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

From: Mike Rapoport <rppt@kernel.org>
To: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: linux-arm-kernel@lists.infradead.org,
	Andrew Morton <akpm@linux-foundation.org>,
	Anshuman Khandual <anshuman.khandual@arm.com>,
	Ard Biesheuvel <ardb@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	David Hildenbrand <david@redhat.com>,
	Marc Zyngier <maz@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Mike Rapoport <rppt@linux.ibm.com>, Will Deacon <will@kernel.org>,
	kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org
Subject: Re: arm32: panic in move_freepages (Was [PATCH v2 0/4] arm64: drop pfn_valid_within() and simplify pfn_valid())
Date: Thu, 29 Apr 2021 09:57:53 +0300	[thread overview]
Message-ID: <YIpY8TXCSc7Lfa2Z@kernel.org> (raw)
In-Reply-To: <6ad2956c-70ae-c423-ed7d-88e94c88060f@huawei.com>

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.
