lib: Introduce priority array area manager
This introduces a infrastructure for management of linear priority
areas. Priority order in an array matters, however order of items inside
a priority group does not matter.
As an initial implementation, L-sort algorithm is used. It is quite
trivial. More advanced algorithm called P-sort will be introduced as a
follow-up. The infrastructure is prepared for other algos.
Alongside this, a testing module is introduced as well.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/lib/test_parman.c b/lib/test_parman.c
new file mode 100644
index 0000000..fe9f3a7
--- /dev/null
+++ b/lib/test_parman.c
@@ -0,0 +1,395 @@
+/*
+ * lib/test_parman.c - Test module for parman
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Jiri Pirko <jiri@mellanox.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/random.h>
+#include <linux/parman.h>
+
+#define TEST_PARMAN_PRIO_SHIFT 7 /* defines number of prios for testing */
+#define TEST_PARMAN_PRIO_COUNT BIT(TEST_PARMAN_PRIO_SHIFT)
+#define TEST_PARMAN_PRIO_MASK (TEST_PARMAN_PRIO_COUNT - 1)
+
+#define TEST_PARMAN_ITEM_SHIFT 13 /* defines a total number
+ * of items for testing
+ */
+#define TEST_PARMAN_ITEM_COUNT BIT(TEST_PARMAN_ITEM_SHIFT)
+#define TEST_PARMAN_ITEM_MASK (TEST_PARMAN_ITEM_COUNT - 1)
+
+#define TEST_PARMAN_BASE_SHIFT 8
+#define TEST_PARMAN_BASE_COUNT BIT(TEST_PARMAN_BASE_SHIFT)
+#define TEST_PARMAN_RESIZE_STEP_SHIFT 7
+#define TEST_PARMAN_RESIZE_STEP_COUNT BIT(TEST_PARMAN_RESIZE_STEP_SHIFT)
+
+#define TEST_PARMAN_BULK_MAX_SHIFT (2 + TEST_PARMAN_RESIZE_STEP_SHIFT)
+#define TEST_PARMAN_BULK_MAX_COUNT BIT(TEST_PARMAN_BULK_MAX_SHIFT)
+#define TEST_PARMAN_BULK_MAX_MASK (TEST_PARMAN_BULK_MAX_COUNT - 1)
+
+#define TEST_PARMAN_RUN_BUDGET (TEST_PARMAN_ITEM_COUNT * 256)
+
+struct test_parman_prio {
+ struct parman_prio parman_prio;
+ unsigned long priority;
+};
+
+struct test_parman_item {
+ struct parman_item parman_item;
+ struct test_parman_prio *prio;
+ bool used;
+};
+
+struct test_parman {
+ struct parman *parman;
+ struct test_parman_item **prio_array;
+ unsigned long prio_array_limit;
+ struct test_parman_prio prios[TEST_PARMAN_PRIO_COUNT];
+ struct test_parman_item items[TEST_PARMAN_ITEM_COUNT];
+ struct rnd_state rnd;
+ unsigned long run_budget;
+ unsigned long bulk_budget;
+ bool bulk_noop;
+ unsigned int used_items;
+};
+
+#define ITEM_PTRS_SIZE(count) (sizeof(struct test_parman_item *) * (count))
+
+static int test_parman_resize(void *priv, unsigned long new_count)
+{
+ struct test_parman *test_parman = priv;
+ struct test_parman_item **prio_array;
+ unsigned long old_count;
+
+ prio_array = krealloc(test_parman->prio_array,
+ ITEM_PTRS_SIZE(new_count), GFP_KERNEL);
+ if (new_count == 0)
+ return 0;
+ if (!prio_array)
+ return -ENOMEM;
+ old_count = test_parman->prio_array_limit;
+ if (new_count > old_count)
+ memset(&prio_array[old_count], 0,
+ ITEM_PTRS_SIZE(new_count - old_count));
+ test_parman->prio_array = prio_array;
+ test_parman->prio_array_limit = new_count;
+ return 0;
+}
+
+static void test_parman_move(void *priv, unsigned long from_index,
+ unsigned long to_index, unsigned long count)
+{
+ struct test_parman *test_parman = priv;
+ struct test_parman_item **prio_array = test_parman->prio_array;
+
+ memmove(&prio_array[to_index], &prio_array[from_index],
+ ITEM_PTRS_SIZE(count));
+ memset(&prio_array[from_index], 0, ITEM_PTRS_SIZE(count));
+}
+
+static const struct parman_ops test_parman_lsort_ops = {
