As discussed with Dave offline, there is format issue with V2. Please drop it, and I will send out V3 On 04/28/2019 11:41 AM, Pingfan Liu wrote: > On powerpc, after hot add cpu and trigger crash on the hot-added cpu, the kdump > kernel hangs after "I'm in purgatory". > > The current udev rules expects the dtb to be rebuit on cpu add/remove event. But since > powerpc does not follow the standard cpu hot add framework, it only ejects online/offline > event to user space when cpu is hot added/removed, instead of add/remove event. > Pingfan tried fixing that but it didn't please the maintainer as it breaks some > old userspace tools. > > Due to the failure of dtb's rebuilding, KDump kernel fails to get the 'boot_cpuid' and > eventually fails to boot [see early_init_dt_scan_cpus() in arch/powerpc/kernel/prom.c file] > if system crashes on hot-added CPU. > > Work around it by changing udev rules on powerpc to onlne/offline. > > As for offline message, it is even useless on powerpc, and can be dropped. See the explain: > On powerpc, /sys/devices/system/cpu/cpuX nodes are present for all "possible", irrespective > of whether a CPU is hot-added/removed. > crash_notes are already built for all /sys/devices/system/cpu/cpuX nodes and these nodes > are present for all "possible" CPUs (online/offline/could-be-hot-removed/could-be-hot-added) > > Signed-off-by: Pingfan Liu <piliu(a)redhat.com&gt; > --- > 98-kexec-ppc.rules | 15 +++++++++++++++ > kexec-tools.spec | 10 ++++++++-- > 2 files changed, 23 insertions(+), 2 deletions(-) > create mode 100644 98-kexec-ppc.rules > > diff --git a/98-kexec-ppc.rules b/98-kexec-ppc.rules > new file mode 100644 > index 0000000..9d783a0 > --- /dev/null > +++ b/98-kexec-ppc.rules > @@ -0,0 +1,15 @@ > +SUBSYSTEM=="cpu", ACTION=="online", GOTO="kdump_reload" > +SUBSYSTEM=="memory", ACTION=="online", GOTO="kdump_reload" > +SUBSYSTEM=="memory", ACTION=="offline", GOTO="kdump_reload" > + > +GOTO="kdump_reload_end" > + > +LABEL="kdump_reload" > + > +# If kdump is not loaded, calling "kdumpctl reload" will end up > +# doing nothing, but it and systemd-run will always generate > +# extra logs for each call, so trigger the "kdumpctl reload" > +# only if kdump service is active to avoid unnecessary logs > +RUN+="/bin/sh -c '/usr/bin/systemctl is-active kdump.service || exit 0; /usr/bin/systemd-run --quiet /usr/bin/kdumpctl reload'" > + > +LABEL="kdump_reload_end" > diff --git a/kexec-tools.spec b/kexec-tools.spec > index a1e6686..2bc983c 100644 > --- a/kexec-tools.spec > +++ b/kexec-tools.spec > @@ -18,7 +18,8 @@ Source8: kdump.conf > Source9: http://downloads.sourceforge.net/project/makedumpfile/makedumpfile/1.6.5/... > Source10: kexec-kdump-howto.txt > Source12: mkdumprd.8 > -Source14: 98-kexec.rules > +Source13: 98-kexec.rules > +Source14: 98-kexec-ppc.rules > Source15: kdump.conf.5 > Source16: kdump.service > Source18: kdump.sysconfig.s390x > @@ -169,10 +170,15 @@ install -m 644 %{SOURCE25} $RPM_BUILD_ROOT%{_mandir}/man8/kdumpctl.8 > install -m 755 %{SOURCE20} $RPM_BUILD_ROOT%{_prefix}/lib/kdump/kdump-lib.sh > install -m 755 %{SOURCE23} $RPM_BUILD_ROOT%{_prefix}/lib/kdump/kdump-lib-initramfs.sh > %ifnarch s390x > +install -m 755 %{SOURCE28} $RPM_BUILD_ROOT%{_udevrulesdir}/../kdump-udev-throttler > +%endif > +%ifnarch s390x ppc64 ppc64le > # For s390x the ELF header is created in the kdump kernel and therefore kexec > # udev rules are not required > install -m 644 %{SOURCE14} $RPM_BUILD_ROOT%{_udevrulesdir}/98-kexec.rules > -install -m 755 %{SOURCE28} $RPM_BUILD_ROOT%{_udevrulesdir}/../kdump-udev-throttler > +%endif > +%ifarch ppc64 ppc64le > +install -m 644 %{SOURCE14} $RPM_BUILD_ROOT%{_udevrulesdir}/98-kexec-ppc.rules > %endif > install -m 644 %{SOURCE15} $RPM_BUILD_ROOT%{_mandir}/man5/kdump.conf.5 > install -m 644 %{SOURCE16} $RPM_BUILD_ROOT%{_unitdir}/kdump.service >