Re: [PATCH v2 3/3] arm: extend pfn_valid to take into accound freed memory map alignment

From: Tony Lindgren
Date: Tue Jun 29 2021 - 08:54:10 EST


* Mike Rapoport <rppt@xxxxxxxxxxxxx> [210629 12:50]:
> On Tue, Jun 29, 2021 at 02:52:39PM +0300, Tony Lindgren wrote:
> > * Mike Rapoport <rppt@xxxxxxxxxxxxx> [210629 10:51]:
> > > As it seems, the new version of pfn_valid() decides that last pages are not
> > > valid because of the overflow in memblock_overlaps_region(). As the result,
> > > __sync_icache_dcache() skips flushing these pages.
> > >
> > > The patch below should fix this. I've left the prints for now, hopefully
> > > they will not appear anymore.
> >
> > Yes this allows the system to boot for me :)
> >
> > I'm still seeing these three prints though:
> >
> > ...
> > smp: Brought up 1 node, 2 CPUs
> > SMP: Total of 2 processors activated (3994.41 BogoMIPS).
> > CPU: All CPU(s) started in SVC mode.
> > pfn_valid(__pageblock_pfn_to_page+0x14/0xa8): pfn: afe00: is_map: 0 overlaps: 1
> > pfn_valid(__pageblock_pfn_to_page+0x28/0xa8): pfn: affff: is_map: 0 overlaps: 1
> > pfn_valid(__pageblock_pfn_to_page+0x38/0xa8): pfn: afe00: is_map: 0 overlaps: 1
>
> These pfns do have memory map despite they are stolen in
> arm_memblock_steal():
>
> memblock_free: [0xaff00000-0xafffffff] arm_memblock_steal+0x50/0x70
> memblock_remove: [0xaff00000-0xafffffff] arm_memblock_steal+0x5c/0x70
> ...
> memblock_free: [0xafe00000-0xafefffff] arm_memblock_steal+0x50/0x70
> memblock_remove: [0xafe00000-0xafefffff] arm_memblock_steal+0x5c/0x70
>
> But the struct pages there are never initialized.
>
> I'll resend v3 of the entire set with an addition patch to take care of
> that as well.

OK sounds good to me :)

Thanks,

Tony