Eric DeVolder <eric.devol...@oracle.com> writes: > On 4/21/22 06:34, Michael Ellerman wrote: >> Sourabh Jain <sourabhj...@linux.ibm.com> writes: >>> The option CRASH_HOTPLUG enables, in kernel update to kexec segments on >>> hotplug events. >>> >>> All the updates needed on the capture kernel load path in the kernel for >>> both kexec_load and kexec_file_load system will be kept under this config. >>> >>> Signed-off-by: Sourabh Jain <sourabhj...@linux.ibm.com> >>> Reviewed-by: Eric DeVolder <eric.devol...@oracle.com> >>> --- >>> arch/powerpc/Kconfig | 11 +++++++++++ >>> 1 file changed, 11 insertions(+) >>> >>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig >>> index b779603978e1..777db33f75b5 100644 >>> --- a/arch/powerpc/Kconfig >>> +++ b/arch/powerpc/Kconfig >>> @@ -623,6 +623,17 @@ config FA_DUMP >>> If unsure, say "y". Only special kernels like petitboot may >>> need to say "N" here. >>> >>> +config CRASH_HOTPLUG >>> + bool "kernel updates of crash kexec segments" >>> + depends on CRASH_DUMP && (HOTPLUG_CPU) && KEXEC_FILE >>> + help >>> + An efficient way to keep the capture kernel up-to-date with CPU >>> + hotplug events. On CPU hotplug event the kexec segments of capture >>> + kernel becomes stale and need to be updated with latest CPU data. >>> + In this method the kernel performs minimal update to only relevant >>> + kexec segments on CPU hotplug event, instead of triggering full >>> + capture kernel reload from userspace using udev rule. >> >> Why would a user ever want to turn this off? >> >> Seems to me we should just make it always behave this way, and not have >> a CONFIG option at all. > > Sourabh, > > Borislav Petkov also requested I remove the config option, which will be the > case in upcoming v8. > > Where I was using CONFIG_CRASH_HOTPLUG, I've replaced it with the > CONFIG_HOTPLUG_CPU || CONFIG_MEMORY_HOTPLUG.
If you're having to spell "CONFIG_HOTPLUG_CPU || CONFIG_MEMORY_HOTPLUG" in many places then you can still add CONFIG_CRASH_HOTPLUG to represent the sum of all the dependencies, just don't make it user-selectable. cheers
