I tried this procedure as well as few others. at all of the procedures the HugePages_Free or HugePages_Rsvd doesn't change when creating the guest, though only AnonHugePages increases. I am struggling with it for a while without real success. I do suspect that this anonymous hugepages doesn't really make the job.
any idea? On Tue, Dec 27, 2016 at 8:52 PM Stephen Hemminger < [email protected]> wrote: > On Tue, 27 Dec 2016 15:59:08 +0000 > edgar helmut <[email protected]> wrote: > > > short explanation for how to read the comparison: > > first row is packet length > > throughput is half duplex, means: > > second row is vm throughput of port 1 to 2 (port 2 to 1 has approximately > > same throughput) in gbps. > > third row is host throughput of port 1 to 2 (port 2 to 1 has > approximately > > same throughput) in gbps. > > > > i.e. on 1500 bytes packet size testpmd delivers ~9.82 gbps from port 1 > to 2 > > and another ~9.82 gbps from port 2 to 1, while at the vm it only delivers > > ~3.9 gbps for each direction. > > > > > > On Tue, Dec 27, 2016 at 5:52 PM edgar helmut <[email protected]> > > wrote: > > > > > Thanks. That's the document i am following. > > > For the best i can only ask that the hugepages won't be shared with > > > others, but it never reserve it from the pre allocated hugepages of the > > > host. > > > Did you have a chance to use hugepages for a guest > > > > > > as for the interfaces, i am using the virtio/vhost which creates the > > > macvtap: > > > <interface type='direct' managed='yes'> > > > <source dev='ens6f0' mode='passthrough'/> > > > <model type='virtio'/> > > > <driver name='vhost' queues='2'/> > > > </driver> > > > <address type='pci' domain='0x0000' bus='0x04' slot='0x09' > > > function='0x0'/> > > > </interface> > > > > > > The following is a performance comparison host vs. vm using testpmd. as > > > you can see vm performance is poor. > > > > > > (sudo x86_64-native-linuxapp-gcc/app/testpmd -c 0x1f -n 3 -m 1024 -- > > > --coremask=0x1e --portmask=3 -i) > > > > > > > > > 64 128 256 500 800 1000 1500 > > > vm 0.23 0.42 0.75 1.3 2.3 2.7 3.9 > > > host 3.6 6.35 8.3 9.5 9.7 9.8 9.82 > > > > > > I have to improve it dramatically. > > > > > > > > > > > > On Mon, Dec 26, 2016 at 2:52 AM Hu, Xuekun <[email protected]> > wrote: > > > > > > Searching “hugepages” in https://libvirt.org/formatdomain.html > > > > > > > > > > > > If you are looking for to measure in and out packets through host, > maybe > > > you can look at vhost/virtio interface also. > > > > > > > > > > > > After your testing, if you can report the performace out with macvtap, > > > that also helps us. J > > > > > > > > > > > > > > > > > > *From:* edgar helmut [mailto:[email protected]] > > > *Sent:* Saturday, December 24, 2016 11:53 PM > > > > > > > > > *To:* Hu, Xuekun <[email protected]> > > > *Cc:* Wiles, Keith <[email protected]>; [email protected] > > > *Subject:* Re: [dpdk-users] Dpdk poor performance on virtual machine > > > > > > > > > > > > any idea how to reserve hugepages for a guest (and not > > > transparent/anonymous hugepages) ? > > > > > > i am using libvirt and any backing method I am trying results with > > > anonymous hugepage. > > > > > > disabling the transparent hugepages resulted without any hugepages. > > > > > > Thanks > > > > > > > > > > > > On Sat, Dec 24, 2016 at 10:06 AM edgar helmut < > [email protected]> > > > wrote: > > > > > > I am looking for a mean to measure in and out packets to and from the > vm > > > (without asking the vm itself). While pure passthrough doesn't expose > an > > > interface to query for in/out pkts the macvtap exposes such an > interface. > > > > > > As for the anonymous hugepages I was looking for a more flexible method > > > and I assumed there is no much difference. > > > > > > I will make the test with reserved hugepages. > > > > > > However is there any knowledge about macvtap performance issues when > > > delivering 5-6 gbps? > > > > > > > > > > > > Thanks > > > > > > > > > > > > > > > > > > On 24 Dec 2016 9:06 AM, "Hu, Xuekun" <[email protected]> wrote: > > > > > > Now your setup has a new thing, “macvtap”. I don’t know what’s the > > > performance of using macvtap. I only know it has much worse perf than > the > > > “real” pci pass-through. > > > > > > > > > > > > I also don’t know why you select such config for your setup, anonymous > > > huge pages and macvtap. Any specific purpose? > > > > > > > > > > > > I think you should get a baseline first, then to get how much perf > dropped > > > if using anonymous hugepages or macvtap。 > > > > > > 1. Baseline: real hugepage + real pci pass-through > > > > > > 2. Anon hugepages vs hugepages > > > > > > 3. Real pci pass-through vs. macvtap > > > > > > > > > > > > *From:* edgar helmut [mailto:[email protected]] > > > *Sent:* Saturday, December 24, 2016 3:23 AM > > > *To:* Hu, Xuekun <[email protected]> > > > *Cc:* Wiles, Keith <[email protected]>; [email protected] > > > > > > > > > *Subject:* Re: [dpdk-users] Dpdk poor performance on virtual machine > > > > > > > > > > > > Hello, > > > > > > I changed the setup but still performance are poor :( and I need your > help > > > to understand the root cause. > > > > > > the setup is (sorry for long description): > > > > > > (test equipment is pktgen using dpdk installed on a second physical > > > machine coonected with 82599 NICs) > > > > > > host: Intel(R) Xeon(R) CPU E5-2640 v4 @ 2.40GHz with single socket , > > > ubuntu 16.04, with 4 hugepages of 1G each. > > > > > > hypervizor (kvm): QEMU emulator version 2.5.0 > > > > > > guest: same cpu as host, created with 3 vcpus, using ubuntu 16.04 > > > > > > dpdk: tried 2.2, 16.04, 16.07, 16.11 - using testpmd and 512 pages of > 2M > > > each. > > > > > > guest total memory is 2G and all of it is backed by the host with > > > transparent hugepages (I can see the AnonHugePages consumed at guest > > > creation). This memory includes the 512 hugepages for the testpmd > > > application. > > > > > > I pinned and isolated the guest's vcpus (using kernel option isolcapu), > > > and could see clearly that the isolation functions well. > > > > > > > > > > > > 2 x 82599 NICs connected as passthrough using macvtap interfaces to the > > > guest, so the guest receives and forwards packets from one interface > to the > > > second and vice versa. > > > > > > at the guest I bind its interfaces using igb_uio. > > > > > > the testpmd at guest starts dropping packets at about ~800mbps between > > > both ports bi-directional using two vcpus for forwarding (one for the > > > application management and two for forwarding). > > > > > > at 1.2 gbps it drops a lot of packets. > > > > > > the same testpmd configuration on the host (between both 82599 NICs) > > > forwards about 5-6gbps on both ports bi-directional. > > > > > > I assumed that forwarding ~5-6 gbps between two ports should be > trivial, > > > so it will be great if someone can share its configuration for a tested > > > setup. > > > > > > Any further idea will be highly appreciated. > > > > > > > > > > > > Thanks. > > > > > > > > > > > > On Sat, Dec 17, 2016 at 2:56 PM edgar helmut < > [email protected]> > > > wrote: > > > > > > That's what I afraid. > > > > > > In fact i need the host to back the entire guest's memory with > hugepages. > > > > > > I will find the way to do that and make the testing again. > > > > > > > > > > > > > > > > > > On 16 Dec 2016 3:14 AM, "Hu, Xuekun" <[email protected]> wrote: > > > > > > You said VM’s memory was 6G, while transparent hugepages was only used > ~4G > > > (4360192KB). So some were mapped to 4K pages. > > > > > > > > > > > > BTW, the memory used by transparent hugepage is not the hugepage you > > > reserved in kernel boot option. > > > > > > > > > > > > *From:* edgar helmut [mailto:[email protected]] > > > *Sent:* Friday, December 16, 2016 1:24 AM > > > *To:* Hu, Xuekun > > > *Cc:* Wiles, Keith; [email protected] > > > *Subject:* Re: [dpdk-users] Dpdk poor performance on virtual machine > > > > > > > > > > > > in