On Fri, Nov 09, 2018 at 09:04:12AM +0100, Ingo Molnar wrote: > BTW., if you are interested in more radical approaches to optimize > lockdep, we could also add a static checker via objtool driven call graph > analysis, and mark those locks terminal that we can prove are terminal. > > This would require the unified call graph of the kernel image and of all > modules to be examined in a final pass, but that's within the principal > scope of objtool. (This 'final pass' could also be done during bootup, at > least in initial versions.) Something like this is needed for objtool LTO support as well. I just dread the build time 'regressions' this will introduce :/ The final link pass is already by far the most expensive part (as measured in wall-time) of building a kernel, adding more work there would really suck :/