On 08/24/2020 09:34 AM, Anshuman Khandual wrote: > This brings about three different changes to the sole memory event notifier > for arm64 platform and improves it's robustness while also enhancing debug > capabilities during potential memory offlining error conditions. > > This moves the memory notifier registration bit earlier in the boot process > from device_initcall() to setup_arch() which will help in guarding against > potential early boot memory offline requests. > > This enables MEM_OFFLINE memory event handling. It will help intercept any > possible error condition such as if boot memory some how still got offlined > even after an expilicit notifier failure, potentially by a future change in > generic hotplug framework. This would help detect such scenarious and help > debug further. > > It also adds a validation function which scans entire boot memory and makes > sure that early memory sections are online. This check is essential for the > memory notifier to work properly as it cannot prevent boot memory offlining > if they are not online to begin with. But this additional sanity check is > enabled only with DEBUG_VM. > > Cc: Catalin Marinas <catalin.mari...@arm.com> > Cc: Will Deacon <w...@kernel.com> > Cc: Mark Rutland <mark.rutl...@arm.com> > Cc: Marc Zyngier <m...@kernel.org> > Cc: Steve Capper <steve.cap...@arm.com> > Cc: Mark Brown <broo...@kernel.org> > Cc: linux-arm-ker...@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Anshuman Khandual <anshuman.khand...@arm.com> > --- > This applies on 5.9-rc2 > > Changes in V2: > > - Dropped all generic changes wrt MEM_CANCEL_OFFLINE reasons enumeration > - Dropped all related (processing MEM_CANCEL_OFFLINE reasons) changes on arm64 > - Added validate_boot_mem_online_state() that gets called with > early_initcall() > - Added CONFIG_MEMORY_HOTREMOVE check before registering memory notifier > - Moved notifier registration i.e memory_hotremove_notifier into setup_arch() Gentle ping, any updates on this ?
