Hi Ciprian, > -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of ciprian.barbu > Sent: Thursday, July 23, 2015 11:20 PM > To: dev at dpdk.org > Subject: Re: [dpdk-dev] can eth_igb_xmit_pkts called with len 0 affect > transmission? > > Anyone? > > On 17.07.2015 16:48, ciprian.barbu wrote: > > Hi, > > > > I'm seeing a strange behavior when calling rte_eth_tx_burst with len > > == 0. I'll explain the reason for this situation further bellow. But > > what I'm seeing is that after doing this call my application keeps > > returning from eth_igb_xmit_pkts here, even when len > 0: > > http://dpdk.org/browse/dpdk/tree/lib/librte_pmd_e1000/igb_rxtx.c?h=rel > > eases#n476 Don?t understand what the len means? The packet length? According to where the code returns, seems the queue is not initialized correctly. I saw you used odp-dpdk. Sorry, I'm not familiar with it. Why not try dpdk examples, and check if the behavior is same?
> > > > > > I can't really explain myself this behavior, I don't understand very > > well what the nic does once it receives buffers in its rings, but to > > me it looks like calling rte_eth_tx_burst with len 0 has this effect. > > > > What I'm using in my tests is the linaro odp-dpdk implementation and > > the odp_l2fwd example. The odp-dpdk implementation makes this call to > > try and make the pmd to flush the tx queue in case there are no more > > free buffers in the pool, but this was only verified for ixgbe 82599 > > cards, for igb the packets are not actually flushed until the tail > > circles back the whole length of the queue. I'm pretty much the only > > one (that I know > > of) that uses odp with 1G igb i350 cards and see this issue. > > > > Can anyone explain whether I'm getting this right and there could be > > side effects to calling eth_igb_xmit_pkts with len 0? > > > > Thank you, > > /Ciprian
