idr test suite: Create anchor before launching throbber

The throbber could race with creation of the anchor entry and cause the
IDR to have zero entries in it, which would cause the test to fail.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

diff --git a/tools/testing/radix-tree/idr-test.c b/tools/testing/radix-tree/idr-test.c
index 4a9b451b7ba031b2dab8ec7cd985f3fdb52144eb..6ce7460f3c7a9caf60da686f22693bd2ebba0346 100644 (file)
--- a/tools/testing/radix-tree/idr-test.c
+++ b/tools/testing/radix-tree/idr-test.c
@@ -301,11 +301,11 @@ void idr_find_test_1(int anchor_id, int throbber_id)
        pthread_t throbber;
        time_t start = time(NULL);
 
-       pthread_create(&throbber, NULL, idr_throbber, &throbber_id);
-
        BUG_ON(idr_alloc(&find_idr, xa_mk_value(anchor_id), anchor_id,
                                anchor_id + 1, GFP_KERNEL) != anchor_id);
 
+       pthread_create(&throbber, NULL, idr_throbber, &throbber_id);
+
        rcu_read_lock();
        do {
                int id = 0;