The patch titled
Subject: maple_tree: add test for expanding range in RCU mode
has been added to the -mm mm-unstable branch. Its filename is
maple_tree-add-test-for-expanding-range-in-rcu-mode.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-add-test-for-expanding-range-in-rcu-mode.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
Subject: maple_tree: add test for expanding range in RCU mode
Date: Wed, 28 Jun 2023 15:36:55 +0800
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@xxxxxxxxxxxxx
Signed-off-by: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
Reviewed-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/radix-tree/maple.c | 75 +++++++++++++++++++++++++++++
1 file changed, 75 insertions(+)
--- a/tools/testing/radix-tree/maple.c~maple_tree-add-test-for-expanding-range-in-rcu-mode
+++ a/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
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_th
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);
_
Patches currently in -mm which might be from zhangpeng.00@xxxxxxxxxxxxx are
maple_tree-add-test-for-mas_wr_modify-fast-path.patch
maple_tree-add-test-for-expanding-range-in-rcu-mode.patch
maple_tree-optimize-mas_wr_append-also-improve-duplicating-vmas.patch
maple_tree-add-a-fast-path-case-in-mas_wr_slot_store.patch
