On 06.01.2025 19:09, Tamas K Lengyel wrote: > On Mon, Jan 6, 2025 at 10:10 AM Jan Beulich <jbeul...@suse.com> wrote: >> >> On 06.01.2025 15:05, Tamas K Lengyel wrote: >>> On Mon, Jan 6, 2025 at 5:16 AM Jan Beulich <jbeul...@suse.com> wrote: >>>> >>>> On 30.12.2024 07:30, Sergiy Kibrik wrote: >>>>> From: Stefano Stabellini <stefano.stabell...@amd.com> >>>>> >>>>> Extend coverage of CONFIG_MEM_ACCESS option and make the build of VM >>>>> events >>>>> and monitoring support optional. >>>> >>>> Yet doesn't this end up in things becoming misleading? Don't we rather >>>> need a >>>> 2nd Kconfig option, with a dependency between the two? Or alternatively a >>>> rename of the existing option (to describe the higher-level feature rather >>>> than the lower level one)? Tamas, I'm particularly interested in knowing >>>> your >>>> view here as well. >>> >>> Thanks Jan, I was thinking the same thing. The dependency of these >>> subsystems is mem_access -> monitor -> vm_event. If the goal here is >>> to disable all three levels the ideal way would be to have separate >>> kconfig options for each level. It may be a bit too fine-grained >>> though on ARM since there are only two types of events for monitor >>> (SMC & mem_access) and only the monitor uses the vm_event channel (no >>> mem-sharing/paging on ARM). So if doing separate kconfig for each >>> individual feature is an overkill I would suggest using >>> CONFIG_VM_EVENT that disables all three levels, including both >>> mem_access & smc monitor hooks. >> >> Except that "disables all three levels" doesn't work, unless the other >> option(s) are promptless (and selected). I'd have expected VM_EVENT to >> maybe have a "depends on MEM_ACCESS", whereas a "select MEM_ACCESS" >> wouldn't make much sense as long as MEM_ACCESS can be enabled >> individually (with it being unclear to me whether such a configuration >> is actually useful in any way). > > Not sure I follow. None of these systems make sense to enable > individually. Without vm_event monitor/mem_access are useless, that's > why I would pick CONFIG_VM_EVENT as the option on ARM to disable all > three levels if we don't want to start splitting it into multiple > kconfig options (which I think may be an overkill here).
Oh, okay, you suggest to replace MEM_ACCESS by VM_EVENT at the Kconfig level. That would be fine with me, so long as it's also appropriate on (in particular) x86. Then, if there was ever a 2nd use of mem-access, MEM_ACCESS could be re-introduced as a standalone option. Jan
