07.01.25 10:46, Jan Beulich:
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.
Thanks Jan,
would it be ok to replace MEM_ACCESS with VM_EVENT everywhere at once,
including in defconfigs and automation script etc? Or such changes would
better be done gradually, starting with changing Kconfig only?
-Sergiy
