mm: unify the allocation of pglist_data instances

This patches is created to fix the __pa() warning messages when
CONFIG_DEBUG_VIRTUAL=y by unifying the allocation of pglist_data
instances.

In current implementation of node_data, if CONFIG_NEED_MULTIPLE_NODES=y,
pglist_data is allocated by a memblock API. If CONFIG_NEED_MULTIPLE_NODES=n,
we use a global variable named "contig_page_data".

If CONFIG_DEBUG_VIRTUAL is not enabled. __pa() can handle both
allocation and symbol cases. But if CONFIG_DEBUG_VIRTUAL is set,
we will have the "virt_to_phys used for non-linear address" warning
when booting.

To fix the warning, always allocate pglist_data by memblock APIs and
remove the usage of contig_page_data.

Warning message:
[    0.000000] ------------[ cut here ]------------
[    0.000000] virt_to_phys used for non-linear address: (____ptrval____) (contig_page_data+0x0/0x1c00)
[    0.000000] WARNING: CPU: 0 PID: 0 at arch/arm64/mm/physaddr.c:15 __virt_to_phys+0x58/0x68
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Tainted: G        W         5.13.0-rc1-00074-g1140ab592e2e #3
[    0.000000] Hardware name: linux,dummy-virt (DT)
[    0.000000] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO BTYPE=--)
[    0.000000] pc : __virt_to_phys+0x58/0x68
[    0.000000] lr : __virt_to_phys+0x54/0x68
[    0.000000] sp : ffff800011833e70
[    0.000000] x29: ffff800011833e70 x28: 00000000418a0018 x27: 0000000000000000
[    0.000000] x26: 000000000000000a x25: ffff800011b70000 x24: ffff800011b70000
[    0.000000] x23: fffffc0001c00000 x22: ffff800011b70000 x21: 0000000047ffffb0
[    0.000000] x20: 0000000000000008 x19: ffff800011b082c0 x18: ffffffffffffffff
[    0.000000] x17: 0000000000000000 x16: ffff800011833bf9 x15: 0000000000000004
[    0.000000] x14: 0000000000000fff x13: ffff80001186a548 x12: 0000000000000000
[    0.000000] x11: 0000000000000000 x10: 00000000ffffffff x9 : 0000000000000000
[    0.000000] x8 : ffff8000115c9000 x7 : 737520737968705f x6 : ffff800011b62ef8
[    0.000000] x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
[    0.000000] x2 : 0000000000000000 x1 : ffff80001159585e x0 : 0000000000000058
[    0.000000] Call trace:
[    0.000000]  __virt_to_phys+0x58/0x68
[    0.000000]  check_usemap_section_nr+0x50/0xfc

32 more lines

Replace contig_page_data with node_data. Change the definition
of NODE_DATA(nid) from (&contig_page_data) to (node_data[0]).

Remove contig_page_data from the tree.

Cc: Mike Rapoport <rppt@kernel.org>
Cc: Baoquan He <redacted>
Cc: Kazu <redacted>
Signed-off-by: Miles Chen <redacted>
---
 Documentation/admin-guide/kdump/vmcoreinfo.rst | 13 -------------
 arch/powerpc/kexec/core.c                      |  5 -----
 include/linux/gfp.h                            |  3 ---
 include/linux/mmzone.h                         |  3 +--
 kernel/crash_core.c                            |  1 -
 mm/memblock.c                                  |  2 --
 6 files changed, 1 insertion(+), 26 deletions(-)

diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst
index 3861a25faae1..74185245c580 100644
--- a/Documentation/admin-guide/kdump/vmcoreinfo.rst
+++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst

@@ -81,14 +81,6 @@ into that mem_map array.
 
 Used to map an address to the corresponding struct page.
 
-contig_page_data
-----------------
-
-Makedumpfile gets the pglist_data structure from this symbol, which is
-used to describe the memory layout.
-
-User-space tools use this to exclude free pages when dumping memory.
-
 mem_section|(mem_section, NR_SECTION_ROOTS)|(mem_section, section_mem_map)
 --------------------------------------------------------------------------
 

@@ -531,11 +523,6 @@ node_data|(node_data, MAX_NUMNODES)
 
 See above.
 
