From c38d9ff2cc6777f7dc5c02fcb4842402ab5f362a Mon Sep 17 00:00:00 2001 From: Peng Zhang Date: Wed, 28 Jun 2023 15:36:55 +0800 Subject: [PATCH] maple_tree: add test for expanding range in RCU mode Add test for expanding range in RCU mode. If we use the fast path of the slot store to expand range in RCU mode, this test will fail. Link: https://lkml.kernel.org/r/20230628073657.75314-3-zhangpeng.00@bytedance.com Signed-off-by: Peng Zhang Reviewed-by: Liam R. Howlett Signed-off-by: Andrew Morton --- tools/testing/radix-tree/maple.c | 75 ++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) diff --git a/tools/testing/radix-tree/maple.c b/tools/testing/radix-tree/maple.c index 75ea2081a317..9901ae821911 100644 --- a/tools/testing/radix-tree/maple.c +++ b/tools/testing/radix-tree/maple.c @@ -45,6 +45,13 @@ struct rcu_test_struct2 { unsigned long last[RCU_RANGE_COUNT]; }; +struct rcu_test_struct3 { + struct maple_tree *mt; + unsigned long index; + unsigned long last; + bool stop; +}; + struct rcu_reader_struct { unsigned int id; int mod; @@ -34954,6 +34961,70 @@ void run_check_rcu(struct maple_tree *mt, struct rcu_test_struct *vals) MT_BUG_ON(mt, !vals->seen_entry2); } +static void *rcu_slot_store_reader(void *ptr) +{ + struct rcu_test_struct3 *test = ptr; + MA_STATE(mas, test->mt, test->index, test->index); + + rcu_register_thread(); + + rcu_read_lock(); + while (!test->stop) { + mas_walk(&mas); + /* The length of growth to both sides must be equal. */ + RCU_MT_BUG_ON(test, (test->index - mas.index) != + (mas.last - test->last)); + } + rcu_read_unlock(); + + rcu_unregister_thread(); + return NULL; +} + +static noinline void run_check_rcu_slot_store(struct maple_tree *mt) +{ + pthread_t readers[20]; + int range_cnt = 200, i, limit = 10000; + unsigned long len = ULONG_MAX / range_cnt, start, end; + struct rcu_test_struct3 test = {.stop = false, .mt = mt}; + + start = range_cnt / 2 * len; + end = start + len - 1; + test.index = start; + test.last = end; + + for (i = 0; i < range_cnt; i++) { + mtree_store_range(mt, i * len, i * len + len - 1, + xa_mk_value(i * 100), GFP_KERNEL); + } + + mt_set_in_rcu(mt); + MT_BUG_ON(mt, !mt_in_rcu(mt)); + + for (i = 0; i < ARRAY_SIZE(readers); i++) { + if (pthread_create(&readers[i], NULL, rcu_slot_store_reader, + &test)) { + perror("creating reader thread"); + exit(1); + } + } + + usleep(5); + + while (limit--) { + /* Step by step, expand the most middle range to both sides. */ + mtree_store_range(mt, --start, ++end, xa_mk_value(100), + GFP_KERNEL); + } + + test.stop = true; + + while (i--) + pthread_join(readers[i], NULL); + + mt_validate(mt); +} + static noinline void run_check_rcu_slowread(struct maple_tree *mt, struct rcu_test_struct *vals) { @@ -35206,6 +35277,10 @@ static noinline void __init check_rcu_threaded(struct maple_tree *mt) run_check_rcu(mt, &vals); mtree_destroy(mt); + /* Check expanding range in RCU mode */ + mt_init_flags(mt, MT_FLAGS_ALLOC_RANGE); + run_check_rcu_slot_store(mt); + mtree_destroy(mt); /* Forward writer for rcu stress */ mt_init_flags(mt, MT_FLAGS_ALLOC_RANGE); -- 2.34.1