Re: The necessity of running depmod at boot time
Joey Hess wrote: Marco d'Itri wrote: If we can agree that it's not needed anymore (i.e. mandate by policy that packages need to run depmod on their own) then I will be happy to remove it from the m-i-t init script. A while back Debian would only run depmod on boot if it had not been run before since the last kernel upgrade. Could you refresh my memory about why that optimisation was dropped? I don't believe that it was. Looking at the code in sid, I see a call to 'depmod --quick'. That is supposed to compare timestamps on files to determine if depmod needs to be run in full. Presumably then, you should get at most one boot that runs depmod after a kernel change, but it sounds like Margarita is seeing a full run of depmod every time. We saw that in Linspire at one point, but I had thought it was something we had introduced, not inherited. There were two entities that were making sure things were up-to-date, and the second one was modifying files on every boot after depmod had gone around and regenerated everything, creating a vicious circle. If that is happening, then you may find that the 'depmod --quick' is fine once that is fixed.
Re: The necessity of running depmod at boot time
Marco d'Itri wrote: I think because depmod --quick is supposed to be about as fast as find. YM as fast as test -nt? Doesn't seem to be on a dry cache. -- see shy jo signature.asc Description: Digital signature
Re: The necessity of running depmod at boot time
On May 19, Joey Hess [EMAIL PROTECTED] wrote: Marco d'Itri wrote: I think because depmod --quick is supposed to be about as fast as find. YM as fast as test -nt? Doesn't seem to be on a dry cache. No, I really meant as fast as find. Which other test do you suggest? -- ciao, Marco signature.asc Description: Digital signature
Re: The necessity of running depmod at boot time
On Thu, May 18, 2006 at 07:21:33PM -0300, Margarita Manterola wrote: Continuing on the goal of optimizing boot time, quite a number of seconds (specially in old machines) can be saved by not running depmod at boot time. Currently it is run by these packages' postinst: Wouldn't it be a good idea to list the packages running depmod in their _init_ scripts? Currently, you're listing packages which seem to do the right thing, not the wrong thing. /* Steinar */ -- Homepage: http://www.sesse.net/ -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: The necessity of running depmod at boot time
On May 19, Margarita Manterola [EMAIL PROTECTED] wrote: Continuing on the goal of optimizing boot time, quite a number of seconds (specially in old machines) can be saved by not running depmod at boot time. If we can agree that it's not needed anymore (i.e. mandate by policy that packages need to run depmod on their own) then I will be happy to remove it from the m-i-t init script. -- ciao, Marco signature.asc Description: Digital signature
Re: The necessity of running depmod at boot time
On Thu, May 18, 2006 at 07:21:33PM -0300, Margarita Manterola [EMAIL PROTECTED] wrote: Continuing on the goal of optimizing boot time, quite a number of seconds (specially in old machines) can be saved by not running depmod at boot time. (...) It looks like it's quite safe to stop running depmod during boot time, since both new kernels and new modules run it at install time. If there are modules that don't run depmod on installation, they should do it. Opinions about this are welcome. Last time I took a look to that boot depmod, it was supposed to be launched by the script only if necessary, but for some reason, just was launched at every single boot. Never figured out why, and forgot to file a bug. Mike -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: The necessity of running depmod at boot time
Marco d'Itri wrote: If we can agree that it's not needed anymore (i.e. mandate by policy that packages need to run depmod on their own) then I will be happy to remove it from the m-i-t init script. A while back Debian would only run depmod on boot if it had not been run before since the last kernel upgrade. Could you refresh my memory about why that optimisation was dropped? -- see shy jo signature.asc Description: Digital signature
Re: The necessity of running depmod at boot time
On Thu, May 18, 2006 at 07:21:33PM -0300, Margarita Manterola wrote: Continuing on the goal of optimizing boot time, quite a number of seconds (specially in old machines) can be saved by not running depmod at boot time. Currently it is run by these packages' postinst: * [long list] It looks like it's quite safe to stop running depmod during boot time, since both new kernels and new modules run it at install time. If there are modules that don't run depmod on installation, they should do it. I think one of the issues here is that it depends on what kernel you currently use, and iirc there can be a situation where one does not want to run depmod at installation time, or when that might give wrong results. What I think would be best is to have every packages that now requires running depmod at boot time, will touch a file in /lib/modules/kernel-api when it has changed the kernel (or modules) significantly so that it is needed to be run, and at boot time only run depmod if that touched file exists (and have the file removed after having run depmod succesfully). This way, depmod at boot is only run after changes in kernel or modules once for each given kernel API that's booted. If the package code in each package for this (for the bit to conditionally run depmod at installation time too) is not trivial, it might be worth having a bit about this in some dh_* script, so that the code in question is only written once. I'm not sure here though, I don't think it's needed as the majority of the code can be in the package providing depmod. --Jeroen -- Jeroen van Wolffelaar [EMAIL PROTECTED] (also for Jabber MSN; ICQ: 33944357) http://Jeroen.A-Eskwadraat.nl -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: The necessity of running depmod at boot time
Margarita Manterola wrote: Currently it is run by these packages' postinst: * kernel/linux-image-* This takes care to run depmod -F system.map version, which should make the depmod work even though that kernel isn't running yet. * pwc-modules-* * ndiswrapper-modules-* * linux-wlan-ng-modules-* * spca5xx-modules-* * kernel-pcmcia-modules-* * hostap-modules-* * alsa-modules-* * pwc-modules-* * linux-wlan-ng-modules-* * ieee80211softmac-modules-* * misdn-modules-* * unionfs-modules-* I've checked a few of these as well as dh_installmodules and none I've checked bother with -F or the kernel version, so installing a new version of the kernel, and then third party modules that use it, then rebooting into the new kernel, will not make the modules available if the depmod on boot is not run at least the first time booting a new kernel. Of course, all of these could be fixed to run depmod correctly, although adding that to dh_installmodules will require some way to determine the kernel version the modules are built for. -- see shy jo signature.asc Description: Digital signature
Re: The necessity of running depmod at boot time
Jeroen van Wolffelaar wrote: I think one of the issues here is that it depends on what kernel you currently use, and iirc there can be a situation where one does not want to run depmod at installation time, or when that might give wrong results. FWIW, d-i currently runs depmod at image build time, when a different kernel is generally running than the one on the image being built, and we've not had any problems with it since at least the sarge release. IIRC there were some bugs with it a few years ago. -- see shy jo signature.asc Description: Digital signature
Re: The necessity of running depmod at boot time
On May 19, Joey Hess [EMAIL PROTECTED] wrote: A while back Debian would only run depmod on boot if it had not been run before since the last kernel upgrade. Could you refresh my memory about why that optimisation was dropped? I think because depmod --quick is supposed to be about as fast as find. A second reason for which I would like to remove the depmod call is that -w does not actually work to test if / is mounted read only, so to fix the script I would need to touch /lib/modules at every boot (#358239). -- ciao, Marco signature.asc Description: Digital signature
Re: The necessity of running depmod at boot time
Jeroen van Wolffelaar [EMAIL PROTECTED] writes: I think one of the issues here is that it depends on what kernel you currently use, and iirc there can be a situation where one does not want to run depmod at installation time, or when that might give wrong results. That used to be the case but for a while now that has been fixed. It is just a matter of having all packages call depmod properly. (see other mails). MfG Goswin -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