+ .base_count = TEST_PARMAN_BASE_COUNT,
+ .resize_step = TEST_PARMAN_RESIZE_STEP_COUNT,
+ .resize = test_parman_resize,
+ .move = test_parman_move,
+ .algo = PARMAN_ALGO_TYPE_LSORT,
+};
+
+static void test_parman_rnd_init(struct test_parman *test_parman)
+{
+ prandom_seed_state(&test_parman->rnd, 3141592653589793238ULL);
+}
+
+static u32 test_parman_rnd_get(struct test_parman *test_parman)
+{
+ return prandom_u32_state(&test_parman->rnd);
+}
+
+static unsigned long test_parman_priority_gen(struct test_parman *test_parman)
+{
+ unsigned long priority;
+ int i;
+
+again:
+ priority = test_parman_rnd_get(test_parman);
+ if (priority == 0)
+ goto again;
+
+ for (i = 0; i < TEST_PARMAN_PRIO_COUNT; i++) {
+ struct test_parman_prio *prio = &test_parman->prios[i];
+
+ if (prio->priority == 0)
+ break;
+ if (prio->priority == priority)
+ goto again;
+ }
+ return priority;
+}
+
+static void test_parman_prios_init(struct test_parman *test_parman)
+{
+ int i;
+
+ for (i = 0; i < TEST_PARMAN_PRIO_COUNT; i++) {
+ struct test_parman_prio *prio = &test_parman->prios[i];
+
+ /* Assign random uniqueue priority to each prio structure */
+ prio->priority = test_parman_priority_gen(test_parman);
+ parman_prio_init(test_parman->parman, &prio->parman_prio,
+ prio->priority);
+ }
+}
+
+static void test_parman_prios_fini(struct test_parman *test_parman)
+{
+ int i;
+
+ for (i = 0; i < TEST_PARMAN_PRIO_COUNT; i++) {
+ struct test_parman_prio *prio = &test_parman->prios[i];
+
+ parman_prio_fini(&prio->parman_prio);
+ }
+}
+
+static void test_parman_items_init(struct test_parman *test_parman)
+{
+ int i;
+
+ for (i = 0; i < TEST_PARMAN_ITEM_COUNT; i++) {
+ struct test_parman_item *item = &test_parman->items[i];
+ unsigned int prio_index = test_parman_rnd_get(test_parman) &
+ TEST_PARMAN_PRIO_MASK;
+
+ /* Assign random prio to each item structure */
+ item->prio = &test_parman->prios[prio_index];
+ }
+}
+
+static void test_parman_items_fini(struct test_parman *test_parman)
+{
+ int i;
+
+ for (i = 0; i < TEST_PARMAN_ITEM_COUNT; i++) {
+ struct test_parman_item *item = &test_parman->items[i];
+
+ if (!item->used)
+ continue;
+ parman_item_remove(test_parman->parman,
+ &item->prio->parman_prio,
+ &item->parman_item);
+ }
+}
+
+static struct test_parman *test_parman_create(const struct parman_ops *ops)
+{
+ struct test_parman *test_parman;
+ int err;
+
+ test_parman = kzalloc(sizeof(*test_parman), GFP_KERNEL);
+ if (!test_parman)
+ return ERR_PTR(-ENOMEM);
+ err = test_parman_resize(test_parman, TEST_PARMAN_BASE_COUNT);
+ if (err)
+ goto err_resize;
+ test_parman->parman = parman_create(ops, test_parman);
+ if (!test_parman->parman) {
+ err = -ENOMEM;
+ goto err_parman_create;
+ }
+ test_parman_rnd_init(test_parman);
+ test_parman_prios_init(test_parman);
+ test_parman_items_init(test_parman);
+ test_parman->run_budget = TEST_PARMAN_RUN_BUDGET;
+ return test_parman;
+
+err_parman_create:
+ test_parman_resize(test_parman, 0);
+err_resize:
+ kfree(test_parman);
+ return ERR_PTR(err);
+}
+
+static void test_parman_destroy(struct test_parman *test_parman)
+{
+ test_parman_items_fini(test_parman);
+ test_parman_prios_fini(test_parman);
+ parman_destroy(test_parman->parman);
+ test_parman_resize(test_parman, 0);
+ kfree(test_parman);
+}
+
+static bool test_parman_run_check_budgets(struct test_parman *test_parman)
+{
+ if (test_parman->run_budget-- == 0)
+ return false;
