> -----Original Message----- > From: Jerin Jacob [mailto:jerin.ja...@caviumnetworks.com] > Sent: Monday, March 12, 2018 1:25 AM > To: Eads, Gage <gage.e...@intel.com> > Cc: dev@dpdk.org; Van Haaren, Harry <harry.van.haa...@intel.com>; > hemant.agra...@nxp.com; Richardson, Bruce <bruce.richard...@intel.com>; > santosh.shu...@caviumnetworks.com; nipun.gu...@nxp.com > Subject: Re: [PATCH v2 1/2] eventdev: add device stop flush callback > > -----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. >
Good points -- I hadn't considered the ABI impact of modifying rte_eventdev. rte_eventdev_data is in shared memory, though, so it's not multi-process friendly for function pointers. How about putting it in rte_eventdev_ops? > > 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. Ok, will address in v3. Thanks, Gage