-contig_page_data
-----------------
-
-See above.
-
 vmemmap_list
 ------------
 

diff --git a/arch/powerpc/kexec/core.c b/arch/powerpc/kexec/core.c
index 56da5eb2b923..41f31dfb540c 100644
--- a/arch/powerpc/kexec/core.c
+++ b/arch/powerpc/kexec/core.c

@@ -68,13 +68,8 @@ void machine_kexec_cleanup(struct kimage *image)
 void arch_crash_save_vmcoreinfo(void)
 {
 
-#ifdef CONFIG_NEED_MULTIPLE_NODES
 	VMCOREINFO_SYMBOL(node_data);
 	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
-#endif
-#ifndef CONFIG_NEED_MULTIPLE_NODES
-	VMCOREINFO_SYMBOL(contig_page_data);
-#endif
 #if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP)
 	VMCOREINFO_SYMBOL(vmemmap_list);
 	VMCOREINFO_SYMBOL(mmu_vmemmap_psize);

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 11da8af06704..ba8c511c402f 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h

@@ -493,9 +493,6 @@ static inline int gfp_zonelist(gfp_t flags)
  * This zone list contains a maximum of MAX_NUMNODES*MAX_NR_ZONES zones.
  * There are two zonelists per node, one for all zones with memory and
  * one containing just zones from the node the zonelist belongs to.
- *
- * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
- * optimized to &contig_page_data at compile-time.
  */
 static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
 {

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 557918dcc755..c0769292187c 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h

@@ -1043,9 +1043,8 @@ extern char numa_zonelist_order[];
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 
-extern struct pglist_data contig_page_data;
-#define NODE_DATA(nid)		(&contig_page_data)
 extern struct pglist_data *node_data[];
+#define NODE_DATA(nid)		(node_data[0])
 #define NODE_MEM_MAP(nid)	mem_map
 
 #else /* CONFIG_NEED_MULTIPLE_NODES */

diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 825284baaf46..d1e324be67f9 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c

@@ -457,7 +457,6 @@ static int __init crash_save_vmcoreinfo_init(void)
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 	VMCOREINFO_SYMBOL(mem_map);
-	VMCOREINFO_SYMBOL(contig_page_data);
 #endif
 #ifdef CONFIG_SPARSEMEM
 	VMCOREINFO_SYMBOL_ARRAY(mem_section);

diff --git a/mm/memblock.c b/mm/memblock.c
index ebddb57ea62d..7cfc9a9d6243 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c

@@ -93,8 +93,6 @@
  */
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES
-struct pglist_data __refdata contig_page_data;
-EXPORT_SYMBOL(contig_page_data);
 struct pglist_data *node_data[MAX_NUMNODES];
 #endif
 

-- 
2.18.0

When CONFIG_NEED_MULTIPLE_NODES=y (CONFIG_NUMA=y),
the pglist_data is allocated by a memblock API and stored in an array
named node_data[].
When CONFIG_NEED_MULTIPLE_NODES=n (CONFIG_NUMA=n), the pglist_data
is defined as global variable contig_page_data. The difference
causes problems when we enable CONFIG_DEBUG_VIRTUAL and use __pa()
to get the physical address of NODE_DATA.

To solve the issue, introduce prepare_node_data() to allocate
pglist_data when CONFIG_NUMA=n and stored it to node_data.
i.e., Use the same way to allocate node_data[] when CONFIG_NUMA=y
or CONFIG_NUMA=n.
prepare_node_data() is called in sparer_init() and
free_area_init().

This is the first step to replace contig_page_data with allocated
pglist_data.

Cc: Mike Rapoport <rppt@kernel.org>
Cc: Baoquan He <redacted>
Cc: Kazu <redacted>
Signed-off-by: Miles Chen <redacted>
---
 include/linux/mm.h     |  2 ++
 include/linux/mmzone.h |  1 +
 mm/memblock.c          |  1 +
 mm/page_alloc.c        | 16 ++++++++++++++++
 mm/sparse.c            |  2 ++
 5 files changed, 22 insertions(+)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index c274f75efcf9..3052eeb87455 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h

@@ -2462,9 +2462,11 @@ static inline int early_pfn_to_nid(unsigned long pfn)
 {
 	return 0;
 }
+extern void prepare_node_data(void);
 #else
 /* please see mm/page_alloc.c */
 extern int __meminit early_pfn_to_nid(unsigned long pfn);
+static inline void prepare_node_data(void) {};
 #endif
 
 extern void set_dma_reserve(unsigned long new_dma_reserve);

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 0d53eba1c383..557918dcc755 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h

@@ -1045,6 +1045,7 @@ extern char numa_zonelist_order[];
 
 extern struct pglist_data contig_page_data;
 #define NODE_DATA(nid)		(&contig_page_data)
+extern struct pglist_data *node_data[];
 #define NODE_MEM_MAP(nid)	mem_map
 
