Hi all, with the 4.9.0-rt1 and also the 4.9.4-rt2 kernel (x86, 64bit) I observe a strange issue when running my multithreaded real time executable within gdb. Fairly often (in about 40% of all runs) the gdb stops executing with the message: Thread 8 "MDL07-Acknowled" received signal SIGSTOP, Stopped (signal). [Switching to Thread 0x7fffef141700 (LWP 9770)] 0x00007ffff535b24d in read () at ../sysdeps/unix/syscall-template.S:84 Often it helps to enter "continue" a couple of times to continue the debugging. However, sometimes it ends up in an endless loop of "continue" followed by a SIGSTOP, "continue", etc. If this issue occurs, the SIGSTOP is complained for all threads in the executable. Different system calls are affected: read, select, pselect, clone (via pthread_create), ... Debugging is more or less impossible due to this issue. No SIGSTOP is sent out by the application, the root cause for this signal is not clear to me. When I reconfigured the kernel to use "Preemptible Kernel (Basic RT)" I do not observer this issue. Also with kernel 3.18.42-rt44 (Fully Preemptible) it works fine. I never see this issue there. Any hints on how to solve the issue are highly appreciated. Thanks Best regards Mathias -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
