Messages in this thread | | | Date | Fri, 11 Dec 2015 18:46:02 +0000 | From | Jason Cooper <> | Subject | Re: [PATCH 0/5] ARM: orion5x/dove/mv78xx0 multiplatform |
| |
On Fri, Dec 11, 2015 at 10:27:30AM -0800, Josh Triplett wrote: > On Fri, Dec 11, 2015 at 01:36:01PM +0000, Jason Cooper wrote: > > +Josh > > > > Hey Arnd, Detlef, > > > > On Fri, Dec 11, 2015 at 12:10:55AM +0100, Arnd Bergmann wrote: > > > On Thursday 10 December 2015 23:00:24 Detlef Vollmann wrote: > > > > On 12/10/15 22:29, Arnd Bergmann wrote: > > > > > On Thursday 10 December 2015 22:14:25 Detlef Vollmann wrote: > > > > >> On 12/10/15 21:59, Arnd Bergmann wrote: > > > > > It may also be worth investigating what has made CONFIG_OF so costly, > > > > Probably because too much is done at runtime and too few things can > > > > be fixed at build time. > > > > > > > > > maybe we can reduce this a bit again. > > > > Probably not without turning the wheel backward :-( > > > > > > > > So for the test: yes it works, but I'm unhappy with it. > > > > > > I'm not too happy about adding 80kb to the uncompressed kernel > > > image either. I've spent some more time now trying to find where > > > we added the bloat. It's mainly in drivers, not in arch specific > > > code, a kilobyte here and there eventually adds up, but the largest > > > portion with a little over 50% of the total diff is drivers/of. > > > > Wasn't there an idea kicked around a while ago to create a > > dt2boardfile script/executable*? Then, during kernel configuration, you > > enable it and select which dts file you want. It would disable > > CONFIG_OF, multiplatform, etc. And generate a board_file.c from the dts > > file. > > > > If anything, it might be worth asking the kernel tinification [1], [2] > > folks if they'd be interested in taking this on... > > No objection if you want to add it to the task list on > tiny.wiki.kernel.org (on the more difficult end).
Done.
> I don't know if you could generate a board file, but I do wonder if you > could effectively compile in a parsed description and ditch the parser. > Bonus if you can make the values parsed out of it into compile-time > constants for constant folding.
After a bit of discussion with Arnd on irc, I agree. Going to a board file doesn't really work since the logic is now mostly in the drivers probe functions.
The dts parsing -> compile-time constants is worth looking into.
thx,
Jason.
| |