> -----Original Message-----
> From: Guo, Jia
> Sent: Thursday, January 18, 2018 12:12 PM
> To: step...@networkplumber.org; Richardson, Bruce
> <bruce.richard...@intel.com>;
> Yigit, Ferruh <ferruh.yi...@intel.com>; gaetan.ri...@6wind.com
> Cc: Ananyev, Konstantin <konstantin.anan...@intel.com>; jblu...@infradead.org;
> shreyansh.j...@nxp.com; Wu, Jingjing <jingjing...@intel.com>; dev@dpdk.org;
> Guo, Jia
> <jia....@intel.com>; tho...@monjalon.net; Zhang, Helin
> <helin.zh...@intel.com>;
> mo...@mellanox.com
> Subject: [PATCH V12 1/3] eal: add uevent monitor api and callback func
>
> This patch aim to add a general uevent mechanism in eal device layer,
> to enable all linux kernel object uevent monitoring, user could use these
> APIs to monitor and read out the device status info that sent from the
> kernel side, then corresponding to handle it, such as when detect hotplug
> uevent type, user could detach or attach the device, and more it benefit
> to use to do smoothly fail safe work.
>
> About uevent monitoring:
> a: add one epolling to poll the netlink socket, to monitor the uevent of
> the device.
> b: add enum of rte_eal_dev_event_type and struct of rte_eal_uevent.
> c: add below APIs in rte eal device layer.
> rte_dev_callback_register
> rte_dev_callback_unregister
> _rte_dev_callback_process
> rte_dev_event_monitor_start
> rte_dev_event_monitor_stop
>
> Signed-off-by: Jeff Guo <jia....@intel.com>
> ---
> v12->v11:
> identify null param in callback for monitor all devices uevent
> ---
> lib/librte_eal/bsdapp/eal/eal_dev.c | 38 ++++++
> lib/librte_eal/common/eal_common_dev.c | 128 ++++++++++++++++++
> lib/librte_eal/common/include/rte_dev.h | 119 +++++++++++++++++
> lib/librte_eal/linuxapp/eal/Makefile | 1 +
> lib/librte_eal/linuxapp/eal/eal_dev.c | 223
> ++++++++++++++++++++++++++++++++
> 5 files changed, 509 insertions(+)
> create mode 100644 lib/librte_eal/bsdapp/eal/eal_dev.c
> create mode 100644 lib/librte_eal/linuxapp/eal/eal_dev.c
>
[......]
> +int
> +rte_dev_callback_register(char *device_name, rte_dev_event_cb_fn cb_fn,
> + void *cb_arg)
> +{
> + struct rte_dev_event_callback *event_cb = NULL;
> +
> + rte_spinlock_lock(&rte_dev_event_lock);
> +
> + if (TAILQ_EMPTY(&(dev_event_cbs)))
> + TAILQ_INIT(&(dev_event_cbs));
> +
> + TAILQ_FOREACH(event_cb, &(dev_event_cbs), next) {
> + if (event_cb->cb_fn == cb_fn &&
> + event_cb->cb_arg == cb_arg &&
> + !strcmp(event_cb->dev_name, device_name))
device_name = NULL means means for all devices, right? Can strcmp accept NULL
arguments?
> + break;
> + }
> +
> + /* create a new callback. */
> + if (event_cb == NULL) {
> + /* allocate a new user callback entity */
> + event_cb = malloc(sizeof(struct rte_dev_event_callback));
> + if (event_cb != NULL) {
> + event_cb->cb_fn = cb_fn;
> + event_cb->cb_arg = cb_arg;
> + event_cb->dev_name = device_name;
> + }
Is that OK to call TAILQ_INSERT_TAIL below if event_cb == NULL?
> + TAILQ_INSERT_TAIL(&(dev_event_cbs), event_cb, next);
> + }
> +
> + rte_spinlock_unlock(&rte_dev_event_lock);
> + return (event_cb == NULL) ? -1 : 0;
> +}
> +
> +int
> +rte_dev_callback_unregister(char *device_name, rte_dev_event_cb_fn cb_fn,
> + void *cb_arg)
> +{
> + int ret;
> + struct rte_dev_event_callback *event_cb, *next;
> +
> + if (!cb_fn || device_name == NULL)
> + return -EINVAL;
> +
> + rte_spinlock_lock(&rte_dev_event_lock);
> +
> + ret = 0;
> +
> + for (event_cb = TAILQ_FIRST(&(dev_event_cbs)); event_cb != NULL;
> + event_cb = next) {
> +
> + next = TAILQ_NEXT(event_cb, next);
> +
> + if (event_cb->cb_fn != cb_fn ||
> + (event_cb->cb_arg != (void *)-1 &&
> + event_cb->cb_arg != cb_arg) ||
> + strcmp(event_cb->dev_name, device_name))
The same comments as above.
> + continue;
> +
> + /*
> + * if this callback is not executing right now,
> + * then remove it.
> + */
> + if (event_cb->active == 0) {
> + TAILQ_REMOVE(&(dev_event_cbs), event_cb, next);
> + rte_free(event_cb);
> + } else {
> + ret = -EAGAIN;
> + }
> + }
> +
> + rte_spinlock_unlock(&rte_dev_event_lock);
> + return ret;
> +}
> +
[......]
> +int
> +rte_dev_event_monitor_start(void)
> +{
> + int ret;
> + struct rte_service_spec service;
> + uint32_t id;
> + const uint32_t sid = 0;
> +
> + if (!service_no_init)
> + return 0;
> +
> + uint32_t slcore_1 = rte_get_next_lcore(/* start core */ -1,
> + /* skip master */ 1,
> + /* wrap */ 0);
> +
> + ret = rte_service_lcore_add(slcore_1);
> + if (ret) {
> + RTE_LOG(ERR, EAL, "dev event monitor lcore add fail");
> + return ret;
> + }
> +
> + memset(&service, 0, sizeof(service));
> + snprintf(service.name, sizeof(service.name), DEV_EV_MNT_SERVICE_NAME);
> +
> + service.socket_id = rte_socket_id();
> + service.callback = dev_uev_monitoring;
> + service.callback_userdata = NULL;
> + service.capabilities = 0;
> + ret = rte_service_component_register(&service, &id);
> + if (ret) {
> + RTE_LOG(ERR, EAL, "Failed to register service %s "
> + "err = %" PRId32,
> + service.name, ret);
> + return ret;
> + }
> + ret = rte_service_runstate_set(sid, 1);
> + if (ret) {
> + RTE_LOG(ERR, EAL, "Failed to set the runstate of "
> + "the service");
Any rollback need to be done when fails?
> + return ret;
> + }
> + ret = rte_service_component_runstate_set(id, 1);
> + if (ret) {
> + RTE_LOG(ERR, EAL, "Failed to set the backend runstate"
> + " of a component");
> + return ret;
> + }
> + ret = rte_service_map_lcore_set(sid, slcore_1, 1);
> + if (ret) {
> + RTE_LOG(ERR, EAL, "Failed to enable lcore 1 on "
> + "dev event monitor service");
> + return ret;
> + }
> + rte_service_lcore_start(slcore_1);
> + service_no_init = false;
> + return 0;
> +}
> +
> +int
> +rte_dev_event_monitor_stop(void)
> +{
> + service_exit = true;
> + service_no_init = true;
> + return 0;
Are start and stop peer functions to call? If we call
rte_dev_event_monitor_start to start monitor and then call
rte_dev_event_monitor_stop to stop it, and then how to start again?
> +}
> --
> 2.7.4