+ if (test_parman->bulk_budget-- != 0)
+ return true;
+
+ test_parman->bulk_budget = test_parman_rnd_get(test_parman) &
+ TEST_PARMAN_BULK_MAX_MASK;
+ test_parman->bulk_noop = test_parman_rnd_get(test_parman) & 1;
+ return true;
+}
+
+static int test_parman_run(struct test_parman *test_parman)
+{
+ unsigned int i = test_parman_rnd_get(test_parman);
+ int err;
+
+ while (test_parman_run_check_budgets(test_parman)) {
+ unsigned int item_index = i++ & TEST_PARMAN_ITEM_MASK;
+ struct test_parman_item *item = &test_parman->items[item_index];
+
+ if (test_parman->bulk_noop)
+ continue;
+
+ if (!item->used) {
+ err = parman_item_add(test_parman->parman,
+ &item->prio->parman_prio,
+ &item->parman_item);
+ if (err)
+ return err;
+ test_parman->prio_array[item->parman_item.index] = item;
+ test_parman->used_items++;
+ } else {
+ test_parman->prio_array[item->parman_item.index] = NULL;
+ parman_item_remove(test_parman->parman,
+ &item->prio->parman_prio,
+ &item->parman_item);
+ test_parman->used_items--;
+ }
+ item->used = !item->used;
+ }
+ return 0;
+}
+
+static int test_parman_check_array(struct test_parman *test_parman,
+ bool gaps_allowed)
+{
+ unsigned int last_unused_items = 0;
+ unsigned long last_priority = 0;
+ unsigned int used_items = 0;
+ int i;
+
+ if (test_parman->prio_array_limit < TEST_PARMAN_BASE_COUNT) {
+ pr_err("Array limit is lower than the base count (%lu < %lu)\n",
+ test_parman->prio_array_limit, TEST_PARMAN_BASE_COUNT);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < test_parman->prio_array_limit; i++) {
+ struct test_parman_item *item = test_parman->prio_array[i];
+
+ if (!item) {
+ last_unused_items++;
+ continue;
+ }
+ if (last_unused_items && !gaps_allowed) {
+ pr_err("Gap found in array even though they are forbidden\n");
+ return -EINVAL;
+ }
+
+ last_unused_items = 0;
+ used_items++;
+
+ if (item->prio->priority < last_priority) {
+ pr_err("Item belongs under higher priority then the last one (current: %lu, previous: %lu)\n",
+ item->prio->priority, last_priority);
+ return -EINVAL;
+ }
+ last_priority = item->prio->priority;
+
+ if (item->parman_item.index != i) {
+ pr_err("Item has different index in compare to where it actualy is (%lu != %d)\n",
+ item->parman_item.index, i);
+ return -EINVAL;
+ }
+ }
+
+ if (used_items != test_parman->used_items) {
+ pr_err("Number of used items in array does not match (%u != %u)\n",
+ used_items, test_parman->used_items);
+ return -EINVAL;
+ }
+
+ if (last_unused_items >= TEST_PARMAN_RESIZE_STEP_COUNT) {
+ pr_err("Number of unused item at the end of array is bigger than resize step (%u >= %lu)\n",
+ last_unused_items, TEST_PARMAN_RESIZE_STEP_COUNT);
+ return -EINVAL;
+ }
+
+ pr_info("Priority array check successful\n");
+
+ return 0;
+}
+
+static int test_parman_lsort(void)
+{
+ struct test_parman *test_parman;
+ int err;
+
+ test_parman = test_parman_create(&test_parman_lsort_ops);
+ if (IS_ERR(test_parman))
+ return PTR_ERR(test_parman);
+
+ err = test_parman_run(test_parman);
+ if (err)
+ goto out;
+
+ err = test_parman_check_array(test_parman, false);
+ if (err)
+ goto out;
+out:
+ test_parman_destroy(test_parman);
+ return err;
+}
+
+static int __init test_parman_init(void)
+{
+ return test_parman_lsort();
+}
+
+static void __exit test_parman_exit(void)
+{
+}
+
+module_init(test_parman_init);
+module_exit(test_parman_exit);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
+MODULE_DESCRIPTION("Test module for parman");