On Mon, Nov 25, 2013 at 12:05 PM, Mateusz Guzik <mguzik@xxxxxxxxxx> wrote: > On Mon, Nov 25, 2013 at 11:53:24AM -0800, Shawn Landden wrote: >> On Mon, Nov 25, 2013 at 10:05 AM, Jason Baron <jbaron@xxxxxxxxxx> wrote: >> > On 11/22/2013 12:53 PM, Shawn Landden wrote: >> >> Hello, when running the attached program on 3.12 child processes >> >> are missing a socket fd opened, set with SO_REUSEPORT, listen()ed to, >> >> and added to epoll_ctl(). >> >> >> >> This is the output I get when pointing "wget http://localhost:5555/"; >> >> at the attached program: >> >> >> >> main PID 31591 >> >> PID 31634 started >> >> PID 31634 accept()ed connection >> >> PID 31635 started >> >> PID 31636 started >> >> PID 31635 accept() failed: Bad file descriptor >> >> PID 31636 accept() failed: Bad file descriptor >> >> PID 31634 accept()ed connection >> >> PID 31634 accept()ed connection >> >> PID 31634 accept()ed connection >> >> PID 31634 accept()ed connection >> >> >> >> >> >> While I would expect something like: >> >> >> >> main PID 31591 >> >> PID 31634 started >> >> PID 31634 accept()ed connection >> >> PID 31635 started >> >> PID 31636 started >> >> PID 31635 accept()ed connection >> >> PID 31636 accept()ed connection >> >> >> >> -more new processes, but inversely proportional to number of listening processes >> >> -accept() always returns successfully >> >> >> >> >> > >> > The 'close(sockfd);' looks to be racing with the accept() calls. Removing seems >> > to get the result you are looking for. >> Interesting. That works, but it shouldn't. The close() is operating in >> the parent, so it shouldn't affect the child, >> there is a leak here of process separation. >> > > You fork, then close sockfd in the parent. Thus, the very first child > can accept connectins just fine. > > Subsequent forks give you children without sockfd, thus accept fails. > The first child continues to work just fine. Now I feel like an idiot. -- --- Shawn Landden +1 360 389 3001 (SMS preferred) -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
