# ksoftirqd

## allanroi

elo guys...

Is there anyone familiar with ksoftirqd? This is eating lots of my machine's cpu resources....

comments and suggestions please......

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## Sleipnir

SoftIRQs are a bottom-half mechanism for the kernel. ksoftirqd is the kernel daemon that executes

the SoftIRQ requests. Long speach short. You need that thing! Everything allright. I think mostly

the network subsystem uses softIRQs...

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## allanroi

thanks Sleipnir....

is there anything i need to compile in kernel to minimize it or to fine tune the performance?

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## Sleipnir

Uhmmmm no I think you do not have to tune this thing. It should be fast from the beginning.  :Wink: 

If have no load (i.e. on ethernet) you should maybe have a look on the linux kernel mailing list

and/or report this to the kernel developers....

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## jeanluca

I've the same problem!  It started after I upgraded my system. The good news is is that it not always happens, but when it happens, I cannot stop it, I tried to kill it (it uses 99% of the cpu) 

So what is the cure ? How to solve this problem ?

Thanks in advance

Luca

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## bollucks

That would be a bug. ksoftirqd should never sit there using 99% cpu on an otherwise idle machine. Provided you have a _vanilla_ kernel without binary drivers and are getting this problem, report it to linux kernel mailing list. Oh and please don't try and kill off parts of the kernel - kill -9 on kernel threads aint a great idea  :Razz: 

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## mariux2

I have the same problem. Really anoying since this is a speedstep pc, so now my cpu is running at 1.7Ghz full load instead of 600Mhz no load.

So my system is a Laptop. Centrino 1.7Ghz, Ati Mobility 9700, aopen 1557 barebone and ipw2200. (anyone else have the same?)

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## kortec

Yeah, same deal here. T42, occational 99% usages of my CPU by ksoftirqd for no apparent reason. Can be stopped by /etc/init.d/net.eth1 restart. Here's emerge --info, just for the record books:

```

Gentoo Base System version 1.6.13

Portage 2.0.51.22-r3 (default-linux/x86/2005.0, gcc-3.3.6, glibc-2.3.5-r2, 2.6.14-gentoo-r2 i686)

=================================================================

System uname: 2.6.14-gentoo-r2 i686 Intel(R) Pentium(R) M processor 1.80GHz

ccache version 2.3 [enabled]

dev-lang/python:     2.3.5-r2, 2.4.2

sys-apps/sandbox:    1.2.12

sys-devel/autoconf:  2.13, 2.59-r6

sys-devel/automake:  1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r1

sys-devel/binutils:  2.16.1

sys-devel/libtool:   1.5.20

virtual/os-headers:  2.6.11-r2

ACCEPT_KEYWORDS="x86"

AUTOCLEAN="yes"

CBUILD="i686-pc-linux-gnu"

CFLAGS="-O3 -march=i686 -pipe -fomit-frame-pointer"

CHOST="i686-pc-linux-gnu"

CONFIG_PROTECT="/etc /usr/kde/2/share/config /usr/kde/3/share/config /usr/lib/X11/xkb /usr/share/config /usr/share/texmf/dvipdfm/config/ /usr/share/texmf/dvips/config/ /usr/share/texmf/tex/generic/config/ /usr/share/texmf/tex/platex/config/ /usr/share/texmf/xdvi/ /var/qmail/control"

CONFIG_PROTECT_MASK="/etc/gconf /etc/terminfo /etc/env.d"

CXXFLAGS="-O3 -march=i686 -pipe -fomit-frame-pointer"

DISTDIR="/usr/portage/distfiles"

FEATURES="autoconfig ccache distlocks sandbox sfperms strict"

GENTOO_MIRRORS="http://mirror.datapipe.net/gentoo"

MAKEOPTS="-j2"

PKGDIR="/usr/portage/packages"

PORTAGE_TMPDIR="/var/tmp"

PORTDIR="/usr/portage"

SYNC="rsync://rsync.us.gentoo.org/gentoo-portage"

USE="X acpi alsa audiofile avi bash-completion berkdb bitmap-fonts bzip2 cdparanoia cdr crypt cups divx4linux dvd eds emacs emboss encode esd exif expat fam flac foomaticdb fortran gdbm gif glut gpg gpm gstreamer gtk gtk2 idn imagemagick imlib ipv6 java jpeg lcms ldap libg++ libwww mad mhash mikmod mng motif mp3 mpeg ncurses nls ogg oggvorbis opengl oss pam pcre pdflib perl pic png python quicktime readline ruby sdl spell ssl tcpd tetex tiff truetype truetype-fonts type1-fonts udev usb vorbis wifi win32codecs x86 xine xml2 xmms xv xvid zlib userland_GNU kernel_linux elibc_glibc"

Unset:  ASFLAGS, CTARGET, LANG, LC_ALL, LDFLAGS, LINGUAS, PORTDIR_OVERLAY

