-----Original Message----- > When an event device is stopped, it drains all event queues. These events > may contain pointers, so to prevent memory leaks eventdev now supports a > user-provided flush callback that is called during the queue drain process. > This callback is stored in process memory, so the callback must be > registered by any process that may call rte_event_dev_stop(). > > This commit also clarifies the behavior of rte_event_dev_stop(). > > This follows this mailing list discussion: > http://dpdk.org/ml/archives/dev/2018-January/087484.html > > Signed-off-by: Gage Eads <gage.e...@intel.com> > --- > v2: allow a NULL callback pointer to unregister the callback > > lib/librte_eventdev/rte_eventdev.c | 17 +++++++++ > lib/librte_eventdev/rte_eventdev.h | 55 > +++++++++++++++++++++++++++- > lib/librte_eventdev/rte_eventdev_version.map | 6 +++ > 3 files changed, 76 insertions(+), 2 deletions(-) > > diff --git a/lib/librte_eventdev/rte_eventdev.c > b/lib/librte_eventdev/rte_eventdev.c > index 851a119..1aacb7b 100644 > --- a/lib/librte_eventdev/rte_eventdev.c > +++ b/lib/librte_eventdev/rte_eventdev.c > @@ -1123,6 +1123,23 @@ rte_event_dev_start(uint8_t dev_id) > return 0; > } > > +typedef void (*eventdev_stop_flush_t)(uint8_t dev_id, struct rte_event event, > + void *arg); > +/**< Callback function called during rte_event_dev_stop(), invoked once per > + * flushed event. > + */ > + > #define RTE_EVENTDEV_NAME_MAX_LEN (64) > /**< @internal Max length of name of event PMD */ > > @@ -1176,6 +1194,11 @@ struct rte_eventdev { > event_dequeue_burst_t dequeue_burst; > /**< Pointer to PMD dequeue burst function. */ > > + eventdev_stop_flush_t dev_stop_flush; > + /**< Optional, user-provided event flush function */ > + void *dev_stop_flush_arg; > + /**< User-provided argument for event flush function */ > +
I think, we can move this additions to the internal rte_eventdev_data structure. Reasons are 1) Changes to "struct rte_eventdev" would call for ABI change 2) We can keep "struct rte_eventdev" only for fast path functions, slow path functions can have additional redirection. > struct rte_eventdev_data *data; > /**< Pointer to device data */ > const struct rte_eventdev_ops *dev_ops; > @@ -1822,6 +1845,34 @@ rte_event_dev_xstats_reset(uint8_t dev_id, > */ > int rte_event_dev_selftest(uint8_t dev_id); > > +/** > + * Registers a callback function to be invoked during rte_event_dev_stop() > for > + * each flushed event. This function can be used to properly dispose of > queued > + * events, for example events containing memory pointers. > + * > + * The callback function is only registered for the calling process. The > + * callback function must be registered in every process that can call > + * rte_event_dev_stop(). > + * > + * To unregister a callback, call this function with a NULL callback pointer. > + * > + * @param dev_id > + * The identifier of the device. > + * @param callback > + * Callback function invoked once per flushed event. > + * @param userdata > + * Argument supplied to callback. > + * > + * @return > + * - 0 on success. > + * - -EINVAL if *dev_id* is invalid > + * > + * @see rte_event_dev_stop() > + */ > +int > +rte_event_dev_stop_flush_callback_register(uint8_t dev_id, > + eventdev_stop_flush_t callback, void *userdata); > + IMO, It would be better if we place this function near to rte_event_dev_stop(). Other than above minor changes, It looks good to me.
