|Summary:||/etc/crontab et al has no rmmod -a invocation|
|Product:||[Retired] Red Hat Raw Hide||Reporter:||Chris Siebenmann <cks-rhbugzilla>|
|Component:||modutils||Assignee:||Cristian Gafton <gafton>|
|Status:||CLOSED CURRENTRELEASE||QA Contact:|
|Fixed In Version:||Doc Type:||Bug Fix|
|Doc Text:||Story Points:||---|
|Last Closed:||1999-04-13 16:29:43 UTC||Type:||---|
|oVirt Team:||---||RHEL 7.3 requirements from Atomic Host:|
|Cloudforms Team:||---||Target Upstream Version:|
Description Chris Siebenmann 1999-04-03 10:40:27 UTC
2.2.* kernels require 'rmmod -a' to be run periodically in order to automatically remove autoclean(able) kernel modules. crontabs-1.7-5 doesn't seem to have any such invocation; presumably one should be added (at an interval picked to suit). I'd suggest something like: */10 * * * * root /sbin/rmmod -as
Comment 1 Preston Brown 1999-04-05 20:24:59 UTC
Periodically removing not-needed kernel modules is debatably a good thing. However, it can be a very bad thing. For instance, for sound cards (the most common thing to be periodically in use followed by periods of unuse) unloading the driver causes it to lose current mixer settings, etc. etc. Cristian, opinion?
Comment 2 Chris Siebenmann 1999-04-05 22:25:59 UTC
A RedHat 5.2 system will unload unused kernel modules that are marked as autocleanable (some, eg sound modules and the st module, are not marked autocleanable when loaded). At the moment, a Rawhide-based system won't, because of kerneld being replaced by other things. That's why I suspect that this is a bug.
Comment 3 Preston Brown 1999-04-09 19:06:59 UTC
Cristian are we going to fix this for the release.
Comment 4 Cristian Gafton 1999-04-09 21:54:59 UTC
The kmod is still in its early stages - the kmod will eventually deal with this. For now, suddenly unloading unused modul;es can be a real pain - for example my sound card does an ugly noise every time the sound module is loaded, and I don;t want to hear that every N minutes. Also, some module loading can cause real problems and delays, like probing for a scsi card, etc. So for now we will have to live with it.
Comment 5 Chris Siebenmann 1999-04-10 04:43:59 UTC
I'm not sure this is being understood, from the comments so far, so: - modules can only be removed if they are *both* unused (for a while) *and* marked as autocleanable. - modules loaded explicitly, such as sound and SCSI tape and so on, are generally not marked autocleanable unless one takes specific steps to do so. - in 2.0.* kernels, ie in RedHat 5.0/5.1/5.2, kerneld periodically removes such modules. - in 2.2.* kernels there is no kerneld. In order to duplicate its removal of idle, autocleanable modules one must run an rmmod -a periodically. This has *identical* behavior as kerneld does/did. A number of modules will be marked as autocleanable in a normal configuration: ethernet drivers, PPP and compression methods, all the various modules associated with alternate filesystems such as MS-DOS (or NFS), the loopback driver, etc. Right now, a RedHat 5.0/5.1/5.2/etc machine will unload these modules when they haven't been used for a while and are no longer needed. A Rawhide or Starbuck machine does not; they stick around to clutter up memory. If your RedHat 5.x machine is working fine now, adding 'rmmod -a' to the crontab of an equivalent Starbuck/Rawhide will just make it behave the same. Not adding it has the primary effect of cluttering up memory with currently extraneous modules. Adding the rmmod -a won't remove any modules that would not have been removed under 5.2 et al. If this *really* is what Redhat thinks is the desirable behavior, I'm puzzled, but it's your call. (I have already seen another person report this omission on the Starbuck mailing list, FYI.)
Comment 6 Michael K. Johnson 1999-04-11 21:25:59 UTC
I understand that we are running kerneld regardless of the kernel version, 2.0 or 2.2, so that it will do all the module loading on a 2.0 kernel, and will do the equivalent of rmmod -a on a 2.2 kernel. cks, can you verify that unused modules are in fact not being unloaded on your system?
Comment 7 Chris Siebenmann 1999-04-12 06:24:59 UTC
I've let my system sit for an hour and a half and autocleanable modules haven't unloaded. Two runs of rmmod -a unloaded them all. Kerneld is definetly not started on a 2.2 kernel, as per the code in /etc/rc.d/rc.sysinit; it only tries to start it if there is no /proc/sys/kernel/modprobe. (And kerneld is not running on my Rawhide system.)
Comment 8 Cristian Gafton 1999-04-12 17:01:59 UTC
johnsonm is taking care of this
Comment 9 Michael K. Johnson 1999-04-12 17:18:59 UTC
Sorry, things had changed between the installed system that I was looking at and the current release and I didn't know it. I'll add the rmmod -a invocation. Thanks for finding this.
Comment 10 Michael K. Johnson 1999-04-13 16:29:59 UTC
modutils as of 2.1.121-11 installs an /etc/cron.d/kmod that does all kernel module related stuff; so far, rmmod -a.