Hi Srivatsa, just a small personal comment below since I'm not the 4.4 maintainer :-) On Fri, Jul 13, 2018 at 02:49:14PM -0700, Srivatsa S. Bhat wrote: > You'll notice that the initial few patches in this series include > cleanups etc., that are non-critical to IBPB/IBRS/SSBD. Most of these > patches are aimed at getting the cpufeature.h vs cpufeatures.h split > into 4.4, since a lot of the subsequent patches update these headers. > On my first attempt to backport these patches to 4.4.y, I had actually > tried to do all the updates on the cpufeature.h file itself, but it > started getting very cumbersome, so I resorted to backporting the > cpufeature.h vs cpufeatures.h split and their dependencies as well. When I used to maintain 2.6.32, initially I tried to backport the minimal amount of changes. It quickly resulted in certain files (mostly includes) diverging a lot from more recent versions, making it a real pain to later backport other fixes. Worse, sometimes I would even not be 100% confident in my backports (eg: macros being declared very differently or at multiple places which I could easily miss). For 3.10, I stopped doing that and instead preferred to pick a bit more "noise" to prepare and adapt the files to be patched so that overall the code looked more similar to more recent versions. I found that not only it helped with backports, but it also reduced the amount of breakage introduced for later backports, and it helped with reviews, since what matters is not that the old kernel is correct but that the recent one is, and if the code is the same then the old one is correct. Thus based on my experiences with two different methods I guess that I had the best approach here. > I would appreciate if you could kindly consider these patches for > review and inclusion in a future 4.4.y release. However here I notice that your patches were not CCed to their respective authors nor to the list of participants, I predict that Greg will ask you for this as they're almost the only ones understanding their own tricks ;-) Cheers, Willy
