On 04/13/22 at 07:37am, Eric DeVolder wrote: > > > On 4/12/22 21:41, Baoquan He wrote: > > On 04/11/22 at 08:54am, Eric DeVolder wrote: > > > > > > > > > On 4/11/22 04:20, Baoquan He wrote: > > > > Hi Eric, > > > > > > > > On 04/01/22 at 02:30pm, Eric DeVolder wrote: > > > > ... ... > > > > > > > > > +static void crash_hotplug_handler(unsigned int hp_action, > > > > > + unsigned long a, unsigned long b) > > > > > > > > I am still struggling to consider if these unused parameters should be > > > > kept or removed. Do you foresee or feel on which ARCH they could be used? > > > > > > > > Considering our elfcorehdr updating method, once memory or cpu changed, > > > > we will update elfcorehdr and cpu notes to reflect all existing memory > > > > regions and cpu in the current system. We could end up with having them > > > > but never being used. Then we may finally need to clean them up. > > > > > > > > If you have investigated and foresee or feel they could be used on a > > > > certain architecture, we can keep them for the time being. > > > > > > So 'hp_action' and 'a' are used within the existing patch series. > > > In crash_core.c, there is this bit of code: > > > > > > + kexec_crash_image->offlinecpu = > > > + (hp_action == KEXEC_CRASH_HP_REMOVE_CPU) ? > > > + (unsigned int)a : ~0U; > > > > > > which is referencing both 'hp_action' and using 'a' from the cpu notifier handler. > > > I looked into removing 'a' and setting offlinecpu directly, but I thought > > > it better that offlinecpu be set within the safety of the kexec_mutex. > > > Also, Sourabh Jain's work with PowerPC utilizing this framework directly > > > references hp_action in the arch-specific handler. > > > > > > The cpu and memory notifier handlers set hp_action accordingly. For cpu handler, > > > the 'a' is set with the impacted cpu. For memory handler, 'a' and 'b' form the > > > impacted memory range. I agree it looks like the memory range is currently > > > not useful. > > > > OK, memory handler doesn't need the action, memory regions. While cpu > > handler needs it to exclude the hot plugged cpu. > > > > We could have two ways to acheive this as below. How do you think about > > them? > > > > static void crash_hotplug_handler(unsigned int hp_action, > > unsigned long cpu) > > > > static int crash_memhp_notifier(struct notifier_block *nb, > > unsigned long val, void *v) > > { > > ...... > > switch (val) { > > case MEM_ONLINE: > > crash_hotplug_handler(KEXEC_CRASH_HP_ADD_MEMORY, > > -1UL); > > break; > > > > case MEM_OFFLINE: > > crash_hotplug_handler(KEXEC_CRASH_HP_REMOVE_MEMORY, > > -1UL); > > break; > > } > > return NOTIFY_OK; > > } > > > > static int crash_cpuhp_online(unsigned int cpu) > > { > > crash_hotplug_handler(KEXEC_CRASH_HP_ADD_CPU, cpu); > > return 0; > > } > > > > static int crash_cpuhp_offline(unsigned int cpu) > > { > > crash_hotplug_handler(KEXEC_CRASH_HP_REMOVE_CPU, cpu); > > return 0; > > } > > I'm OK with the above. Shall I post v7 or are you still looking at patches 7 and 8? > Thanks! Just acked patch 8. Patch 7 need be updated too, so will check in v7. > > > > OR, > > > > static void crash_hotplug_handler(unsigned int hp_action, > > int* cpu) > > > > static int crash_cpuhp_online(unsigned int cpu) > > { > > crash_hotplug_handler(KEXEC_CRASH_HP_ADD_CPU, NULL); > > return 0; > > } > > > > static int crash_cpuhp_offline(unsigned int cpu) > > { > > int dead_cpu = cpu; > > crash_hotplug_handler(KEXEC_CRASH_HP_REMOVE_CPU, &cpu); > > return 0; > > } > > > _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec