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From: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>
To: "Wang, Zhihong" <zhihong.wang@intel.com>, "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v3 3/3] examples/l3fwd: Handle SIGINT and SIGTERM in l3fwd
Date: Wed, 30 Dec 2015 11:29:33 +0000	[thread overview]
Message-ID: <2601191342CEEE43887BDE71AB97725836ADF256@irsmsx105.ger.corp.intel.com> (raw)
In-Reply-To: <8F6C2BD409508844A0EFC19955BE09418645CE@SHSMSX103.ccr.corp.intel.com>



> -----Original Message-----
> From: Wang, Zhihong
> Sent: Wednesday, December 30, 2015 3:15 AM
> To: Ananyev, Konstantin; dev@dpdk.org
> Cc: stephen@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);
> > > +		}
> > > +	}
> > > +}
> > > +

  reply	other threads:[~2015-12-30 11:29 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-25  2:37 [dpdk-dev] [PATCH v2 0/3] Handle SIGINT and SIGTERM in DPDK examples Zhihong Wang
2015-12-25  2:37 ` [dpdk-dev] [PATCH v2 1/3] app/test-pmd: Handle SIGINT and SIGTERM in testpmd Zhihong Wang
2015-12-27 21:42   ` Stephen Hemminger
2015-12-28  1:37     ` Wang, Zhihong
2015-12-25  2:37 ` [dpdk-dev] [PATCH v2 2/3] examples/l2fwd: Handle SIGINT and SIGTERM in l2fwd Zhihong Wang
2015-12-27 21:49   ` Stephen Hemminger
2015-12-28  1:35     ` Wang, Zhihong
2015-12-25  2:37 ` [dpdk-dev] [PATCH v2 3/3] examples/l3fwd: Handle SIGINT and SIGTERM in l3fwd Zhihong Wang
2015-12-28  4:17 ` [dpdk-dev] [PATCH v2 0/3] Handle SIGINT and SIGTERM in DPDK examples Qiu, Michael
2015-12-28  9:51   ` Wang, Zhihong
2015-12-29  1:20 ` [dpdk-dev] [PATCH v3 " Zhihong Wang
2015-12-29  1:20   ` [dpdk-dev] [PATCH v3 1/3] app/test-pmd: Handle SIGINT and SIGTERM in testpmd Zhihong Wang
2015-12-29  1:20   ` [dpdk-dev] [PATCH v3 2/3] examples/l2fwd: Handle SIGINT and SIGTERM in l2fwd Zhihong Wang
2015-12-30 17:35     ` Stephen Hemminger
2015-12-29  1:20   ` [dpdk-dev] [PATCH v3 3/3] examples/l3fwd: Handle SIGINT and SIGTERM in l3fwd Zhihong Wang
2015-12-29 13:34     ` Ananyev, Konstantin
2015-12-30  3:15       ` Wang, Zhihong
2015-12-30 11:29         ` Ananyev, Konstantin [this message]
2015-12-31  2:14           ` Wang, Zhihong
2015-12-30 17:37     ` Stephen Hemminger
2015-12-29 23:27 ` [dpdk-dev] [PATCH v4 0/3] Handle SIGINT and SIGTERM in DPDK examples Zhihong Wang
2015-12-29 23:27   ` [dpdk-dev] [PATCH v4 1/3] app/test-pmd: Handle SIGINT and SIGTERM in testpmd Zhihong Wang
2015-12-29 23:27   ` [dpdk-dev] [PATCH v4 2/3] examples/l2fwd: Handle SIGINT and SIGTERM in l2fwd Zhihong Wang
2015-12-29 23:27   ` [dpdk-dev] [PATCH v4 3/3] examples/l3fwd: Handle SIGINT and SIGTERM in l3fwd Zhihong Wang
2015-12-30 13:37     ` Ananyev, Konstantin
2015-12-31  1:44       ` Wang, Zhihong
2015-12-31  2:09         ` Stephen Hemminger
2015-12-31  2:20           ` Wang, Zhihong
2015-12-30 21:59 ` [dpdk-dev] [PATCH v5 0/3] Handle SIGINT and SIGTERM in DPDK examples Zhihong Wang
2015-12-30 21:59   ` [dpdk-dev] [PATCH v5 1/3] app/test-pmd: Handle SIGINT and SIGTERM in testpmd Zhihong Wang
2015-12-30 21:59   ` [dpdk-dev] [PATCH v5 2/3] examples/l2fwd: Handle SIGINT and SIGTERM in l2fwd Zhihong Wang
2015-12-31 17:01     ` Stephen Hemminger
2016-01-04  2:00       ` Wang, Zhihong
2015-12-30 21:59   ` [dpdk-dev] [PATCH v5 3/3] examples/l3fwd: Handle SIGINT and SIGTERM in l3fwd Zhihong Wang
2016-01-06 13:51     ` Ananyev, Konstantin
2016-01-27 16:34   ` [dpdk-dev] [PATCH v5 0/3] Handle SIGINT and SIGTERM in DPDK examples Thomas Monjalon

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