On Tue, 31 Jan 2023, Shaopeng Tan wrote:
> After creating a child process with fork() in CAT test, if an error
> occurs or a signal such as SIGINT is received, the parent process will
> be terminated immediately, and therefor the child process will not
> be killed and also resctrlfs is not unmounted.
>
> There is a signal handler registered in CMT/MBM/MBA tests, which kills
> child process, unmount resctrlfs, cleanups result files, etc., if a
> signal such as SIGINT is received.
>
> Commonize the signal handler registered for CMT/MBM/MBA tests and reuse
> it in CAT too.
>
> To reuse the signal handler, make the child process in CAT wait to be
> killed by parent process in any case (an error occurred or a signal was
> received), and when killing child process use global bm_pid instead of
> local bm_pid.
>
> Also, since the MBA/MBA/CMT/CAT are run in order, unregister the signal
> handler at the end of each test so that the signal handler cannot be
> inherited by other tests.
>
> Signed-off-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxxxxx>
> ---
> if (bm_pid == 0) {
> /* Tell parent that child is ready */
> close(pipefd[0]);
> pipe_message = 1;
> if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) <
> - sizeof(pipe_message)) {
> - close(pipefd[1]);
> + sizeof(pipe_message))
> + /*
> + * Just print the error message.
> + * Let while(1) run and wait for itself to be killed.
> + */
> perror("# failed signaling parent process");
If the write error is ignored here, won't it just lead to parent hanging
forever waiting for the child to send the message through the pipe which
will never come?
--
i.
