Hi, I was doing a last minute regression test of the ext4 tree before sending a pull request to Linus, which I do using gce-xfstests[1], and I found that using networking was broken on GCE on linux-next. I was using next-20161209, and after bisecting things, I narrowed down the commit which causing things to break to commit 449000102901: "virtio-net: enable multiqueue by default". Reverting this commit on top of next-20161209 fixed the problem.
[1] http://thunk.org/gce-xfstests You can reproduce the problem for building the kernel for Google Compute Engine --- I use a config such as this [2], and then try to boot a kernel on a VM. The way I do this involves booting a test appliance and then kexec'ing into the kernel to be tested[3], using a 2cpu configuration. (GCE machine type: n1-standard-2) [2] https://git.kernel.org/cgit/fs/ext2/xfstests-bld.git/tree/kernel-configs/ext4-x86_64-config-4.9 [3] https://github.com/tytso/xfstests-bld/blob/master/Documentation/gce-xfstests.md You can then take a look at serial console using a command such as "gcloud compute instances get-serial-port-output <instance-name>", and you will get something like this (see attached). The important bit is that the dhclient command is completely failing to be able to get a response from the network, from which I deduce that apparently that either networking send or receive or both seem to be badly affected by the commit in question. Please let me know if there's anything I can do to help you debug this further. Cheers, - Ted Dec 11 23:53:20 xfstests-201612120451 kernel: [ 0.000000] Linux version 4.9.0-rc8-ext4-06387-g03e5cbd (tytso@tytso-ssd) (gcc version 4.9.2 (Debian 4.9.2-10) ) #9 SMP Mon Dec 12 04:50:16 UTC 2016 Dec 11 23:53:20 xfstests-201612120451 kernel: [ 0.000000] Command line: root=/dev/sda1 ro console=ttyS0,38400n8 elevator=noop console=ttyS0 fstestcfg=4k fstestset=-g,quick fstestexc= fstestopt=aex fstesttyp=ext4 fstestapi=1.3 Dec 11 23:53:20 xfstests-201612120451 kernel: [ 0.000000] x86/fpu: Supporting XSAVE feature 0x001: 'x87 floating point registers' Dec 11 23:53:20 xfstests-201612120451 kernel: [ 0.000000] x86/fpu: Supporting XSAVE feature 0x002: 'SSE registers' Dec 11 23:53:20 xfstests-201612120451 kernel: [ 0.000000] x86/fpu: Supporting XSAVE feature 0x004: 'AVX registers' Dec 11 23:53:20 xfstests-201612120451 kernel: [ 0.000000] x86/fpu: xstate_offset[2]: 576, xstate_sizes[2]: 256 Dec 11 23:53:20 xfstests-201612120451 kernel: [ 0.000000] x86/fpu: Enabled xstate features 0x7, context size is 832 bytes, using 'standard' format. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started Load Kernel Modules. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting Apply Kernel Variables... Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Mounting Configuration File System... Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Mounting FUSE Control File System... Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Mounted FUSE Control File System. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Mounted Configuration File System. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started Apply Kernel Variables. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started Create Static Device Nodes in /dev. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting udev Kernel Device Manager... Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started udev Kernel Device Manager. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started udev Coldplug all Devices. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting udev Wait for Complete Device Initialization... Dec 11 23:53:20 xfstests-201612120451 systemd-fsck[1659]: xfstests-root: clean, 56268/655360 files, 357439/2620928 blocks Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started File System Check on Root Device. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting Remount Root and Kernel File Systems... Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started Remount Root and Kernel File Systems. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started Various fixups to make systemd work better on Debian. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting Load/Save Random Seed... Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting Local File Systems (Pre). Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Reached target Local File Systems (Pre). Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started Load/Save Random Seed. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started udev Wait for Complete Device Initialization. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting Activation of LVM2 logical volumes... Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting Copy rules generated while the root was ro... Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Found device /dev/ttyS0. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Found device /dev/ttyS1. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started Copy rules generated while the root was ro. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Found device /dev/ttyS2. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Found device /dev/ttyS3. Dec 11 23:53:20 xfstests-201612120451 systemd-udevd[2568]: could not open moddep file '/lib/modules/4.9.0-rc8-ext4-06387-g03e5cbd/modules.dep.bin' Dec 11 23:53:20 xfstests-201612120451 lvm[2579]: No volume groups found Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started Activation of LVM2 logical volumes. