Very helpful, thanks a lot. It sure does seem to do the trick. On Mon, Oct 13, 2014 at 2:43 PM, Ananyev, Konstantin < konstantin.ananyev at intel.com> wrote:
> > > > -----Original Message----- > > From: Ananyev, Konstantin > > Sent: Monday, October 13, 2014 12:30 PM > > To: Ananyev, Konstantin > > Subject: FW: [dpdk-dev] Aligned RX data. > > > > > > > > From: Alex Markuze [mailto:alex at weka.io] > > Sent: Monday, October 13, 2014 9:47 AM > > To: Ananyev, Konstantin > > Cc: dev at dpdk.org > > Subject: Re: [dpdk-dev] Aligned RX data. > > > > Hi All, > > Is there a way to create a mempool such that all mbufs are aligned to X. > lets say X is 512. > > > > Thanks. > > > > For example something like that: > > struct rte_mempool * > mempool_xz1_create(uint32_t elt_num, int32_t socket_id) > { > struct rte_mempool *mp; > const struct rte_memzone *mz; > struct rte_mempool_objsz obj_sz; > uint32_t flags, elt_size, total_size; > size_t sz; > phys_addr_t pa; > void *va; > > /* mp element header_size==64B, trailer_size==0. */ > flags = MEMPOOL_F_NO_SPREAD; > > /* to make total element size of mp 2K. */ > elt_size = 2048 - 64; > > total_size = rte_mempool_calc_obj_size(elt_size, flags, &obj_sz); > sz = elt_num * total_size + 512; > > if ((mz = rte_memzone_reserve_aligned("xz1_obj", sz, socket_id, > 0, 512)) == NULL) > return (NULL); > > va = (char *)mz->addr + 512 - obj_sz.header_size; > pa = mz->phys_addr + 512 - obj_sz.header_size; > > mp = rte_mempool_xmem_create("xz1", elt_num, elt_size, > 256, sizeof(struct rte_pktmbuf_pool_private), > rte_pktmbuf_pool_init, NULL, > rte_pktmbuf_init, NULL, > socket_id, flags, va, &pa, > MEMPOOL_PG_NUM_DEFAULT, MEMPOOL_PG_SHIFT_MAX); > > return (mp); > } > > Each mbuf will be aligned on 512B boundary and 1856 (2K - 64B header - > 128B mbuf). > > Alternative way - is to provide your own element constructor instead of > rte_pktmbuf_init() for mempool_create. > And inside it align buf_addr and buf_physaddr. > Though in that case you have to set RTE_MBUF_REFCNT=n in your config. > That's why I'd say it is a not recommended. > > Konstantin > > > > > On Sat, Oct 11, 2014 at 5:04 PM, Alex Markuze <alex at weka.io> wrote: > > O.k, And how would I do that? > > I'm guessing there is something I can control in rte_pktmbuf_pool_init? > > I would appreciate If you could spare a word or two in the matter. > > > > On Tue, Oct 7, 2014 at 7:11 PM, Ananyev, Konstantin < > konstantin.ananyev at intel.com> wrote: > > > > > > > -----Original Message----- > > > From: Ananyev, Konstantin > > > Sent: Tuesday, October 07, 2014 5:03 PM > > > To: Ananyev, Konstantin > > > Subject: FW: [dpdk-dev] Aligned RX data. > > > > > > > > > > > > From: Alex Markuze [mailto:alex at weka.io] > > > Sent: Tuesday, October 07, 2014 4:52 PM > > > To: Ananyev, Konstantin > > > Cc: dev at dpdk.org > > > Subject: Re: [dpdk-dev] Aligned RX data. > > > > > > RTE_PKTMBUF_HEADROOM defines the headroom > > > > Yes. > > > > >this would be true only if the buff_start was aligned to 512 which is > not. > > > > As I said: " Make sure that your all your mbufs are aligned by 512". > > > > Konstantin > > > > > > > > On Tue, Oct 7, 2014 at 1:05 PM, Ananyev, Konstantin < > konstantin.ananyev at intel.com> wrote: > > > > > > > > > > -----Original Message----- > > > > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Alex Markuze > > > > Sent: Tuesday, October 07, 2014 10:40 AM > > > > To: dev at dpdk.org > > > > Subject: [dpdk-dev] Aligned RX data. > > > > > > > > Hi , I'm trying to receive aligned packets from the wire. > > > > Meaning that for all received packets the pkt.data is always aligned > to > > > > (512 -H). > > > > > > > > Looking at the pmds of ixgbe/vmxnet I see that the pmds call > > > > __rte_mbuf_raw_alloc and set the rx descriptor with a > > > > RTE_MBUF_DATA_DMA_ADDR_DEFAULT > > > > Instead of the more appropriate RTE_MBUF_DATA_DMA_ADDR. > > > > > > > > Do I need to modify each pmd I'm using to be able to receive aligned > data? > > > Make sure that your all your mbufs are aligned by 512 and set in your > config RTE_PKTMBUF_HEADROOM=512-H? > > > > > > > > > > Or have I missed something? > > > > > > > > Thanks > > > >
