apport information ** Attachment added: "ProcCpuinfo.txt" https://bugs.launchpad.net/bugs/1960826/+attachment/5561019/+files/ProcCpuinfo.txt
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1960826 Title: NFSv4 performance problem with newer kernels Status in linux package in Ubuntu: Confirmed Bug description: I am seeing an issue with NFSv4 performance on Ubuntu 20.04.3 LTS on both clients and server (tested kernels 5.4 to 5.16), where the server is connected by 10Gbit Ethernet and with multiple clients connected by 1Gbit. I am reading a large file from an NFS mount via "dd" sending output to /dev/null with bs=4096. Using default sysctl and mount options I am seeing speeds maxing out below 1Gbit/sec. If I force NFSv3 I see speeds close to 10Gbit/sec with sufficient clients connected. I also see no issue with Ubuntu 16.04 (when used for both server and clients) in conjunction with NFSv4. I have attached the output from two iftop's which shows the status when using NFSv4 and when using NFSv3, in the NFSv4 you can clearly see one client reading at max speed and all the others apparently throttling back to practically nothing. I have additionally tested a range of mount options, which made no difference, BBR congestion control which made no difference and the following kernel settings which also made no difference: net.core.netdev_max_backlog=250000 net.core.rmem_max=4194304 net.core.wmem_max=4194304 net.core.rmem_default=4194304 net.core.wmem_default=4194304 net.core.optmem_max=4194304 net.ipv4.tcp_rmem=4096 87380 4194304 net.ipv4.tcp_wmem=4096 65536 4194304 net.ipv4.tcp_mem=786432 1048576 26777216 net.ipv4.udp_mem=1529892 2039859 3059784 net.ipv4.udp_rmem_min=16384 net.ipv4.udp_wmem_min=16384 The problem is seen on dissimilar hardware, ie this problem exists when testing with an HP DL380 G10 with Mellanox 10Gbit Ethernet connected to Cisco switch, and also on a Dell R430 with Broadcom 10Gbit Ethernet connected to a Netgear switch (just to name two of several configurations that have been tested). The clients vary in each test case also, but are desktop PCs and laptops. --- ProblemType: Bug AlsaDevices: total 0 crw-rw----+ 1 root audio 116, 1 Feb 15 10:23 seq crw-rw----+ 1 root audio 116, 33 Feb 15 10:23 timer AplayDevices: Error: [Errno 2] No such file or directory: 'aplay' ApportVersion: 2.20.11-0ubuntu27.21 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord' AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CasperMD5CheckResult: pass DistroRelease: Ubuntu 20.04 InstallationDate: Installed on 2022-02-14 (0 days ago) InstallationMedia: Ubuntu-Server 20.04.2 LTS "Focal Fossa" - Release amd64 (20210201.2) IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig' MachineType: Dell Inc. PowerEdge R430 Package: linux (not installed) PciMultimedia: ProcEnviron: TERM=xterm PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 mgag200drmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.13.0-28-generic root=UUID=d227a745-134e-4633-9c26-bcc062655f95 ro ProcVersionSignature: Ubuntu 5.13.0-28.31~20.04.1-generic 5.13.19 RelatedPackageVersions: linux-restricted-modules-5.13.0-28-generic N/A linux-backports-modules-5.13.0-28-generic N/A linux-firmware 1.187.26 RfKill: Error: [Errno 2] No such file or directory: 'rfkill' Tags: focal uec-images Uname: Linux 5.13.0-28-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: N/A _MarkForUpload: True dmi.bios.date: 06/07/2021 dmi.bios.release: 2.13 dmi.bios.vendor: Dell Inc. dmi.bios.version: 2.13.0 dmi.board.name: 0CN7X8 dmi.board.vendor: Dell Inc. dmi.board.version: A04 dmi.chassis.type: 23 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr2.13.0:bd06/07/2021:br2.13:svnDellInc.:pnPowerEdgeR430:pvr:rvnDellInc.:rn0CN7X8:rvrA04:cvnDellInc.:ct23:cvr:skuSKU=NotProvided;ModelName=PowerEdgeR430: dmi.product.name: PowerEdge R430 dmi.product.sku: SKU=NotProvided;ModelName=PowerEdge R430 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1960826/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
