Re: [PATCH v2 1/3] Revert "x86/e820: put !E820_TYPE_RAM regions into memblock.reserved"

From: Masayoshi Mizuma
Date: Tue Oct 02 2018 - 09:51:51 EST


On Tue, Oct 02, 2018 at 11:39:40AM +0200, Ingo Molnar wrote:
>
> * Masayoshi Mizuma <msys.mizuma@xxxxxxxxx> wrote:
>
> > From: Masayoshi Mizuma <m.mizuma@xxxxxxxxxxxxxx>
> >
> > commit 124049decbb1 ("x86/e820: put !E820_TYPE_RAM regions into
> > memblock.reserved") breaks movable_node kernel option because it
> > changed the memory gap range to reserved memblock. So, the node
> > is marked as Normal zone even if the SRAT has Hot plaggable affinity.
> >
> > =====================================================================
> > kernel: BIOS-e820: [mem 0x0000180000000000-0x0000180fffffffff] usable
> > kernel: BIOS-e820: [mem 0x00001c0000000000-0x00001c0fffffffff] usable
> > ...
> > kernel: reserved[0x12]#011[0x0000181000000000-0x00001bffffffffff], 0x000003f000000000 bytes flags: 0x0
> > ...
> > kernel: ACPI: SRAT: Node 2 PXM 6 [mem 0x180000000000-0x1bffffffffff] hotplug
> > kernel: ACPI: SRAT: Node 3 PXM 7 [mem 0x1c0000000000-0x1fffffffffff] hotplug
> > ...
> > kernel: Movable zone start for each node
> > kernel: Node 3: 0x00001c0000000000
> > kernel: Early memory node ranges
> > ...
> > =====================================================================
> >
> > Naoya's v1 patch [*] fixes the original issue and this movable_node
> > issue doesn't occur.
> > Let's revert commit 124049decbb1 ("x86/e820: put !E820_TYPE_RAM
> > regions into memblock.reserved") and apply the v1 patch.
> >
> > [*] https://lkml.org/lkml/2018/6/13/27
> >
> > Signed-off-by: Masayoshi Mizuma <m.mizuma@xxxxxxxxxxxxxx>
> > Reviewed-by: Pavel Tatashin <pavel.tatashin@xxxxxxxxxxxxx>
> > ---
> > arch/x86/kernel/e820.c | 15 +++------------
> > 1 file changed, 3 insertions(+), 12 deletions(-)
>
> Bad ordering which introduces the bug and thus breaks bisection of related issues: the fixes
> should come first, then the revert of the unnecessary or bad fix.

Thanks. I'll change the order, then resend them.

- Masa