> -----Original Message----- > From: Wang, Zhihong > Sent: Wednesday, December 30, 2015 3:15 AM > To: Ananyev, Konstantin; dev at dpdk.org > Cc: stephen at networkplumber.org; Qiu, Michael > Subject: RE: [PATCH v3 3/3] examples/l3fwd: Handle SIGINT and SIGTERM in l3fwd > > > > +static uint8_t > > > +start_ports(void) > > > +{ > > > + unsigned portid, nb_ports, avail_ports; > > > + int ret; > > > + > > > + nb_ports = rte_eth_dev_count(); > > > + avail_ports = 0; > > > + for (portid = 0; portid < nb_ports; portid++) { > > > + if ((enabled_port_mask & (1 << portid)) == 0) > > > + continue; > > > + avail_ports++; > > > + port_started = true; > > > > Why do you need it at each iteration? > > Only become true when the first enabled port about to started. In case > there's no port enabled at all. > In my opinion no need to optimize since it's not performance sensitive and > the logic is correct :) > > > > > > > + printf("Starting port %d...", portid); > > > + ret = rte_eth_dev_start(portid); > > > + if (ret < 0) > > > + rte_exit(EXIT_FAILURE, > > > + "rte_eth_dev_start: err=%d, port=%d\n", > > > + ret, portid); > > > + /* > > > + * If enabled, put device in promiscuous mode. > > > + * This allows IO forwarding mode to forward packets > > > + * to itself through 2 cross-connected ports of the > > > + * target machine. > > > + */ > > > + if (promiscuous_on) > > > + rte_eth_promiscuous_enable(portid); > > > + printf(" Done\n"); > > > + } > > > + > > > + return avail_ports; > > > +} > > [...] > > > > +static void > > > +signal_handler(int signum) > > > +{ > > > + if (signum == SIGINT || signum == SIGTERM) { > > > + printf("\nSignal %d received, preparing to exit...\n", > > > + signum); > > > + if (port_started) { > > > + printf("Ports started already...\n"); > > > + signo_quit = signum; > > > + force_quit = true; > > > + } else { > > > > > > Hmm, and what if signal_handler() would be executed not in the context of > > master lcore? > > Then there could be a raise condition, and you could end up here, while > > master > > lcore would be in the middle of start_ports()->rte_eth_dev_start(). > > Good point! Then we need rte_atomic16_cmpset() to avoid the race condition. > > > > Probably not a big deal, but why do you need this if (port_started) {...} > > else {...} > > at all? > > Why not just: > > If no port has been started, then just kill itself. > This is for cases like when you just started it and then want to shut it > down, it'll wait a long time for initialization (memory, etc.) before > the force_quit signal take effect.
Do you mean rte_eal_init()? Then why not to install non-default signal handlers after rte_eal_init()? Konstantin > > > > > > signal_handler(int signum) > > { > > signo_quit = signum; > > force_quit = true; > > } > > ? > > > > Konstantin > > > > > + printf("Ports not started yet...\n"); > > > + printf("Bye...\n"); > > > + /* exit with the expected status */ > > > + signal(signum, SIG_DFL); > > > + kill(getpid(), signum); > > > + } > > > + } > > > +} > > > +