On Fri, Sep 2, 2022 at 5:50 PM Ingo Molnar <mingo@xxxxxxxxxx> wrote: > > > * Nathan Chancellor <nathan@xxxxxxxxxx> wrote: > > > On Sun, Mar 27, 2022 at 09:03:14PM +0200, Ingo Molnar wrote: > > > Yeah, good catch! ... > > > > > > I use defconfigs by explicitly adding in the architecture: > > > > > > kepler:~/tip> make ARCH=i386 defconfig > > > > > > kepler:~/tip> kconfig-arch > > > i386 > > > > > > ... so never I noticed this bug. > > > > Ah, good point! > > > > > I fixed this in the latest version (attached). > > > > > > Arguably 'make ARCH=i386 savedefconfig' should preserve this, so that > > > refreshing defconfigs on bi-arch architectures is idempotent, but that's no > > > excuse to regress the existing defconfig behavior. > > > > Hmmm, I thought that it would, but I think the behavior of savedefconfig > > is actually correct with regards to how it handles CONFIG_64BIT in the > > presence of an explicit ARCH value, based on how CONFIG_64BIT is > > defined: > > > > config 64BIT > > bool "64-bit kernel" if "$(ARCH)" = "x86" > > default "$(ARCH)" != "i386" > > help > > Say yes to build a 64-bit kernel - formerly known as x86_64 > > Say no to build a 32-bit kernel - formerly known as i386 > > > > As the default is no when ARCH == i386 and there is no prompt in that > > situation, "# CONFIG_64BIT is not set" gets dropped, as that is the > > default. Using savedefconfig without the ARCH variable would do the > > right thing. > > > > I tried playing around with these Kconfig symbols to see if I could get > > something that would work for savedefconfig with or without ARCH, but I > > could not really come up with anything. I did not try super hard though, > > it might still be possible. > > Unfortunately, even without the ARCH=i386 'make savedefconfig' doesn't seem > to be doing the right thing & is dropping the '# CONFIG_64BIT is not set' > line: Oh, really? Without ARCH=i386, it works correctly for me. masahiro@zoe:~/ref/linux$ make i386_defconfig savedefconfig # # No change to .config # masahiro@zoe:~/ref/linux$ grep CONFIG_64BIT defconfig # CONFIG_64BIT is not set I guess you gave ARCH=i386 somewhere. > kepler:~/tip> make ARCH=i386 defconfig > *** Default configuration is based on 'i386_defconfig' > # > # configuration written to .config > # > kepler:~/tip> make savedefconfig > kepler:~/tip> diff -up arch/x86/configs/i386_defconfig defconfig > --- arch/x86/configs/i386_defconfig 2022-09-02 10:45:43.117430882 +0200 > +++ defconfig 2022-09-02 10:46:56.663864901 +0200 > @@ -282,4 +282,3 @@ CONFIG_PROVIDE_OHCI1394_DMA_INIT=y > CONFIG_EARLY_PRINTK_DBGP=y > CONFIG_DEBUG_BOOT_PARAMS=y > CONFIG_UNWINDER_FRAME_POINTER=y > -# CONFIG_64BIT is not set > kepler:~/tip> > > This is annoying in that every time I modify the i386 defconfig and use > 'make savedefconfig', I have to manually revert that change ... > > This reduces the usability of 'make savedefconfig' quite a bit. > > Maybe Masahiro-san can tell me how I'm doing this wrong? > > Thanks, > > Ingo -- Best Regards Masahiro Yamada