fact the vm was created with 6G RAM, its kernel boot args are > defined > > > with 4 hugepages of 1G each, though when starting the vm i noted that > > > anonhugepages increased. > > > > > > The relevant qemu process id is 6074, and the following sums the > amount of > > > allocated AnonHugePages: > > > sudo grep -e AnonHugePages /proc/6074/smaps | awk '{ if($2>0) print > $2} > > > '|awk '{s+=$1} END {print s}' > > > > > > which results with 4360192 > > > > > > so not all the memory is backed with transparent hugepages though it is > > > more than the amount of hugepages the guest supposed to boot with. > > > > > > How can I be sure that the required 4G hugepages are really allocated?, > > > and not, for example, only 2G out of the 4G are allocated (and the > rest 2 > > > are mapping of the default 4K)? > > > > > > > > > > > > thanks > > > > > > > > > > > > On Thu, Dec 15, 2016 at 4:33 PM, Hu, Xuekun <[email protected]> > wrote: > > > > > > Are you sure the anonhugepages size was equal to the total VM's memory > > > size? > > > Sometimes, transparent huge page mechanism doesn't grantee the app is > using > > > the real huge pages. > > > > > > > > > > > > -----Original Message----- > > > From: users [mailto:[email protected]] On Behalf Of edgar helmut > > > Sent: Thursday, December 15, 2016 9:32 PM > > > To: Wiles, Keith > > > Cc: [email protected] > > > Subject: Re: [dpdk-users] Dpdk poor performance on virtual machine > > > > > > I have one single socket which is Intel(R) Xeon(R) CPU E5-2640 v4 @ > > > 2.40GHz. > > > > > > I just made two more steps: > > > 1. setting iommu=pt for better usage of the igb_uio > > > 2. using taskset and isolcpu so now it looks like the relevant dpdk > cores > > > use dedicated cores. > > > > > > It improved the performance though I still see significant difference > > > between the vm and the host which I can't fully explain. > > > > > > any further idea? > > > > > > Regards, > > > Edgar > > > > > > > > > On Thu, Dec 15, 2016 at 2:54 PM, Wiles, Keith <[email protected]> > > > wrote: > > > > > > > > > > > > On Dec 15, 2016, at 1:20 AM, edgar helmut < > [email protected]> > > > > wrote: > > > > > > > > > > Hi. > > > > > Some help is needed to understand performance issue on virtual > machine. > > > > > > > > > > Running testpmd over the host functions well (testpmd forwards 10g > > > > between > > > > > two 82599 ports). > > > > > However same application running on a virtual machine over same > host > > > > > results with huge degradation in performance. > > > > > The testpmd then is not even able to read 100mbps from nic without > > > drops, > > > > > and from a profile i made it looks like a dpdk application runs > more > > > than > > > > > 10 times slower than over host… > > > > > > > > Not sure I understand the overall setup, but did you make sure the > > > NIC/PCI > > > > bus is on the same socket as the VM. If you have multiple sockets on > your > > > > platform. If you have to access the NIC across the QPI it could > explain > > > > some of the performance drop. Not sure that much drop is this > problem. > > > > > > > > > > > > > > Setup is ubuntu 16.04 for host and ubuntu 14.04 for guest. > > > > > Qemu is 2.3.0 (though I tried with a newer as well). > > > > > NICs are connected to guest using pci passthrough, and guest's cpu > is > > > set > > > > > as passthrough (same as host). > > > > > On guest start the host allocates transparent hugepages > (AnonHugePages) > > > > so > > > > > i assume the guest memory is backed with real hugepages on the > host. > > > > > I tried binding with igb_uio and with uio_pci_generic but both > results > > > > with > > > > > same performance. > > > > > > > > > > Due to the performance difference i guess i miss something. > > > > > > > > > > Please advise what may i miss here? > > > > > Is this a native penalty of qemu?? > > > > > > > > > > Thanks > > > > > Edgar > > Did you setup KVM host to run guest in huge pages? > > https://access.redhat.com/solutions/36741 >
