Hi Alexei, On 12/10/2023 10:11 AM, Alexei Starovoitov wrote: > On Fri, Dec 8, 2023 at 2:22 AM Hou Tao <houtao@xxxxxxxxxxxxxxx> wrote: >> + /* Wait for any running non-sleepable and sleepable BPF programs to >> + * complete, so that userspace, when we return to it, knows that all >> + * programs that could be running use the new map value. > which could be forever... and the user space task doing simple map update > will never know why it got stuck in syscall waiting... forever... > synchronous waiting for tasks_trace is never an option. Could you please elaborate the reason why there is dead-lock problem ? In my naive understanding, synchronize_rcu_tasks_trace() only waits for the end of rcu_read_lock_trace()/rcu_read_unlock_trace(), if there is no rcu_read_lock_trace being held, there will be no dead-lock.
