2018-07-27 2:21 GMT+09:00 Christoph Hellwig <hch@xxxxxx>: > On Wed, Jul 25, 2018 at 01:30:24PM +0900, Masahiro Yamada wrote: >> Could you check the difference of CONFIG_PREEMPT_COUNT, please? >> >> >> For alpha, hexagon, um, >> CONFIG_PREEMPT_COUNT was previously never enabled >> because kernel/Kconfig.preempt was not included. >> >> Now, CONFIG_PREEMPT_COUNT can be enabled >> if it is select'ed by someone. >> >> I guess this change will be OK, but >> I'd like you and Randy to double-check it just in case. > > It might be fine, but with this little fix folded in we should be > safer: > > diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt > index cd1655122ec0..1321a4a7a677 100644 > --- a/kernel/Kconfig.preempt > +++ b/kernel/Kconfig.preempt > @@ -57,4 +57,5 @@ config PREEMPT > endchoice > > config PREEMPT_COUNT > - bool > \ No newline at end of file > + depends on !ARCH_NO_PREEMPT > + bool > -- > To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html This will just add a new unmet dependency warning. CONFIG_PREEMPT_COUNT will be still selected. $ make ARCH=alpha allyesconfig HOSTCC scripts/basic/fixdep HOSTCC scripts/kconfig/conf.o YACC scripts/kconfig/zconf.tab.c LEX scripts/kconfig/zconf.lex.c HOSTCC scripts/kconfig/zconf.tab.o HOSTLD scripts/kconfig/conf scripts/kconfig/conf --allyesconfig Kconfig WARNING: unmet direct dependencies detected for PREEMPT_COUNT Depends on [n]: !ARCH_NO_PREEMPT [=y] Selected by [y]: - DEBUG_ATOMIC_SLEEP [=y] && DEBUG_KERNEL [=y] # # configuration written to .config # -- Best Regards Masahiro Yamada -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html