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting Encrypted Volumes. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Reached target Encrypted Volumes. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting Activation of LVM2 logical volumes... Dec 11 23:53:20 xfstests-201612120451 lvm[2625]: No volume groups found Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started Activation of LVM2 logical volumes. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting Monitoring of LVM2 mirrors, snapshots etc. using dmeventd or progress polling... Dec 11 23:53:20 xfstests-201612120451 lvm[2627]: No volume groups found Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started Monitoring of LVM2 mirrors, snapshots etc. using dmeventd or progress polling. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting Local File Systems. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Reached target Local File Systems. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting Remote File Systems. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Reached target Remote File Systems. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting Trigger Flushing of Journal to Persistent Storage... Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting Create Volatile Files and Directories... Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting LSB: Generate ssh host keys if they do not exist... Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting LSB: Raise network interfaces.... Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started Trigger Flushing of Journal to Persistent Storage. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started Create Volatile Files and Directories. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started LSB: Generate ssh host keys if they do not exist. Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Starting Update UTMP about System Boot/Shutdown... Dec 11 23:53:20 xfstests-201612120451 systemd[1]: Started Update UTMP about System Boot/Shutdown. Dec 11 23:53:20 xfstests-201612120451 dhclient: Internet Systems Consortium DHCP Client 4.3.1 Dec 11 23:53:20 xfstests-201612120451 dhclient: Copyright 2004-2014 Internet Systems Consortium. Dec 11 23:53:20 xfstests-201612120451 dhclient: All rights reserved. Dec 11 23:53:20 xfstests-201612120451 dhclient: For info, please visit https://www.isc.org/software/dhcp/ Dec 11 23:53:20 xfstests-201612120451 dhclient: Dec 11 23:53:20 xfstests-201612120451 networking[2633]: Configuring network interfaces...Internet Systems Consortium DHCP Client 4.3.1 Dec 11 23:53:20 xfstests-201612120451 networking[2633]: Copyright 2004-2014 Internet Systems Consortium. Dec 11 23:53:20 xfstests-201612120451 networking[2633]: All rights reserved. Dec 11 23:53:20 xfstests-201612120451 networking[2633]: For info, please visit https://www.isc.org/software/dhcp/ Dec 11 23:53:20 xfstests-201612120451 dhclient: Listening on LPF/eth0/42:01:0a:f0:00:03 Dec 11 23:53:20 xfstests-201612120451 dhclient: Sending on LPF/eth0/42:01:0a:f0:00:03 Dec 11 23:53:20 xfstests-201612120451 dhclient: Sending on Socket/fallback Dec 11 23:53:20 xfstests-201612120451 dhclient: DHCPREQUEST on eth0 to 255.255.255.255 port 67 Dec 11 23:53:20 xfstests-201612120451 networking[2633]: Listening on LPF/eth0/42:01:0a:f0:00:03 Dec 11 23:53:20 xfstests-201612120451 networking[2633]: Sending on LPF/eth0/42:01:0a:f0:00:03 Dec 11 23:53:20 xfstests-201612120451 networking[2633]: Sending on Socket/fallback Dec 11 23:53:20 xfstests-201612120451 networking[2633]: DHCPREQUEST on eth0 to 255.255.255.255 port 67 Dec 11 23:53:20 xfstests-201612120451 dhclient: DHCPREQUEST on eth0 to 255.255.255.255 port 67 Dec 11 23:53:20 xfstests-201612120451 networking[2633]: DHCPREQUEST on eth0 to 255.255.255.255 port 67 Dec 11 23:53:20 xfstests-201612120451 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8 Dec 11 23:53:20 xfstests-201612120451 networking[2633]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8 Dec 11 23:53:20 xfstests-201612120451 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8 Dec 11 23:53:20 xfstests-201612120451 networking[2633]: DHCP[[32m OK [0m] DISCOVER on eth0 to 255.255.255.255 port 67 interval 8 Dec 11 23:53:20 xfstests-201612120451 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 13 Dec 11 23:53:20 xfstests-201612120451 networking[2633]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 13 Dec 11 23:53:20 xfstests-201612120451 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 17 Dec 11 23:53:20 xfstests-201612120451 networking[2633]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 17 Dec 11 23:53:20 xfstests-201612120451 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 15 Dec 11 23:53:20 xfstests-201612120451 networking[2633]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 15 Dec 11 23:53:20 xfstests-201612120451 dhclient: No DHCPOFFERS received. Dec 11 23:53:20 xfstests-201612120451 dhclient: Trying recorded lease 10.240.0.3 Dec 11 23:53:20 xfstests-201612120451 networking[2633]: No DHCPOFFERS received. Dec 11 23:53:20 xfstests-201612120451 networking[2633]: Trying recorded lease 10.240.0.3 Dec 11 23:53:20 xfstests-201612120451 networking[2633]: connect: Network is unreachable Dec 11 23:53:20 xfstests-201612120451 logger: /etc/dhcp/dhclient-exit-hooks returned non-zero exit status 2 Dec 11 23:53:20 xfstests-201612120451 dhclient: bound: renewal in 38598 seconds. Dec 11 23:53:20 xfstests-201612120451 networking[2633]: bound: renewal in 38598 seconds. Dec 11 23:53:20 xfstests-201612120451 networking[2633]: done.
