The Linux kernel series "crash: Kernel handling of CPU and memory hot un/plug" recently landed in mainline. To take advantage of the performance benefits of that series, 98-kexec.rules needs an update to optimize the handling of CPU and memory hotplug changes.

It is safe to deploy these rule updates now, ahead of distros/kernels enabling the feature, since the crash_hotplug sysfs nodes would not be present and thus the newly introduced rules in 98-kexec would act as a nop-op and fall thru for legacy behavior. But when distros/kernels enable the feature, then 98-kexec rules is ready and can properly take advantage.

Link: https://lore.kernel.org/lkml/20230814214446.6659-1-eric.devolder@oracle.com/ Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... Signed-off-by: Eric DeVolder eric.devolder@oracle.com --- 98-kexec.rules | 4 ++++ 98-kexec.rules.ppc64 | 4 ++++ 2 files changed, 8 insertions(+)

diff --git a/98-kexec.rules b/98-kexec.rules index b73b701..52b2ee8 100644 --- a/98-kexec.rules +++ b/98-kexec.rules @@ -1,3 +1,7 @@ +# The kernel updates the crash elfcorehdr for CPU and memory changes +SUBSYSTEM=="cpu", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end" +SUBSYSTEM=="memory", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end" + SUBSYSTEM=="cpu", ACTION=="add", GOTO="kdump_reload" SUBSYSTEM=="cpu", ACTION=="remove", GOTO="kdump_reload" SUBSYSTEM=="memory", ACTION=="online", GOTO="kdump_reload" diff --git a/98-kexec.rules.ppc64 b/98-kexec.rules.ppc64 index a1c00a9..94c8b5d 100644 --- a/98-kexec.rules.ppc64 +++ b/98-kexec.rules.ppc64 @@ -1,3 +1,7 @@ +# The kernel updates the crash elfcorehdr for CPU and memory changes +SUBSYSTEM=="cpu", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end" +SUBSYSTEM=="memory", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end" + SUBSYSTEM=="cpu", ACTION=="online", GOTO="kdump_reload_cpu" SUBSYSTEM=="memory", ACTION=="online", GOTO="kdump_reload_mem" SUBSYSTEM=="memory", ACTION=="offline", GOTO="kdump_reload_mem"