On Wed, May 31, 2023 at 5:11 PM <sunying@xxxxxxxxxxxxxx> wrote: > > On Sat, May 20, 2023 at 1:21 PM <masahiroy@xxxxxxxxxx> wrote: > > > > On Thu, May 18, 2023 at 4:13 PM <sunying@xxxxxxxxxxxxxx> wrote: > > > > > > Hi, > > > > > > > > > We found that the Kconfig build system silently changes invalid values in the. config file, > > > which may prevent users from getting their desired kernel, and also make it hard to know > > > which configuration option caused the forced change based on the compilation information. > > > > > > There are similar questions on stack overflow, where people find it difficult to get > > > the complete dependency chain and other information： > > > > > > ex1. How can I disable CONFIG_PM when building Linux kernel for x86_64 - Stack Overflow > > > https://stackoverflow.com/questions/64499221/how-can-i-disable-config-pm-when-building-linux-kernel-for-x86-64/64501647#64501647 > > > > > > ex2. c - kernel symbol enabled but doesn't shows up in .config - Stack Overflow > > > https://stackoverflow.com/questions/24074116/kernel-symbol-enabled-but-doesnt-shows-up-in-config) > > > > > > ex3. makefile - update menuconfig entries without recompiling all the kernel - Stack Overflow > > > https://stackoverflow.com/questions/71075113/update-menuconfig-entries-without-recompiling-all-the-kernel > > > > > > ex4. linux - disabling CONFIG_NET_DMA - Stack Overflow > > > https://stackoverflow.com/questions/30794576/disabling-config-net-dma/30796820#30796820 > > > > > > We plan to optimize the conf_read() function in /scripts/kconfig/confdata.c, > > > and add information for the mismatched configuration options to help users get the desired Linux kernel. > > > Do you think it's necessary? Any suggestions? > > > > > > > > > It may be helpful. > > I do not know if such warnings should be turned on by default, > > or under some verbose mode, though. > > > > > Can we reuse "KBUILD_VERBOSE" switch to print more warning? > By default, a message is added as follows only when invalid values in .config are detected: > "warning: values in .config are forcibly modified to meet the kconfig dependency constraints. > For more information, enable the environment variable 'export KBUILD_VERBOSE=1'." > > In verbose mode, print invalid configuration options one by one, including error causes and current values, > to help users correct them. For example, in the case of ex1. above, we can prompt with the following message: > "file:line: warning: 'CONFIG_PM' reverse select error, due to 'CONFIG_PM_SLEEO' is set to 'y'." > > Do you think this would work? Can we modify it in this way? I prefer a separate option (e.g. "KCONFIG_*") because KBUILD_VERBOSE=1 is a different class of verbosity. And, I'd like to keep it quiet by default (current behavior). > > > > > Best regards, > > > Siyuan Guo > > > Ying Sun > > > > > > > > > > > > -- > > Best Regards > > Masahiro Yamada > > > -- > Best regards, > Siyuan Guo > Ying Sun > </sunying@xxxxxxxxxxxxxx></masahiroy@xxxxxxxxxx> -- Best Regards Masahiro Yamada
