On Thu 2024-07-25 16:19:30, Miroslav Benes wrote: > On Fri, 10 Nov 2023, Josh Poimboeuf wrote: > > > On Fri, Nov 10, 2023 at 06:04:21PM +0100, Petr Mladek wrote: > > > This POC is a material for the discussion "Simplify Livepatch Callbacks, > > > Shadow Variables, and States handling" at LPC 2013, see > > > https://lpc.events/event/17/contributions/1541/ > > > > > > It obsoletes the patchset adding the garbage collection of shadow > > > variables. This new solution is based on ideas from Nicolai Stange. > > > And it should also be in sync with Josh's ideas mentioned into > > > the thread about the garbage collection, see > > > https://lore.kernel.org/r/20230204235910.4j4ame5ntqogqi7m@treble > > > > Nice! I like how it brings the "features" together and makes them easy > > to use. This looks like a vast improvement. > > > > Was there a reason to change the naming? I'm thinking > > > > setup / enable / disable / release > > > > is less precise than > > > > pre_patch / post_patch / pre_unpatch / post_unpatch. I wanted to point out that the callbacks are called _only_ when the states are added or removed. They are not called when the state is preserved during the atomic replace. The pre_patch... naming scheme might create an assumption that they are _always_ called during the livepatch transition. But I see that the new names might be misleading in other ways. I am going to use the "pre_patch..." names in the next version of the patchset. > > Also, I'm thinking "replaced" instead of "obsolete" would be more > > consistent with the existing terminology. > > > > For example, in __klp_enable_patch(): > > > > ret = klp_setup_states(patch); > > if (ret) > > goto err; > > > > if (patch->replace) > > klp_disable_obsolete_states(patch); > > > > it's not immediately clear why "disable obsolete" would be the "replace" > > counterpart to "setup". > > > > Similarly, in klp_complete_transition(): > > > > if (klp_transition_patch->replace && klp_target_state == KLP_PATCHED) { > > klp_unpatch_replaced_patches(klp_transition_patch); > > klp_discard_nops(klp_transition_patch); > > klp_release_obsolete_states(klp_transition_patch); > > } > > > > it's a little jarring to have "unpatch replaced" followed by "release > > obsolete". I see. > I agree. I would also stick to the existing naming. It is clearer to me. Fair enough. Best Regards, Petr
