On 14.09.2014 22:13, Greg KH wrote: > On Sun, Sep 14, 2014 at 10:05:46PM +0400, Kirill Tkhai wrote: >> On 14.09.2014 21:39, Greg KH wrote: >>> On Sun, Sep 14, 2014 at 09:31:58PM +0400, Kirill Tkhai wrote: >>>> On 14.09.2014 19:38, Greg KH wrote: >>>>> On Sun, Sep 14, 2014 at 02:18:13PM +0400, Kirill Tkhai wrote: >>>>>> This series implements a possibility to show the list of built-in drivers >>>>>> to userspace. The names of drivers will be the same as when they are modules. >>>>> >>>>> Have you looked at /sys/modules/ ? Doesn't that show what you want >>>>> here? >>>> >>>> There are only the drivers in "/sys/module" which have parameters. >>>> Drivers without parameters do not appear there. >>> >>> Ah, didn't realize that. Should be easy to fix though, if you really >>> wanted to list the modules. Much better than a random proc file that >>> you have to parse :) >> >> But it looks like one file is better than many new directories. > > Why? It's just an unification with /proc/modules. Why should we do any difference between external and built-in modules? It's the same, it's similar, it's better to parse when they can be shown similar. > >> Furthermore some utils already may consider /sys/module directory as >> a directory where all drivers have parameters. Is it good if we add >> new ones of different type there? > > What would break if you add new directories there with no parameters? I do not know no one, but it does not mean they do not exist. I just do not want to break anything which already exists. >>>>>> So, if your system has "loop" driver then it appears either in /proc/modules >>>>>> or in /proc/built-in and userspace will be able to know about this. >>>>>> >>>>>> Now this is impossible. The only way to get kernel configuration is >>>>>> /proc/config.gz, but CONFIG_* names can change from time to time. Module >>>>>> names are more or less standardized. >>>>> >>>>> Module names aren't "standardized", we change them at times when needed, >>>>> just like CONFIG_ names. >>>>> >>>>> What is your end goal here? As you say, config.gz is the real kernel >>>>> configuration, just having a list of modules built in isn't going to >>>>> help much in getting a working kernel config without it. >>>> >>>> It looks like userspace applications oriented on modules names rather >>>> than on CONFIG_XXX parameters. /proc/config.gz is optional and userspace >>>> applications can't base on it. >>>> >>>> For example, when I compile "loop" module built-in and "loop" is in >>>> /etc/modules, init script warns about this module is not present and >>>> can't be autoloaded. The script does not store CONFIG_XXX <-> module_xxx >>>> conformity. And nobody stores it. >>>> >>>> When iptables wants extra functionality, it requests a module. Etc. >>>> >>>> Nobody is oriented on CONFIG_XXX parameters. It would be simple for >>>> userspace to add a support of /proc/built-in analysing. It's very >>>> similar to /proc/modules. >>> >>> Shouldn't userspace focus on the functionality a module provides, not >>> the module name itself? Can't a test for the loop "module" just test to >>> see if the loop control device is present? Same for iptables (there's >>> modprobe rules for iptable modules I think...) >>> >>> In other words, don't focus on the module names, focus on the userspace >>> function a module provides, there should always be a way to check that >>> at run time (if not, then the module doesn't actually do much...) >> >> Hm, I'm not sure that anybody stores CONFIG_XXX <-> module_xxx >> conformity. Everybody bases on module name. If application is seeing >> CONFIG_XXX=m, but the functionality, which it want's, is not available, >> what it has to do? How should it convert CONFIG_XXX to module name? > > Why would an application ever care about CONFIG_XXX at runtime? > >> So, many applications want module name instead of CONFIG_XXX, I believe. > > No, they want the functionality that a module provides, not the module > name, or some random configuation option. > > It seems like you are trying to solve a problem that isn't there. What > program is broken right now that this new proc file (or sysfs directory) > would fix? The initial reason was I'm building custom kernels for more than 10 years (not so long, I agree), and every boot I see a big list of modules from distribution /etc/module, which can't be autoloaded. I prefer to build drivers in kernel. I tried to find is there a way for userspace to understand that a module are present, but there is no a way. So this is a reason. -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
