kernel.git/tools/testing/selftests/bpf/prog_tests/free_timer.c, branch masterHosts the 0x221E linux distro kernel.
https://git.0xinfinity.dev/distro/kernel.git/atom?h=master2025-09-10T19:34:09Zselftests/bpf: Skip timer cases when bpf_timer is not supported2025-09-10T19:34:09ZLeon Hwang2025-09-10T12:57:40Zurn:sha1:fbdd61c94bcb09b0c0eb0655917bf4193d07aac1
When enable CONFIG_PREEMPT_RT, verifier will reject bpf_timer with
returning -EOPNOTSUPP.
Therefore, skip test cases when errno is EOPNOTSUPP.
cd tools/testing/selftests/bpf
./test_progs -t timer
125 free_timer:SKIP
456 timer:SKIP
457/1 timer_crash/array:SKIP
457/2 timer_crash/hash:SKIP
457 timer_crash:SKIP
458 timer_lockup:SKIP
459 timer_mim:SKIP
Summary: 5/0 PASSED, 6 SKIPPED, 0 FAILED
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20250910125740.52172-3-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
selftests/bpf: Add test case for the freeing of bpf_timer2025-01-20T17:09:02ZHou Tao2025-01-17T10:18:16Zurn:sha1:0a5d2efa382751fc2b0a9a82f6cbdfe8aef29fb3
The main purpose of the test is to demonstrate the lock problem for the
free of bpf_timer under PREEMPT_RT. When freeing a bpf_timer which is
running on other CPU in bpf_timer_cancel_and_free(), hrtimer_cancel()
will try to acquire a spin-lock (namely softirq_expiry_lock), however
the freeing procedure has already held a raw-spin-lock.
The test first creates two threads: one to start timers and the other to
free timers. The start-timers thread will start the timer and then wake
up the free-timers thread to free these timers when the starts complete.
After freeing, the free-timer thread will wake up the start-timer thread
to complete the current iteration. A loop of 10 iterations is used.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250117101816.2101857-6-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>