On 8/4/25 15:18, David Hildenbrand wrote: > On 04.08.25 13:06, Eugen Hristev wrote: >> >> >> On 8/4/25 13:54, Michal Hocko wrote: >>> On Wed 30-07-25 16:04:28, David Hildenbrand wrote: >>>> On 30.07.25 15:57, Eugen Hristev wrote: >>> [...] >>>>> Yes, registering after is also an option. Initially this is how I >>>>> designed the kmemdump API, I also had in mind to add a flag, but, after >>>>> discussing with Thomas Gleixner, he came up with the macro wrapper idea >>>>> here: >>>>> https://lore.kernel.org/lkml/87ikkzpcup.ffs@tglx/ >>>>> Do you think we can continue that discussion , or maybe start it here ? >>>> >>>> Yeah, I don't like that, but I can see how we ended up here. >>>> >>>> I also don't quite like the idea that we must encode here what to include in >>>> a dump and what not ... >>>> >>>> For the vmcore we construct it at runtime in crash_save_vmcoreinfo_init(), >>>> where we e.g., have >>>> >>>> VMCOREINFO_STRUCT_SIZE(pglist_data); >>>> >>>> Could we similar have some place where we construct what to dump similarly, >>>> just not using the current values, but the memory ranges? >>> >>> All those symbols are part of kallsyms, right? Can we just use kallsyms >>> infrastructure and a list of symbols to get what we need from there? >>> >>> In other words the list of symbols to be completely external to the code >>> that is defining them? >> >> Some static symbols are indeed part of kallsyms. But some symbols are >> not exported, for example patch 20/29, where printk related symbols are >> not to be exported. Another example is with static variables, like in >> patch 17/29 , not exported as symbols, but required for the dump. >> Dynamic memory regions are not have to also be considered, have a look >> for example at patch 23/29 , where dynamically allocated memory needs to >> be registered. >> >> Do you think that I should move all kallsyms related symbols annotation >> into a separate place and keep it for the static/dynamic regions in place ? > > If you want to use a symbol from kmemdump, then make that symbol > available to kmemdump. That's what I am doing, registering symbols with kmemdump. Maybe I do not understand what you mean, do you have any suggestion for the static variables case (symbols not exported) ? > > IOW, if we were to rip out kmemdump tomorrow, we wouldn't have to touch > any non-kmemdump-specific files. >
