) != 0);
#ifndef __KERNEL__
/* The kernel does not fail GFP_NOWAIT allocations */
XA_BUG_ON(xa, xa_err(xa_store_index(xa, 1, GFP_NOWAIT)) != -ENOMEM);
XA_BUG_ON(xa, xa_err(xa_store_index(xa, 1, GFP_NOWAIT)) != -ENOMEM);
#endif
XA_BUG_ON(xa, xa_err(xa_store_index(xa, 1, GFP_KERNEL)) != 0);
XA_BUG_ON(xa, xa_err(xa_store(xa, 1, xa_mk_value(0), GFP_KERNEL)) != 0);
XA_BUG_ON(xa, xa_err(xa_erase(xa, 1)) != 0);
// kills the test-suite :-(
// XA_BUG_ON(xa, xa_err(xa_store(xa, 0, xa_mk_internal(0), 0)) != -EINVAL);
}
static noinline void check_xas_retry(struct xarray *xa)
{
XA_STATE(xas, xa, 0);
void *entry;
xa_store_index(xa, 0, GFP_KERNEL);
xa_store_index(xa, 1, GFP_KERNEL);
rcu_read_lock();
XA_BUG_ON(xa, xas_find(&xas, ULONG_MAX) != xa_mk_value(0));
xa_erase_index(xa, 1);
XA_BUG_ON(xa, !xa_is_retry(xas_reload(&xas)));
XA_BUG_ON(xa, xas_retry(&xas, NULL));
XA_BUG_ON(xa, xas_retry(&xas, xa_mk_value(0)));
xas_reset(&xas);
XA_BUG_ON(xa, xas.xa_node != XAS_RESTART);
XA_BUG_ON(xa, xas_next_entry(&xas, ULONG_MAX) != xa_mk_value(0));
XA_BUG_ON(xa, xas.xa_node != NULL);
XA_BUG_ON(xa, xa_store_index(xa, 1, GFP_KERNEL) != NULL);
XA_BUG_ON(xa, !xa_is_internal(xas_reload(&xas)));
xas.xa_node = XAS_RESTART;
XA_BUG_ON(xa, xas_next_entry(&xas, ULONG_MAX) != xa_mk_value(0));
rcu_read_unlock();
/* Make sure we can iterate through retry entries */
xas_lock(&xas);
xas_set(&xas, 0);
xas_store(&xas, XA_RETRY_ENTRY);
xas_set(&xas, 1);
xas_store(&xas, XA_RETRY_ENTRY);
xas_set(&xas, 0);
xas_for_each(&xas, entry, ULONG_MAX) {
xas_store(&xas, xa_mk_value(xas.xa_index));
}
xas_unlock(&xas);
xa_erase_index(xa, 0);
xa_erase_index(xa, 1);
}
static noinline void check_xa_load(struct xarray *xa)
{
unsigned long i, j;
for (i = 0; i < 1024; i++) {
for (j = 0; j < 1024; j++) {
void *entry = xa_load(xa, j);
if (j < i)
XA_BUG_ON(xa, xa_to_value(entry) != j);
else
XA_BUG_ON(xa, entry);
}
XA_BUG_ON(xa, xa_store_index(xa, i, GFP_KERNEL) != NULL);
}
for (i = 0; i < 1024; i++) {
for (j = 0; j < 1024; j++) {
void *entry = xa_load(xa, j);
if (j >= i)
XA_BUG_ON(xa, xa_to_value(entry) != j);
else
XA_BUG_ON(xa, entry);
}
xa_erase_index(xa, i);
}
XA_BUG_ON(xa, !xa_empty(xa));
}
static noinline void check_xa_mark_1(struct xarray *xa, unsigned long index)
{
unsigned int order;
unsigned int max_order = IS_ENABLED(CONFIG_XARRAY_MULTI) ? 8 : 1;
/* NULL elements have no marks set */
XA_BUG_ON(xa, xa_get_mark(xa, index, XA_MARK_0));
xa_set_mark(xa, index, XA_MARK_0);
XA_BUG_ON(xa, xa_get_mark(xa, index, XA_MARK_0));
/* Storing a pointer will not make a mark appear */
XA_BUG_ON(xa, xa_store_index(xa, index, GFP_KERNEL) != NULL);
XA_BUG_ON(xa, xa_get_mark(xa, index, XA_MARK_0));
xa_set_mark(xa, index, XA_MARK_0);
XA_BUG_ON(xa, !xa_get_mark(xa, index, XA_MARK_0));
/* Setting one mark will not set another mark */
XA_BUG_ON(xa, xa_get_mark(xa, index + 1, XA_MARK_0));
XA_BUG_ON(xa, xa_get_mark(xa, index, XA_MARK_1));