 #else /* CONFIG_NEED_MULTIPLE_NODES */

diff --git a/mm/memblock.c b/mm/memblock.c
index afaefa8fc6ab..ebddb57ea62d 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c

@@ -95,6 +95,7 @@
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 struct pglist_data __refdata contig_page_data;
 EXPORT_SYMBOL(contig_page_data);
+struct pglist_data *node_data[MAX_NUMNODES];
 #endif
 
 unsigned long max_low_pfn;

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index aaa1655cf682..0c6d421f4cfb 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c

@@ -1659,6 +1659,20 @@ int __meminit early_pfn_to_nid(unsigned long pfn)
 
 	return nid;
 }
+#else
+void __init prepare_node_data(void)
+{
+	if (node_data[0])
+		return;
+
+	node_data[0] = memblock_alloc(sizeof(struct pglist_data),
+			SMP_CACHE_BYTES);
+
+	if (!node_data[0])
+		panic("Cannot allocate node_data\n");
+
+	memset(node_data[0], 0, sizeof(struct pglist_data));
+}
 #endif /* CONFIG_NEED_MULTIPLE_NODES */
 
 void __init memblock_free_pages(struct page *page, unsigned long pfn,

@@ -7697,6 +7711,8 @@ void __init free_area_init(unsigned long *max_zone_pfn)
 	int i, nid, zone;
 	bool descending;
 
+	prepare_node_data();
+
 	/* Record where the zone boundaries are */
 	memset(arch_zone_lowest_possible_pfn, 0,
 				sizeof(arch_zone_lowest_possible_pfn));

diff --git a/mm/sparse.c b/mm/sparse.c
index b2ada9dc00cb..afcfe7463b4a 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c

@@ -580,6 +580,8 @@ void __init sparse_init(void)
 
 	memblocks_present();
 
+	prepare_node_data();
+
 	pnum_begin = first_present_section_nr();
 	nid_begin = sparse_early_nid(__nr_to_section(pnum_begin));
 

-- 
2.18.0

Hello Miles,

On Tue, May 18, 2021 at 05:24:44PM +0800, Miles Chen wrote:

This patches is created to fix the __pa() warning messages when
CONFIG_DEBUG_VIRTUAL=y by unifying the allocation of pglist_data
instances.

In current implementation of node_data, if CONFIG_NEED_MULTIPLE_NODES=y,
pglist_data is allocated by a memblock API. If CONFIG_NEED_MULTIPLE_NODES=n,
we use a global variable named "contig_page_data".

If CONFIG_DEBUG_VIRTUAL is not enabled. __pa() can handle both
allocation and symbol cases. But if CONFIG_DEBUG_VIRTUAL is set,
we will have the "virt_to_phys used for non-linear address" warning
when booting.

To fix the warning, always allocate pglist_data by memblock APIs and
remove the usage of contig_page_data.

Somehow I was sure that we can allocate pglist_data before it is accessed
in sparse_init() somewhere outside mm/sparse.c. It's really not the case
and having two places that may allocated this structure is surely worth
than your previous suggestion.

Sorry about that.
 

Warning message:
[    0.000000] ------------[ cut here ]------------
[    0.000000] virt_to_phys used for non-linear address: (____ptrval____) (contig_page_data+0x0/0x1c00)
[    0.000000] WARNING: CPU: 0 PID: 0 at arch/arm64/mm/physaddr.c:15 __virt_to_phys+0x58/0x68
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Tainted: G        W         5.13.0-rc1-00074-g1140ab592e2e #3
[    0.000000] Hardware name: linux,dummy-virt (DT)
[    0.000000] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO BTYPE=--)
[    0.000000] pc : __virt_to_phys+0x58/0x68
[    0.000000] lr : __virt_to_phys+0x54/0x68
[    0.000000] sp : ffff800011833e70
[    0.000000] x29: ffff800011833e70 x28: 00000000418a0018 x27: 0000000000000000
[    0.000000] x26: 000000000000000a x25: ffff800011b70000 x24: ffff800011b70000
[    0.000000] x23: fffffc0001c00000 x22: ffff800011b70000 x21: 0000000047ffffb0
[    0.000000] x20: 0000000000000008 x19: ffff800011b082c0 x18: ffffffffffffffff
[    0.000000] x17: 0000000000000000 x16: ffff800011833bf9 x15: 0000000000000004
[    0.000000] x14: 0000000000000fff x13: ffff80001186a548 x12: 0000000000000000
[    0.000000] x11: 0000000000000000 x10: 00000000ffffffff x9 : 0000000000000000
[    0.000000] x8 : ffff8000115c9000 x7 : 737520737968705f x6 : ffff800011b62ef8
[    0.000000] x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
[    0.000000] x2 : 0000000000000000 x1 : ffff80001159585e x0 : 0000000000000058
[    0.000000] Call trace:
[    0.000000]  __virt_to_phys+0x58/0x68
[    0.000000]  check_usemap_section_nr+0x50/0xfc
[    0.000000]  sparse_init_nid+0x1ac/0x28c
[    0.000000]  sparse_init+0x1c4/0x1e0
[    0.000000]  bootmem_init+0x60/0x90
[    0.000000]  setup_arch+0x184/0x1f0
[    0.000000]  start_kernel+0x78/0x488
[    0.000000] ---[ end trace f68728a0d3053b60 ]---

