<div dir="ltr">Can you paste the output of "cat /proc/meminfo"?</div> <div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Mar 1, 2022 at 5:37 PM Lombardo, Ed <<a href="mailto:Ed.Lombardo@netscout.com">Ed.Lombardo@netscout.com</a>> wrote: </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Here is the output from rte_mempool_dump() after creating the mbuf " mbuf_pool_create (mbuf_seg_size=16512, nb_mbuf=32768, socket_id=0)": nb_mbuf_per_pool = 32768 mb_size = 16640 16512 * 32768 = 541,065,216 mempool <mbuf_pool_socket_0>@0x17f811400 flags=10 pool=0x17f791180 iova=0x80fe11400 nb_mem_chunks=1 size=32768 populated_size=32768 header_size=64 elt_size=16640 trailer_size=0 total_obj_size=16704 private_data_size=64 avg bytes/object=16704.000000 internal cache infos: cache_size=250 cache_count[0]=0 ... cache_count[126]=0 cache_count[127]=0 total_cache_count=0 common_pool_count=32768 no statistics available -----Original Message----- From: Stephen Hemminger <<a href="mailto:stephen@networkplumber.org" target="_blank">stephen@networkplumber.org</a>> Sent: Tuesday, March 1, 2022 5:46 PM To: Cliff Burdick <<a href="mailto:shaklee3@gmail.com" target="_blank">shaklee3@gmail.com</a>> Cc: Lombardo, Ed <<a href="mailto:Ed.Lombardo@netscout.com" target="_blank">Ed.Lombardo@netscout.com</a>>; <a href="mailto:users@dpdk.org" target="_blank">users@dpdk.org</a> Subject: Re: How to increase mbuf size in dpdk version 17.11 External Email: This message originated outside of NETSCOUT. Do not click links or open attachments unless you recognize the sender and know the content is safe. On Tue, 1 Mar 2022 13:37:07 -0800 Cliff Burdick <<a href="mailto:shaklee3@gmail.com" target="_blank">shaklee3@gmail.com</a>> wrote: > Can you verify how many buffers you're allocating? I don't see how > many you're allocating in this thread. > > On Tue, Mar 1, 2022 at 1:30 PM Lombardo, Ed <<a href="mailto:Ed.Lombardo@netscout.com" target="_blank">Ed.Lombardo@netscout.com</a>> > wrote: > > > Hi Stephen, > > The VM is configured to have 32 GB of memory. > > Will dpdk consume the 2GB of hugepage memory for the mbufs? > > I don't mind having less mbufs with mbuf size of 16K vs original > > mbuf size of 2K. > > > > Thanks, > > Ed > > > > -----Original Message----- > > From: Stephen Hemminger <<a href="mailto:stephen@networkplumber.org" target="_blank">stephen@networkplumber.org</a>> > > Sent: Tuesday, March 1, 2022 2:57 PM > > To: Lombardo, Ed <<a href="mailto:Ed.Lombardo@netscout.com" target="_blank">Ed.Lombardo@netscout.com</a>> > > Cc: <a href="mailto:users@dpdk.org" target="_blank">users@dpdk.org</a> > > Subject: Re: How to increase mbuf size in dpdk version 17.11 > > > > External Email: This message originated outside of NETSCOUT. Do not > > click links or open attachments unless you recognize the sender and > > know the content is safe. > > > > On Tue, 1 Mar 2022 18:34:22 +0000 > > "Lombardo, Ed" <<a href="mailto:Ed.Lombardo@netscout.com" target="_blank">Ed.Lombardo@netscout.com</a>> wrote: > > > > > Hi, > > > I have an application built with dpdk 17.11. > > > During initialization I want to change the mbuf size from 2K to 16K. > > > I want to receive packet sizes of 8K or more in one mbuf. > > > > > > The VM running the application is configured to have 2G hugepages. > > > > > > I tried many things and I get an error when a packet arrives. > > > > > > I read online that there is #define DEFAULT_MBUF_DATA_SIZE that I > > changed from 2176 to ((2048*8)+128), where 128 is for headroom. > > > The call to rte_pktmbuf_pool_create() returns success with my changes. > > > From the rte_mempool_dump() - "rx_nombuf" - Total number of Rx > > > mbuf > > allocation failures. This value increments each time a packet arrives. > > > > > > Is there any reference document explaining what causes this error? > > > Is there a user guide I should follow to make the mbuf size > > > change, > > starting with the hugepage value? > > > > > > Thanks, > > > Ed > > > > Did you check that you have enough memory in the system for the > > larger footprint? > > Using 16K per mbuf is going to cause lots of memory to be consumed. A little maths you can fill in your own values. Assuming you want 16K of data. You need at a minimum [1] num_rxq := total number of receive queues num_rxd := number of receive descriptors per receive queue num_txq := total number of transmit queues (assume all can be full) num_txd := number of transmit descriptors num_mbufs = num_rxq * num_rxd + num_txq * num_txd + num_cores * burst_size Assuming you are using code copy/pasted from some example like l3fwd. With 4 Rxq num_mbufs = 4 * 1024 + 4 * 1024 + 4 * 32 = 8320 Each mbuf element requires [2] elt_size = sizeof(struct rte_mbuf) + HEADROOM + mbuf_size = 128 + 128 + 16K = 16640 obj_size = rte_mempool_calc_obj_size(elt_size, 0, NULL) = 16832 So total pool is num_mbufs * obj_size = 8320 * 16832 = 140,042,240 ~ 139M [1] Some devices line bnxt need multiple buffers per packet. [2] Often applications want additional space per mbuf for meta-data. </blockquote></div>