On 10/17/21 11:12 AM, Julia Lawall wrote:
Hello, If I do the following: git clean -dfx cp saved_config .config make olddefconfig && make && make modules_install && make install Should I always end up with the same kernel, regardless of the kernel that is currently running on the machine? I see a large performance difference between Linux 5.10 and all versions afterwards for a particular benchmark. I am unable to bisect the problem eg between 5.10 and 5.11, because as soon as I come to a kernel that gives the bad performance, all of the kernels that I generate subsequently in the bisecting process (using the above commands) also have the bad performance. It could of course be that I have completely misinterpreted the problem, and it has nothing to do with the kernel. But I have tested the program a lot when only working on variants of Linux 5.9. I only start to have problems when I use versions >= 5.11.
Hi, My "guess" is that this has something to do with the build reusing some current file(s) that need to be rebuilt. I.e., adding a "make clean" or "make proper" might be needed. I say this only because sometimes I cannot even reproduce a build that has errors or warnings unless I prefix it with make clean or mrproper. (i.e., nothing to do with booting and running the new kernel) Even though the .config file has changed and I do "make olddefconfig", the same build errors do not show up unless I do the clean or mrproper step also. -- ~Randy
