On Sat, Aug 28, 2021 at 11:04 AM Richard Guy Briggs [off-list ref] 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