Hi Pingfan, On 04/26/19 at 10:34am, Pingfan Liu wrote: The above paragraphs can explain why we do not need "remove/offline", but it does not say the big picture of what this patch is solving. So the patch log still need to add more things. Basically first thing is "What", What is the problem, what happened, especially the user visible errors. and then how we are going to solve it, why we will workaround it instead of fix it in other way. Thanks Dave

On 04/27/19 at 08:57pm, piliu wrote: Not really, the user visible error is kdump kernel hangs after "I'm in purgatory". Then why it happens, the reason is crash happens on the hot added cpu, but kexec udev rule to restart kdump service - when a core is added, is not being triggered Why kdump service need a restart, the paragraph explained, ... about the dt code, and boot_cpuid stuff ... Currently kdump udev rule use add/remove uevent, why not triggered then? explain it as well. Then how and what is proposed to fix it Finally choosed online/offline (offline is not needed), and why. > > > The above paragraphs can explain why we do not need "remove/offline", > > but it does not say the big picture of what this patch is solving. > > > > So the patch log still need to add more things. Basically first thing is > > "What", What is the problem, what happened, especially the user visible > > errors. and then how we are going to solve it, why we will workaround > > > it instead of fix it in other way. > > > >> > >> Workaround it by using a ppc dedicated udev rules, which uses cpu online/offline message. > >> Further more, as for offline message, it is even useless on powerpc, and can be dropped. > >> > >> 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 > >> -- > >> 2.19.1 > >> > > > > Thanks > > Dave > >