fedora 14 kernel performance with ip forwarding workload
by Jesse Brandeburg
The other day I was running the stock fedora kernel on my ip
forwarding setup, to see what the performance was, and the performance
wasn't very good.
system is S5520HC dual socket 2.93GHz Xeon 5570 (Nehalem) with 3 quad
port 82580 adapters (12 ports). Traffic is bidirectional 64 byte
packets being forwarded and received on each port, basically port to
port routing. I am only using 12 flows currently.
The driver is igb, and I am using an affinity script that lines up
each pair of ports that are forwarding traffic into optimal
configurations for cache locality. I am also disabling
remote_node_defrag_ratio to stop cross node traffic.
With the fedora default kernel from F14 it appears that
CONFIG_NETFILTER=y means that I cannot unload all of netfilter even if
I stop iptables service.
perf showed netfilter being prominent, and removing it gives me much
higher throughput. Is there a reason CONFIG_NETFILTER=y ? Isn't it a
good thing to be able to disable netfilter if you want to?
Jesse
8 years, 10 months
kernel.spec kernel-install integration
by Harald Hoyer
Hi Josh,
as mentioned on IRC, here is the patch for the rawhide kernel.spec.
This patch is part of an upstream coordination, intended to unify the various
ways distributions handle:
- installation of kernels in the system
- create the matching initrds; hooking up the various implementations of
initramfs generators into the kernel package installation process
- optionally/automatically create bootable rescue images to be able to recover
from failures:
https://fedoraproject.org/wiki/Features/DracutHostOnly
All the above functionality is provided by the “kernel-install” tool:
http://www.freedesktop.org/software/systemd/man/kernel-install.html
It features:
- flexible hookup/plugin directories to manage kernel installation and
uninstallation. initrd, bootloader, rescue image management, all plug into
that facility.
- strict separation of distribution-supplied logic and local customization
logic; system administrators are able to overwrite and replace/extend any part
of the default logic if needed
- hide distribution-specific logic behind a standardized command line interface
- unify the custom kernel installation from the source tree with the usual
kernel package installation; like the current /sbin/installkernel
10 years, 11 months
Issue with macvtap:bridge (frozen host)
by Reartes Guillermo
On a F19a host, i have a F19a guest.
Since it looks to me like a kernel issue, the component is currently set as
kernel.
I recently was able to get the full call trace output via a serial port.
*Bug 954181* <https://bugzilla.redhat.com/show_bug.cgi?id=954181> - BUG:
unable to handle kernel paging request at ffff880310d8500b (FROZEN SYSTEM
when scrolling text using ssh on a guest via a macvtap:bridge virtio device)
Thanks in advance.
10 years, 12 months
kernel.spec kernel-install integration
by Harald Hoyer
Ok... subscribed to the list, and resending, because the list moderation seems
to have eaten the attachment.
>
This patch is part of an upstream coordination, intended to unify the various
ways distributions handle:
- installation of kernels in the system
- create the matching initrds; hooking up the various implementations of
initramfs generators into the kernel package installation process
- optionally/automatically create bootable rescue images to be able to recover
from failures:
https://fedoraproject.org/wiki/Features/DracutHostOnly
All the above functionality is provided by the “kernel-install” tool:
http://www.freedesktop.org/software/systemd/man/kernel-install.html
It features:
- flexible hookup/plugin directories to manage kernel installation and
uninstallation. initrd, bootloader, rescue image management, all plug into
that facility.
- strict separation of distribution-supplied logic and local customization
logic; system administrators are able to overwrite and replace/extend any part
of the default logic if needed
- hide distribution-specific logic behind a standardized command line interface
- unify the custom kernel installation from the source tree with the usual
kernel package installation; like the current /sbin/installkernel
11 years
Weirdness with F-18 kernel release number
by Hans de Goede
Hi,
Something is wrong with how the release number for the F-18 kernel
package is getting bumped, luckily the actual version is being
increased most of the time too, not making it matter much, but
still this is clearly wrong:
[hans@shalem ~]$ rpm -q kernel
kernel-3.8.3-203.fc18.x86_64
kernel-3.8.4-202.fc18.x86_64
kernel-3.8.5-201.fc18.x86_64
Notice how as the kernel versions get newer the release gets
older ...
Regards,
Hans
11 years
