extra modules loaded

dambla · 08-03-2006, 06:44 AM

i've just installed debian 3.1r2 and have run into a rather weird problem: although /etc/modules only has 3 lines I end up with tones of modules loaded some of which are just useless (vesa, nls_*, shpchp, etc). lsmod output below

Code:

Module                  Size  Used by
isofs                  33976  1 
ipv6                  229892  6 
floppy                 54992  0 
parport_pc             33348  0 
parport                37320  1 parport_pc
pcspkr                  3816  0 
8139cp                 19072  0 
ohci1394               32004  0 
ieee1394              100408  1 ohci1394
emu10k1_gp              3840  0 
gameport                4736  1 emu10k1_gp
tsdev                   7168  0 
mousedev                9996  1 
joydev                  9536  0 
evdev                   9088  0 
usbhid                 28864  0 
shpchp                 87148  0 
pciehp                 83948  0 
pci_hotplug            30640  2 shpchp,pciehp
via_agp                 8832  1 
agpgart                31784  1 via_agp
ehci_hcd               27908  0 
uhci_hcd               29328  0 
usbcore               104164  5 usbhid,ehci_hcd,uhci_hcd
snd_emu10k1            80776  2 
snd_rawmidi            23204  1 snd_emu10k1
snd_pcm_oss            48168  0 
snd_mixer_oss          16640  1 snd_pcm_oss
snd_pcm                85384  3 snd_emu10k1,snd_pcm_oss
snd_timer              23300  1 snd_pcm
snd_seq_device          7944  2 snd_emu10k1,snd_rawmidi
snd_ac97_codec         59268  1 snd_emu10k1
snd_page_alloc         11144  2 snd_emu10k1,snd_pcm
snd_util_mem            4608  1 snd_emu10k1
snd_hwdep               9092  1 snd_emu10k1
snd                    50660  13 snd_emu10k1,snd_rawmidi,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_timer,snd_seq_device,snd_ac97_codec,snd_util_mem,snd_hwdep
soundcore               9824  1 snd
8139too                23936  0 
mii                     4864  2 8139cp,8139too
via_ircc               20368  0 
irda                  167360  1 via_ircc
crc_ccitt               2432  1 irda
nls_iso8859_1           4352  1 
nls_cp437               6016  2 
vfat                   13184  1 
fat                    41792  1 vfat
dm_mod                 51068  0 
capability              4872  0 
commoncap               7168  1 capability
psmouse                17800  0 
ide_cd                 38176  1 
cdrom                  35740  1 ide_cd
genrtc                  9332  0 
ext3                  109544  4 
jbd                    54552  1 ext3
ide_generic             1664  0 
via82cxxx              12956  1 
ide_disk               16768  6 
ide_core              125028  4 ide_cd,ide_generic,via82cxxx,ide_disk
unix                   26036  82 
font                    8576  0 
vesafb                  6688  0 
cfbcopyarea             3840  1 vesafb
cfbimgblt               3200  1 vesafb
cfbfillrect             3712  1 vesafb

i don't understand where these things come from. I checked /etc/modutils/ and there is nothing there as far as I can see that would load extra modules. any ideas?

adz · 08-03-2006, 10:29 AM

Most of those would get loaded automatically by the kernel or other programs/scripts. This is for a few reasons:

1. Some modules are loaded as dependencies. For example, if you loaded your sound driver, snd-emu10k1, you would find that all those other snd-* modules would get automatically loaded as well.

2. Modules are very often loaded "on demand". If you take a look at the contents of /etc/modules.conf then you'll see a lot of lines like:

Code:

alias <some argument> <some other argument>

These lines configure what modules should be loaded when a particular device gets accessed. So then all it takes is for one program or script to access it and the module gets loaded (plus any dependencies). This is most likely how "isofs" got loaded - you accessed the CD/DVD drive.

3. Certain init scripts can explicitly load a module. Usually not a clean solution but it happens.

If there's a particular module you definetly do not want loaded then you can add it to /etc/modprobe.d/blacklist. However, you should be careful doing this since you may need to load that module a some time later. In other words, if everything is running OK then I wouldn't worry about it too much.

dambla · 08-03-2006, 12:57 PM

thanks for the reply, it cleared things up.