I found the answer in the comments: "/* Creates a shallow copy of mbuf */" for the rte_pktmbuf_clone. Thanks On Fri, Sep 1, 2023 at 4:31 PM omer yamac wrote: > Thank you for the clarification. Now, I understand more clearly. May I ask > one more question? I used the rte_pktmbuf_clone function to duplicate the > packet. Then, the new packet is cloned to the indirect memory. After the > clone, I used the RTE_MBUF_DIRECT macro to check this, which returns false. > So, to get a direct buffer, I need to use the alloc function and copy the > data. Am I right? > > I just want to use the "static inline int rte_vlan_insert(struct rte_mbuf > **m)" function; a direct buffer is necessary for this function. > > On Fri, Sep 1, 2023 at 4:08 PM Thomas Monjalon > wrote: > >> 01/09/2023 14:47, omer yamac: >> > Hello, >> > >> > I need clarification while creating direct/indirect buffers for mbuf. I >> > couldn't find exact documentation, and I just looked over the >> fragmentation >> > test case and saw that two pools were created. One is a >> > direct pool, and the other is an indirect pool. Here are the methods to >> > create pools: >> > direct_pool = rte_pktmbuf_pool_create("FRAG_D_MBUF_POOL", >> > NUM_MBUFS, BURST, 0, >> > RTE_MBUF_DEFAULT_BUF_SIZE, >> > SOCKET_ID_ANY); >> > indirect_pool = rte_pktmbuf_pool_create("FRAG_I_MBUF_POOL", >> > NUM_MBUFS, BURST, 0, >> > 0, SOCKET_ID_ANY) >> > >> > I couldn't see the exact difference. Just the "data_room_size" >> parameter is >> > different. If this parameter is 0, then is the pool indirect? >> >> A pool is neither direct or indirect, it is just a pool of buffers >> with a defined size for all buffers of a pool. >> You are free to create any pool for your needs. >> >> Now if you create a pool of buffers with size 0, >> we can expect you will save some data elsewhere, >> using rte_pktmbuf_attach_extbuf() for instance. >> >> More explanations can be found in the doc: >> >> https://doc.dpdk.org/guides/prog_guide/mbuf_lib.html#direct-and-indirect-buffers >> >> >>