/* Storing NULL clears marks, and they can't be set again */
xa_erase_index(xa, index);
XA_BUG_ON(xa, !xa_empty(xa));
XA_BUG_ON(xa, xa_get_mark(xa, index, XA_MARK_0));
xa_set_mark(xa, index, XA_MARK_0);
XA_BUG_ON(xa, xa_get_mark(xa, index, XA_MARK_0));
/*
* Storing a multi-index entry over entries with marks gives the
* entire entry the union of the marks
*/
BUG_ON((index % 4) != 0);
for (order = 2; order < max_order; order++) {
unsigned long base = round_down(index, 1UL << order);
unsigned long next = base + (1UL << order);
unsigned long i;
XA_BUG_ON(xa, xa_store_index(xa, index + 1, GFP_KERNEL));
xa_set_mark(xa, index + 1, XA_MARK_0);
XA_BUG_ON(xa, xa_store_index(xa, index + 2, GFP_KERNEL));
xa_set_mark(xa, index + 2, XA_MARK_1);
XA_BUG_ON(xa, xa_store_index(xa, next, GFP_KERNEL));
xa_store_order(xa, index, order, xa_mk_value(index),
GFP_KERNEL);
for (i = base; i < next; i++) {
XA_BUG_ON(xa, !xa_get_mark(xa, i, XA_MARK_0));
XA_BUG_ON(xa, !xa_get_mark(xa, i, XA_MARK_1));
XA_BUG_ON(xa, xa_get_mark(xa, i, XA_MARK_2));
}
XA_BUG_ON(xa, xa_get_mark(xa, next, XA_MARK_0));
XA_BUG_ON(xa, xa_get_mark(xa, next, XA_MARK_1));
XA_BUG_ON(xa, xa_get_mark(xa, next, XA_MARK_2));
xa_erase_index(xa, index);
xa_erase_index(xa, next);
XA_BUG_ON(xa, !xa_empty(xa));
}
XA_BUG_ON(xa, !xa_empty(xa));
}
static noinline void check_xa_mark(struct xarray *xa)
{
unsigned long index;
for (index = 0; index < 16384; index += 4)
check_xa_mark_1(xa, index);
}
static noinline void check_xa_shrink(struct xarray *xa)
{
XA_STATE(xas, xa, 1);
struct xa_node *node;
XA_BUG_ON(xa, !xa_empty(xa));
XA_BUG_ON(xa, xa_store_index(xa, 0, GFP_KERNEL) != NULL);
XA_BUG_ON(xa, xa_store_index(xa, 1, GFP_KERNEL) != NULL);
/*
* Check that erasing the entry at 1 shrinks the tree and properly
* marks the node as being deleted.
*/
xas_lock(&xas);
XA_BUG_ON(xa, xas_load(&xas) != xa_mk_value(1));
node = xas.xa_node;
XA_BUG_ON(xa, xa_entry_locked(xa, node, 0) != xa_mk_value(0));
XA_BUG_ON(xa, xas_store(&xas, NULL) != xa_mk_value(1));
XA_BUG_ON(xa, xa_load(xa, 1) != NULL);
XA_BUG_ON(xa, xas.xa_node != XAS_BOUNDS);
XA_BUG_ON(xa, xa_entry_locked(xa, node, 0) != XA_RETRY_ENTRY);
XA_BUG_ON(xa, xas_load(&xas) != NULL);
xas_unlock(&xas);
XA_BUG_ON(xa, xa_load(xa, 0) != xa_mk_value(0));
xa_erase_index(xa, 0);
XA_BUG_ON(xa, !xa_empty(xa));
}
static noinline void check_cmpxchg(struct xarray *xa)
{
void *FIVE = xa_mk_value(5);
void *SIX = xa_mk_value(6);
void *LOTS = xa_mk_value(12345678);
XA_BUG_ON(xa, !xa_empty(xa));
XA_BUG_ON(xa, xa_store_index(xa, 12345678, GFP_KERNEL) != NULL);
XA_BUG_ON(xa, xa_insert(xa, 12345678, xa, GFP_KERNEL) != -EEXIST);
XA_BUG_ON(xa, xa_cmpxchg(xa, 12345678, SIX, FIVE, GFP_KERNEL) != LOTS);
XA_BUG_ON(xa, xa_cmpxchg(xa, 12345678, LOTS, FIVE, GFP_KERNEL) != LOTS);
XA_BUG_ON(xa, xa_cmpxchg(xa, 12345678, FIVE, LOTS, GFP_KERNEL) != FIVE);
XA_BUG_ON(xa, xa_cmpxchg(xa, 5, FIVE, NULL, GFP_KERNEL) != NULL);
XA_BUG_ON(xa, xa_cmpxchg(xa, 5, NULL, FIVE, GFP_KERNEL) != NULL);
