Messages in this thread | | | Date | Fri, 2 Aug 2013 16:11:03 +0800 | From | Greg KH <> | Subject | Re: [Ksummit-2013-discuss] [ATTEND] [ARM ATTEND] kernel data bloat and how to avoid it |
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On Fri, Aug 02, 2013 at 12:53:53AM -0700, Tony Lindgren wrote: > * Greg KH <greg@kroah.com> [130731 05:39]: > > On Wed, Jul 31, 2013 at 12:38:03AM -0700, Tony Lindgren wrote: > > > Hi all, > > > > > > Probably the biggest kernel data bloat issue is in the ARM land, but > > > it also seems that it's becoming a Linux generic issue too, so I > > > guess it could be discussed in either context. > > > > Why is it specific to ARM? What is so unique to ARM that causes it to > > "bloat"? > > I think it has so far showed up on ARM because of no discoverable busses, > but chances are it will be more of a generic problem. > > > And what exactly do you mean by "bloat"? > > Stuffing data to kernel that should not be in the kernel at all. Or > if the data is needed by kernel, there should be only one set of the > data defined rather than multiple copies of the data built into the > kernel for each SoC or driver variant. > > > > Basically the data bloat issue is there for the arch code and drivers > > > and may not show up initially until things have headed the wrong way for > > > too long. > > > > What do you mean by this? You seem to be very vague here. > > People are unnecessarily defining registers in kernel for similar devices > over and over again for each new SoC at the arch level and now more and > more at the driver level. > > One example of that are device tree based drivers that don't describe > the actual hardware, but instead have a binding that points to an index > of defined registers in the driver.
Ok, and exactly how much "larger" does something like this cost as a real number, and as a percentage of the size of the kernel?
thanks,
greg k-h
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