Hi Tianlin Thanks very much for your inputs, I will investigate this issue and update to you after I have any findings.
Changchun > -----Original Message----- > From: Zhou, Tianlin [mailto:tianlin.zhou at tekcomms.com] > Sent: Friday, June 12, 2015 5:36 PM > To: dev at dpdk.org; Ouyang, Changchun > Subject: RE: Poor Virtio PMD TX Performance > > Hi Changchun, > > Thanks for your response. > Please see my embedded comments. > > What kind of vhost in your test? Linux vhost or dpdk user space vhost? > [tzhou] We use Linux vhost. > > Do you enable the dump/log in your test? It will decrease perf of vritio. > [tzhou] No, I did not enable dump/log in the performance testing. > I just opened log to debug why drop packets and then close it for higher > performance. > > > Which version of dpdk codes are you using? The tip codes in dpdk.org? > [tzhou] I used DPDK 2.0.0 and l2fwd in DPDK 2.0.0. > l2fwd start command: ./l2fwd -c 0x2 -n 1 --p 0x1 > > qemu start command (I used the virtio interface for RX/TX in GUEST): > sudo kvm -m 4096M -smp 4 -hda /home/geo/yanghe/fedora20.qcow2 -boot > d -daemonize -monitor \ telnet::10024,server,nowait,nodelay \ -cpu host \ - > device e1000,netdev=public0,mac=00:0c:29:e1:f3:ff -netdev > user,id=public0,hostfwd=tcp::11022-:22 \ -device virtio-net- > pci,netdev=public1,mac=00:0c:29:e1:ff:ff,ioeventfd=on -netdev > tap,id=public1,ifname=tapvm02,script=/home/geo/tzhou/kvm- > image/tup.sh,downscript=no,vhost=on > > The qemu version? > [tzhou] > root at dw-2:/home/geo/tzhou/kvm-image# kvm -version QEMU emulator > version 2.0.0 (Debian 2.0.0+dfsg-2ubuntu1.3), Copyright (c) 2003-2008 Fabrice > Bellard > > -Tianlin > > -----Original Message----- > From: Ouyang, Changchun [mailto:changchun.ouyang at intel.com] > Sent: Monday, June 08, 2015 10:13 AM > To: Zhou, Tianlin > Cc: Ouyang, Changchun > Subject: RE: Poor Virtio PMD TX Performance > > Hi tianlin, > > What kind of vhost in your test? Linux vhost or dpdk user space vhost? > > Do you enable the dump/log in your test? It will decrease perf of vritio. > > Which version of dpdk codes are you using? The tip codes in dpdk.org? > > The qemu version? > > Thanks for inputs > Changchun > > > > -----Original Message----- > > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Zhou, Tianlin > > Sent: Friday, June 5, 2015 5:23 PM > > To: dev at dpdk.org > > Subject: [dpdk-dev] Poor Virtio PMD TX Performance > > > > Hi there, > > > > We tested TX performance of Virtio PMD by DPDK l2fwd, but found even > > at 60KPPS (720B packet length) TX rate, there is 1/1000 packet dropping > rate. > > The log shows "No free tx descriptors to transmit" in Virtio PMD. > > Increasing TX queues by modifying DPDK l2fwd can decreases packet > > dropping rate, but can't ensure no packet dropping unless > > retransmitting packets that can't be sent successfully. > > Oppositely, RX rate can be 600KPPS without packet dropping. > > > > Test Env > > - Host CPU: 4 cores, 2127.770MHz > > - Host Memory: 8G > > - Host OS: Linux dw-2 3.13.0-24-generic #46-Ubuntu SMP Thu Apr 10 > > 19:11:08 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux > > - Guest CPU: 4 cores, 2127.770MHz > > - Guest Memory: 4G > > - Guest OS: fedora20 > > > > Anybody here face the same problem? > > > > -Tianlin