xa_erase_index(xa, 12345678);
xa_erase_index(xa, 5);
XA_BUG_ON(xa, !xa_empty(xa));
}
static noinline void check_xas_erase(struct xarray *xa)
{
XA_STATE(xas, xa, 0);
void *entry;
unsigned long i, j;
for (i = 0; i < 200; i++) {
for (j = i; j < 2 * i + 17; j++) {
xas_set(&xas, j);
do {
xas_lock(&xas);
xas_store(&xas, xa_mk_value(j));
xas_unlock(&xas);
} while (xas_nomem(&xas, GFP_KERNEL));
}
xas_set(&xas, ULONG_MAX);
do {
xas_lock(&xas);
xas_store(&xas, xa_mk_value(0));
xas_unlock(&xas);
} while (xas_nomem(&xas, GFP_KERNEL));
xas_lock(&xas);
xas_store(&xas, NULL);
xas_set(&xas, 0);
j = i;
xas_for_each(&xas, entry, ULONG_MAX) {
XA_BUG_ON(xa, entry != xa_mk_value(j));
xas_store(&xas, NULL);
j++;
}
xas_unlock(&xas);
XA_BUG_ON(xa, !xa_empty(xa));
}
}
static noinline void check_multi_store(struct xarray *xa)
{
#ifdef CONFIG_XARRAY_MULTI
unsigned long i, j, k;
unsigned int max_order = (sizeof(long) == 4) ? 30 : 60;
/* Loading from any position returns the same value */
xa_store_order(xa, 0, 1, xa_mk_value(0), GFP_KERNEL);
XA_BUG_ON(xa, xa_load(xa, 0) != xa_mk_value(0));
XA_BUG_ON(xa, xa_load(xa, 1) != xa_mk_value(0));
XA_BUG_ON(xa, xa_load(xa, 2) != NULL);
rcu_read_lock();
XA_BUG_ON(xa, xa_to_node(xa_head(xa))->count != 2);
XA_BUG_ON(xa, xa_to_node(xa_head(xa))->nr_values != 2);
rcu_read_unlock();
/* Storing adjacent to the value does not alter the value */
xa_store(xa, 3, xa, GFP_KERNEL);
XA_BUG_ON(xa, xa_load(xa, 0) != xa_mk_value(0));
XA_BUG_ON(xa, xa_load(xa, 1) != xa_mk_value(0));
XA_BUG_ON(xa, xa_load(xa, 2) != NULL);
rcu_read_lock();
XA_BUG_ON(xa, xa_to_node(xa_head(xa))->count != 3);
XA_BUG_ON(xa, xa_to_node(xa_head(xa))->nr_values != 2);
rcu_read_unlock();
/* Overwriting multiple indexes works */
xa_store_order(xa, 0, 2, xa_mk_value(1), GFP_KERNEL);
XA_BUG_ON(xa, xa_load(xa, 0) != xa_mk_value(1));
XA_BUG_ON(xa, xa_load(xa, 1) != xa_mk_value(1));
XA_BUG_ON(xa, xa_load(xa, 2) != xa_mk_value(1));
XA_BUG_ON(xa, xa_load(xa, 3) != xa_mk_value(1));
XA_BUG_ON(xa, xa_load(xa, 4) != NULL);
rcu_read_lock();
XA_BUG_ON(xa, xa_to_node(xa_head(xa))->count != 4);
XA_BUG_ON(xa, xa_to_node(xa_head(xa))->nr_values != 4);
rcu_read_unlock();
/* We can erase multiple values with a single store */
xa_store_order(xa, 0, 63, NULL, GFP_KERNEL);
XA_BUG_ON(xa, !xa_empty(xa));
/* Even when the first slot is empty but the others aren't */
xa_store_index(xa, 1, GFP_KERNEL);
xa_store_index(xa, 2, GFP_KERNEL);
xa_store_order(xa, 0, 2, NULL, GFP_KERNEL);
XA_BUG_ON(xa, !xa_empty(xa));
for (i = 0; i < max_order; i++) {
for (j = 0; j < max_order; j++) {
xa_store_order(xa, 0, i, xa_mk_value(i), GFP_KERNEL);
xa_store_order(xa, 0, j, xa_mk_value(j), GFP_KERNEL);
for (k = 0; k < max_order; k++) {
void *entry = xa_load(xa, (1UL << k) - 1);
if ((i < k) && (j < k))
XA_BUG_ON(xa, entry != NULL);
else
XA_BUG_ON(xa, entry != xa_mk_value(j));
}
xa_erase(xa, 0);
XA_BUG_ON(xa, !xa_empty(xa));
}
}
