On Sat, Aug 28, 2021 at 11:04 AM Richard Guy Briggs <rgb@xxxxxxxxxx> wrote: > I did set a syscall filter for > -a exit,always -F arch=b64 -S io_uring_enter,io_uring_setup,io_uring_register -F key=iouringsyscall > and that yielded some records with a couple of orphans that surprised me > a bit. Without looking too closely at the log you sent, you can expect URING records without an associated SYSCALL record when the uring op is being processed in the io-wq or sqpoll context. In the io-wq case the processing is happening after the thread finished the syscall but before the execution context returns to userspace and in the case of sqpoll the processing is handled by a separate kernel thread with no association to a process thread. -- paul moore www.paul-moore.com