Re: arm32: panic in move_freepages (Was [PATCH v2 0/4] arm64: drop pfn_valid_within() and simplify pfn_valid())

From: Mike Rapoport
Date: Thu Apr 29 2021 - 02:58:07 EST


On Thu, Apr 29, 2021 at 08:48:26AM +0800, Kefeng Wang wrote:
>
> On 2021/4/28 13:59, Mike Rapoport wrote:
> > On Tue, Apr 27, 2021 at 07:08:59PM +0800, Kefeng Wang wrote:
> > > On 2021/4/27 14:23, Mike Rapoport wrote:
> > > > On Mon, Apr 26, 2021 at 11:26:38PM +0800, Kefeng Wang wrote:
> > > > > On 2021/4/26 13:20, Mike Rapoport wrote:
> > > > > > On Sun, Apr 25, 2021 at 03:51:56PM +0800, Kefeng Wang wrote:
> > > > > > > On 2021/4/25 15:19, Mike Rapoport wrote:
> > > > > > >
> > > > > > > On Fri, Apr 23, 2021 at 04:11:16PM +0800, Kefeng Wang wrote:
> > > > > > >
> > > > > > > I tested this patchset(plus arm32 change, like arm64 does)
> > > > > > > based on lts 5.10,add some debug log, the useful info shows
> > > > > > > below, if we enable HOLES_IN_ZONE, no panic, any idea,
> > > > > > > thanks.
> > > > > > >
> > > > > > > Are there any changes on top of 5.10 except for pfn_valid() patch?
> > > > > > > Do you see this panic on 5.10 without the changes?
> > > > > > >
> > > > > > > Yes, there are some BSP support for arm board based on 5.10,
> > > > Is it possible to test 5.12?
> > Do you use SPARSMEM? If yes, what is your section size?
> > What is the value if CONFIG_FORCE_MAX_ZONEORDER in your configuration?
>
> Yes,
>
> CONFIG_SPARSEMEM=y
>
> CONFIG_SPARSEMEM_STATIC=y
>
> CONFIG_FORCE_MAX_ZONEORDER = 11
>
> CONFIG_PAGE_OFFSET=0xC0000000
> CONFIG_HAVE_ARCH_PFN_VALID=y
> CONFIG_HIGHMEM=y
> #define SECTION_SIZE_BITS 26
> #define MAX_PHYSADDR_BITS 32
> #define MAX_PHYSMEM_BITS 32

It seems that with SPARSEMEM we don't align the freed parts on pageblock
boundaries.

Can you try the patch below:

diff --git a/mm/memblock.c b/mm/memblock.c
index afaefa8fc6ab..1926369b52ec 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -1941,14 +1941,13 @@ static void __init free_unused_memmap(void)
* due to SPARSEMEM sections which aren't present.
*/
start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
-#else
+#endif
/*
* Align down here since the VM subsystem insists that the
* memmap entries are valid from the bank start aligned to
* MAX_ORDER_NR_PAGES.
*/
start = round_down(start, MAX_ORDER_NR_PAGES);
-#endif

/*
* If we had a previous bank, and there is a space


--
Sincerely yours,
Mike.