selftests/bpf: Add a test for objects stuck in free_by_rcu_ttracegrafted

Delete all elements of BPF_F_NO_PREALLOC hash map in one batch. The first
free_bulk() starts RCU tasks trace GP and the rest of the elements are
freed while it's in flight. Wait for call_rcu_ttrace_in_progress to clear
in bpf_mem_cache of every cpu and check that free_by_rcu_ttrace and
waiting_for_gp_ttrace lists are empty.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20260930095920.601738-4-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/scripts/jobserver-exec b/scripts/jobserver-exec
new file mode 100755
index 000000000..21b319e6c
--- /dev/null
+++ b/scripts/jobserver-exec
@@ -0,0 +1,35 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0+
+
+"""
+Determines how many parallel tasks "make" is expecting, as it is
+not exposed via any special variables, reserves them all, runs a subprocess
+with PARALLELISM environment variable set, and releases the jobs back again.
+
+See:
+    https://www.gnu.org/software/make/manual/html_node/POSIX-Jobserver.html#POSIX-Jobserver
+"""
+
+import os
+import sys
+
+LIB_DIR = "../tools/lib/python"
+SRC_DIR = os.path.dirname(os.path.realpath(__file__))
+
+sys.path.insert(0, os.path.join(SRC_DIR, LIB_DIR))
+
+from jobserver import JobserverExec                  # pylint: disable=C0415
+
+
+def main():
+    """Main program"""
+    if len(sys.argv) < 2:
+        name = os.path.basename(__file__)
+        sys.exit("usage: " + name +" command [args ...]\n" + __doc__)
+
+    with JobserverExec() as jobserver:
+        return jobserver.run(sys.argv[1:])
+
+
+if __name__ == "__main__":
+    sys.exit(main())