```

I am using the external ipw2200 drivers and ATI drivers in addition to the gentoo-sources. This problem, oddly enough, predates ATI. I haven't yet seen a pattern, but I thought I'd post and get some more data points up there. Will update if I suddently become a Kernel hacker.

Oh, and I have worked through much of the powermanagement guide, so I have such nice things as cpufreqd running. Can post process list if anyone's interested, but I thought that might be important.

EDIT:

Found this thread over in the kernel mailing list archives; looks pretty old but at least known. Nothing staggeringly useful, though. 

http://www.ussg.iu.edu/hypermail/linux/kernel/0407.3/0089.html

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## ihtruelsen

I have the same problem, but it really only rears its head when I run bittorrent. At that point, ksoftirqd takes all the cpu and my interenet connection is active, but pretty much useless. 

I am running a centrino machine 1.5 G with ipw2200.

When I try azureus with a torrent in gentoo my cpu maxes out and I get about 5 KB/s down, but I take it to windows xp on the same machine, still with azureus and the centrino wireless and I get 200 KB/s down. And the cpu is not spiked.

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## luca

Hi All

I've A centrino 1.7GHz (with ipw2200) and I have this problem when I start mozilla, so I switched to firefox!!

Cheers

Luca

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## xion

Got the same issue here. "ksoftirqd" is eating almost 100% of my cpu. This happens under heavy network traffic using the ipw2200 wlan-driver from portage. I plugged an ethernet-cable to my notebook and let the traffic being routed over wire. This revealed that it must be the wlan-driver, because ksoftirqd has been really quiet ever since with less than 1 or 2 percent of cpu usage. I used "Azuerus" - also the latest ebuild from portage - to generate the traffic. Looks like the ipw2200-driver is generating some kind of software interrupt-flood which the kernel cannot handle in due time.

Amendment: Removing and reinserting the ipw2200 kernel module really seems to solve this problem (for a certain time of course). Nevertheless, it is still annoying.

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## crouchingturbo

Hate to bump an old thread like this, but I have the *exact* same problem.  IPW2200 driver, ksoftirqd eats up my CPU, internet stops working.  rmmod ipw2200 fixes the problem.  It comes up once every couple days.  Kernel is 2.6.15-r1 (gentoo-sources).

Question: What is the relationship between the ipw2200 driver in the kernel and the ipw2200 package from sourceforge (also in portage)?  Should I be using the sourceforge project instead of the in-kernel driver?

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## xion

I didn't even know that gentoo-sources are already equipped with the ipw2200 driver so I  always installed the ebuild and I haven't encountered the problem for two months so far.

I am using:

```

emerge -pv ipw2200 ; uname -r

These are the packages that would be merged, in order:

Calculating dependencies... done!

[ebuild   R   ] net-wireless/ipw2200-1.1.2-r1  USE="-debug" 132 kB

Total size of downloads: 132 kB

2.6.16-gentoo-r7

```

It seems to be solved. Maybe it helps.

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