Thank you for pointing out my problem, I will fix it in the next version > 2021年12月22日 下午7:45，Morten Brørup 写道： > >> From: Zhiheng Chen [mailto:chenzhiheng0227@gmail.com ] >> Sent: Wednesday, 22 December 2021 09.26 >> >> Compared to patch version 1, this version updates the descriptions >> of underlying functions. > > Some comments inline below, regarding the return value of success. > > You should also update the description of the dequeue function prototype on line 451, so no one implements an alternative dequeue operation that returns anything else than -ENOBUFS as error value. > > @Olivier, @Andrew: Do we want to impose this restriction on the API? > > Otherwise, the patch should take the opposite direction, and update the descriptions of high level functions - i.e. rte_mempool_generic_get(), rte_mempool_get_bulk(), rte_mempool_get(), etc. - to reflect that any error value <0 can be returned, originating from the underlying function. > >> >> In rte_mempool_ring.c, the committer uses the symbol ENOBUFS to >> describe the return value of function common_ring_sc_dequeue, >> but in rte_mempool.h, the symbol ENOENT is used to describe >> the return value of function rte_mempool_get. If the user of >> dpdk uses the symbol ENOENT as the judgment condition of >> the return value, it may cause some abnormal phenomena >> in their own programs, such as when the mempool space is exhausted. >> >> Fixes: ea5dd2744b90 ("mempool: cache optimisations") >> >> Signed-off-by: Zhiheng Chen >> --- >> lib/mempool/rte_mempool.h | 22 +++++++++++----------- >> 1 file changed, 11 insertions(+), 11 deletions(-) >> >> diff --git a/lib/mempool/rte_mempool.h b/lib/mempool/rte_mempool.h >> index 1e7a3c1527..3b52bd6737 100644 >> --- a/lib/mempool/rte_mempool.h >> +++ b/lib/mempool/rte_mempool.h >> @@ -737,8 +737,8 @@ rte_mempool_ops_alloc(struct rte_mempool *mp); >> * @param n >> * Number of objects to get. >> * @return >> - * - 0: Success; got n objects. >> - * - <0: Error; code of dequeue function. >> + * - >=0: Success; number of objects supplied. >> + * - -ENOBUFS: Not enough entries in the mempool; no object is >> retrieved. > > NAK regarding success: Return value 0 is correct, >=0 cannot happen. > >> */ >> static inline int >> rte_mempool_ops_dequeue_bulk(struct rte_mempool *mp, >> @@ -1453,7 +1453,7 @@ rte_mempool_put(struct rte_mempool *mp, void >> *obj) >> * A pointer to a mempool cache structure. May be NULL if not >> needed. >> * @return >> * - >=0: Success; number of objects supplied. > > This is also wrong. It should be: > -* - >=0: Success; number of objects supplied. > +* - 0: Success; got n objects. > >> - * - <0: Error; code of ring dequeue function. >> + * - -ENOBUFS: Not enough entries in the mempool; no object is >> retrieved. >> */ >> static __rte_always_inline int >> rte_mempool_do_generic_get(struct rte_mempool *mp, void **obj_table, >> @@ -1521,7 +1521,7 @@ rte_mempool_do_generic_get(struct rte_mempool >> *mp, void **obj_table, >> * Get several objects from the mempool. >> * >> * If cache is enabled, objects will be retrieved first from cache, >> - * subsequently from the common pool. Note that it can return -ENOENT >> when >> + * subsequently from the common pool. Note that it can return -ENOBUFS >> when >> * the local cache and common pool are empty, even if cache from other >> * lcores are full. >> * >> @@ -1534,8 +1534,8 @@ rte_mempool_do_generic_get(struct rte_mempool >> *mp, void **obj_table, >> * @param cache >> * A pointer to a mempool cache structure. May be NULL if not >> needed. >> * @return >> - * - 0: Success; objects taken. >> - * - -ENOENT: Not enough entries in the mempool; no object is >> retrieved. >> + * - >=0: Success; number of objects supplied. >> + * - -ENOBUFS: Not enough entries in the mempool; no object is >> retrieved. > > NAK regarding success: Return value 0 is correct, >=0 cannot happen. > >> */ >> static __rte_always_inline int >> rte_mempool_generic_get(struct rte_mempool *mp, void **obj_table, >> @@ -1557,7 +1557,7 @@ rte_mempool_generic_get(struct rte_mempool *mp, >> void **obj_table, >> * mempool creation time (see flags). >> * >> * If cache is enabled, objects will be retrieved first from cache, >> - * subsequently from the common pool. Note that it can return -ENOENT >> when >> + * subsequently from the common pool. Note that it can return -ENOBUFS >> when >> * the local cache and common pool are empty, even if cache from other >> * lcores are full. >> * >> @@ -1568,8 +1568,8 @@ rte_mempool_generic_get(struct rte_mempool *mp, >> void **obj_table, >> * @param n >> * The number of objects to get from the mempool to obj_table. >> * @return >> - * - 0: Success; objects taken >> - * - -ENOENT: Not enough entries in the mempool; no object is >> retrieved. >> + * - >=0: Success; number of objects supplied. >> + * - -ENOBUFS: Not enough entries in the mempool; no object is >> retrieved. > > NAK regarding success: Return value 0 is correct, >=0 cannot happen. > >> */ >> static __rte_always_inline int >> rte_mempool_get_bulk(struct rte_mempool *mp, void **obj_table, >> unsigned int n) >> @@ -1588,7 +1588,7 @@ rte_mempool_get_bulk(struct rte_mempool *mp, void >> **obj_table, unsigned int n) >> * mempool creation (see flags). >> * >> * If cache is enabled, objects will be retrieved first from cache, >> - * subsequently from the common pool. Note that it can return -ENOENT >> when >> + * subsequently from the common pool. Note that it can return -ENOBUFS >> when >> * the local cache and common pool are empty, even if cache from other >> * lcores are full. >> * >> @@ -1598,7 +1598,7 @@ rte_mempool_get_bulk(struct rte_mempool *mp, void >> **obj_table, unsigned int n) >> * A pointer to a void * pointer (object) that will be filled. >> * @return >> * - 0: Success; objects taken. >> - * - -ENOENT: Not enough entries in the mempool; no object is >> retrieved. >> + * - -ENOBUFS: Not enough entries in the mempool; no object is >> retrieved. >> */ >> static __rte_always_inline int >> rte_mempool_get(struct rte_mempool *mp, void **obj_p) >> -- >> 2.32.0