Messages in this thread | | | Date | Thu, 13 Apr 2006 16:13:30 -0700 | From | Greg KH <> | Subject | Re: [PATCH] Kmod optimization |
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On Thu, Apr 13, 2006 at 09:04:12PM +0200, tyler@agat.net wrote: > On Thu, Apr 13, 2006 at 11:50:14AM -0700, Greg KH wrote: > > On Thu, Apr 13, 2006 at 08:36:17PM +0200, tyler@agat.net wrote: > > > On Thu, Apr 13, 2006 at 11:24:01AM -0700, Greg KH wrote: > > > > On Thu, Apr 13, 2006 at 08:03:45PM +0200, tyler@agat.net wrote: > > > > > Hi, > > > > > > > > > > the request_mod functions try to load automatically a module by running > > > > > a user mode process helper (modprobe). > > > > > > > > > > The user process is launched even if the module is already loaded. I > > > > > think it would be better to test if the module is already loaded. > > > > > > > > Does this cause a problem somehow? request_mod is called _very_ > > > > infrequently from a normal kernel these days, so I really don't think > > > > this is necessary. > > > > > > Yes I agree it _should_ be very infrequently called but it _will_ be very > > > infrequently called just if the user space configuration is done properly. > > > > What do you mean by this? Almost all 2.6 distros use udev today, which > > prevents this code from ever getting called. So odds are, you are > > optimising something that no one will ever use :) > Well perhaps I don't understand the mechanism :) But let's take an > example. > On all kernels (even recent), if the module smbfs is loaded, it's not > handled by udev and request_module could be called. > > Let"s take another example to see to illustrate why I think > it depends on the user configuration : > module A depends on module B > > if we have a script which do "insmod moduleA.ko ; insmod moduleB.ko", > there will be a call to request_module.
No, that script will fail. Try it out :)
The kernel will not call out to try to resolve the symbols, that's up to userspace to handle. Hint, try running 'modprobe moduleA.ko' instead, it will handle the dependancies correctly.
I still don't see where this is really needed...
thanks,
greg k-h - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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