Hi everyone, I'm doing research on whole-system optimization, and I'd like to ask opinions on the next stage of my work.
== background == After a fair amount of blood, sweat and tears, I have (finally) produced a working ARM kernel that is optimized with gcc's link-time-optimization (LTO) feature. Previously, I had completed a system that did syscall detection in object files, and unused syscall elimination in the Linux kernel. In the next stage of my research, I'm planning on combining those two to do kernel optimization and rebuilding, AFTER the distribution image build. There are a number of other techniques I'll be looking at as well, including 1) profiling applications and re-linking with modified linker scripts to increase the locality of init-time functions (and reduce flash access during boot) 2) profiling block-layer accesses to convert portions of applications to XIP using the AXFS filesystem 3) additional automated kernel feature elimination from whole-image static and runtime analysis. Finally (by way of background), I already have tools to automate the process of installing software on the target, rebooting, running programs and collecting results. == questions == First, has anyone already done anything with OE or YP that takes data from a running system, and feeds it back into the build system? Does it make sense to add recipes to YP that wrap my tools, collect the data and re-start the build process? Is this even possible? That is, can bitbake wait for results from a late build stage, invalidate previous results, and cause rebuilds of key components? Or is this stretching things too far? Has anyone built recipes in OE or YP for image deployment, target control, or test execution? The alternative is to put this iteration outside of the build process. That is, to do an initial build, collect results, modify the build inputs, and do a subsequent build (directed from "above" bitbake, rather than from recipes inside the build system). Does anyone have any experience with this? Any ideas on the best approach? I'm not expert enough in YP to know the dangers here. I would, however, very much like to make this work reproducible and automated, which is why I have a high interest in doing this in YP. Thanks, -- Tim ============================= Tim Bird Architecture Group Chair, CE Workgroup of the Linux Foundation Senior Staff Engineer, Sony Network Entertainment ============================= _______________________________________________ yocto mailing list yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/yocto