Messages in this thread | | | From | Chris Goldsworthy <> | Subject | [RFC] arm64: mm: update max_pfn after memory hotplug | Date | Thu, 23 Sep 2021 15:54:47 -0700 |
| |
On arm64 we set max_pfn at boot in arch/arm64/mm/init.c. If you hotplug in memory after booting up, max_pfn is not updated. This breaks diagnostic functions executed from user space like read_page_owner():
https://elixir.bootlin.com/linux/v5.14.7/source/mm/page_owner.c#L472
or kpageflags_read() (see how get_max_dump_pfn() is used):
https://elixir.bootlin.com/linux/v5.14.7/source/fs/proc/page.c#L47
Thus, this patch updates max_pfn and max_low_pfn in arm64's arch_add_memory() function, mirroring what is updatated during boot:
https://elixir.bootlin.com/linux/v5.14.7/source/arch/arm64/mm/init.c#L448
We would appreciate feedback on any other variables that should be updated when hotplugging in memory - note that we're mirroring x86, in that max_pfn is only ever incremented when calling arch_add_memory():
https://elixir.bootlin.com/linux/v5.14.7/source/arch/x86/mm/init_64.c#L958
Sudarshan Rajagopalan (1): arm64: mm: update max_pfn after memory hotplug
arch/arm64/mm/mmu.c | 5 +++++ 1 file changed, 5 insertions(+)
-- 2.7.4
| |