On 01/18/22 at 10:13pm, Jisheng Zhang wrote: > On Sun, Jan 16, 2022 at 09:38:47PM +0800, Baoquan He wrote: > > Hi Jisheng, > > Hi Baoquan, > > > > > On 12/07/21 at 12:05am, Jisheng Zhang wrote: > > > Replace the conditional compilation using "#ifdef CONFIG_KEXEC_CORE" > > > by a check for "IS_ENABLED(CONFIG_KEXEC_CORE)", to simplify the code > > > and increase compile coverage. > > > > I go through this patchset, You mention the benefits it brings are > > 1) simplity the code; > > 2) increase compile coverage; > > > > For benefit 1), it mainly removes the dummy function in x86, arm and > > arm64, right? > > Another benefit: remove those #ifdef #else #endif usage. Recently, I > fixed a bug due to lots of "#ifdefs": > http://lists.infradead.org/pipermail/linux-riscv/2021-December/010607.html Glad to know the fix. While, sometime the ifdeffery is necessary. I am sorry about the one in riscv and you have fixed, it's truly a bug . But, the increasing compile coverage at below you tried to make, it may cause issue. Please see below my comment. > > > > > For benefit 2), increasing compile coverage, could you tell more how it > > achieves and why it matters? What if people disables CONFIG_KEXEC_CORE in > > purpose? Please forgive my poor compiling knowledge. > > Just my humble opinion, let's compare the code:: > > #ifdef CONFIG_KEXEC_CORE > > code block A; > > #endif > > If KEXEC_CORE is disabled, code block A won't be compiled at all, the > preprocessor will remove code block A; > > If we convert the code to: > > if (IS_ENABLED(CONFIG_KEXEC_CORE)) { > code block A; > } > > Even if KEXEC_CORE is disabled, code block A is still compiled. This is what I am worried about. Before, if CONFIG_KEXEC_CORE is unset, those relevant codes are not compiled in. I can't see what benefit is brought in if compiled in the unneeded code block. Do I miss anything? _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