#endif
}
static noinline void check_multi_find(struct xarray *xa)
{
#ifdef CONFIG_XARRAY_MULTI
unsigned long index;
xa_store_order(xa, 12, 2, xa_mk_value(12), GFP_KERNEL);
XA_BUG_ON(xa, xa_store_index(xa, 16, GFP_KERNEL) != NULL);
index = 0;
XA_BUG_ON(xa, xa_find(xa, &index, ULONG_MAX, XA_PRESENT) !=
xa_mk_value(12));
XA_BUG_ON(xa, index != 12);
index = 13;
XA_BUG_ON(xa, xa_find(xa, &index, ULONG_MAX, XA_PRESENT) !=
xa_mk_value(12));
XA_BUG_ON(xa, (index < 12) || (index >= 16));
XA_BUG_ON(xa, xa_find_after(xa, &index, ULONG_MAX, XA_PRESENT) !=
xa_mk_value(16));
XA_BUG_ON(xa, index != 16);
xa_erase_index(xa, 12);
xa_erase_index(xa, 16);
XA_BUG_ON(xa, !xa_empty(xa));
#endif
}
static noinline void check_multi_find_2(struct xarray *xa)
{
unsigned int max_order = IS_ENABLED(CONFIG_XARRAY_MULTI) ? 10 : 1;
unsigned int i, j;
void *entry;
for (i = 0; i < max_order; i++) {
unsigned long index = 1UL << i;
for (j = 0; j < index; j++) {
XA_STATE(xas, xa, j + index);
xa_store_index(xa, index - 1, GFP_KERNEL);
xa_store_order(xa, index, i, xa_mk_value(index),
GFP_KERNEL);
rcu_read_lock();
xas_for_each(&xas, entry, ULONG_MAX) {
xa_erase_index(xa, index);
}
rcu_read_unlock();
xa_erase_index(xa, index - 1);
XA_BUG_ON(xa, !xa_empty(xa));
}
}
}
static noinline void check_find(struct xarray *xa)
{
unsigned long i, j, k;
XA_BUG_ON(xa, !xa_empty(xa));
/*
* Check xa_find with all pairs between 0 and 99 inclusive,
* starting at every index between 0 and 99
*/
for (i = 0; i < 100; i++) {
XA_BUG_ON(xa, xa_store_index(xa, i, GFP_KERNEL) != NULL);
xa_set_mark(xa, i, XA_MARK_0);
for (j = 0; j < i; j++) {
XA_BUG_ON(xa, xa_store_index(xa, j, GFP_KERNEL) !=
NULL);
xa_set_mark(xa, j, XA_MARK_0);
for (k = 0; k < 100; k++) {
unsigned long index = k;
void *entry = xa_find(xa, &index, ULONG_MAX,
XA_PRESENT);
if (k <= j)
XA_BUG_ON(xa, index != j);
else if (k <= i)
XA_BUG_ON(xa, index != i);
else
XA_BUG_ON(xa, entry != NULL);
index = k;
entry = xa_find(xa, &index, ULONG_MAX,
XA_MARK_0);
if (k <= j)
XA_BUG_ON(xa, index != j);
else if (k <= i)
XA_BUG_ON(xa, index != i);
else
XA_BUG_ON(xa, entry != NULL);
}
xa_erase_index(xa, j);
XA_BUG_ON(xa, xa_get_mark(xa, j, XA_MARK_0));
XA_BUG_ON(xa, !xa_get_mark(xa, i, XA_MARK_0));
}
xa_erase_index(xa, i);
XA_BUG_ON(xa, xa_get_mark(xa, i, XA_MARK_0));
}
XA_BUG_ON(xa, !xa_empty(xa));
check_multi_find(xa);
check_multi_find_2(xa);
}
static DEFINE_XARRAY(array);
static int xarray_checks(void)
{
check_xa_err(&array);
check_xas_retry(&array);
check_xa_load(&array);
check_xa_mark(&array);
check_xa_shrink(&array);
check_xas_erase(&array);
check_cmpxchg(&array);
check_multi_store(&array);
check_find(&array);
printk("XArray: %u of %u tests passed\n", tests_passed, tests_run);
return (tests_run == tests_passed) ? 0 : -EINVAL;
}
static void xarray_exit(void)
{
}
module_init(xarray_checks);
module_exit(xarray_exit);
MODULE_AUTHOR("Matthew Wilcox <willy@infradead.org>");
MODULE_LICENSE("GPL");