[1] https://lore.kernel.org/patchwork/patch/1425110/

Change since v1:
- use memblock_alloc() to create pglist_data when CONFIG_NUMA=n

Miles Chen (2):
  mm: introduce prepare_node_data
  mm: replace contig_page_data with node_data

16 more quoted lines

-- 
Sincerely yours,
Mike.

On Tue, 2021-05-18 at 19:09 +0300, Mike Rapoport wrote:

Hello Miles,

On Tue, May 18, 2021 at 05:24:44PM +0800, Miles Chen wrote:

quoted

This patches is created to fix the __pa() warning messages when
CONFIG_DEBUG_VIRTUAL=y by unifying the allocation of pglist_data
instances.

In current implementation of node_data, if CONFIG_NEED_MULTIPLE_NODES=y,
pglist_data is allocated by a memblock API. If CONFIG_NEED_MULTIPLE_NODES=n,
we use a global variable named "contig_page_data".

If CONFIG_DEBUG_VIRTUAL is not enabled. __pa() can handle both
allocation and symbol cases. But if CONFIG_DEBUG_VIRTUAL is set,
we will have the "virt_to_phys used for non-linear address" warning
when booting.

To fix the warning, always allocate pglist_data by memblock APIs and
remove the usage of contig_page_data.

Somehow I was sure that we can allocate pglist_data before it is accessed
in sparse_init() somewhere outside mm/sparse.c. It's really not the case
and having two places that may allocated this structure is surely worth
than your previous suggestion.

Sorry about that.

Do you mean taht to call allocation function arch/*, somewhere after
paging_init() (so we can access pglist_data) and before sparse_init()
and free_area_init()?

Miles

quoted

Warning message:
[    0.000000] ------------[ cut here ]------------
[    0.000000] virt_to_phys used for non-linear address: (____ptrval____) (contig_page_data+0x0/0x1c00)
[    0.000000] WARNING: CPU: 0 PID: 0 at arch/arm64/mm/physaddr.c:15 __virt_to_phys+0x58/0x68
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Tainted: G        W         5.13.0-rc1-00074-g1140ab592e2e #3
[    0.000000] Hardware name: linux,dummy-virt (DT)
[    0.000000] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO BTYPE=--)
[    0.000000] pc : __virt_to_phys+0x58/0x68
[    0.000000] lr : __virt_to_phys+0x54/0x68
[    0.000000] sp : ffff800011833e70
[    0.000000] x29: ffff800011833e70 x28: 00000000418a0018 x27: 0000000000000000
[    0.000000] x26: 000000000000000a x25: ffff800011b70000 x24: ffff800011b70000
[    0.000000] x23: fffffc0001c00000 x22: ffff800011b70000 x21: 0000000047ffffb0
[    0.000000] x20: 0000000000000008 x19: ffff800011b082c0 x18: ffffffffffffffff
[    0.000000] x17: 0000000000000000 x16: ffff800011833bf9 x15: 0000000000000004
[    0.000000] x14: 0000000000000fff x13: ffff80001186a548 x12: 0000000000000000
[    0.000000] x11: 0000000000000000 x10: 00000000ffffffff x9 : 0000000000000000
[    0.000000] x8 : ffff8000115c9000 x7 : 737520737968705f x6 : ffff800011b62ef8
[    0.000000] x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
[    0.000000] x2 : 0000000000000000 x1 : ffff80001159585e x0 : 0000000000000058
[    0.000000] Call trace:
[    0.000000]  __virt_to_phys+0x58/0x68
[    0.000000]  check_usemap_section_nr+0x50/0xfc
[    0.000000]  sparse_init_nid+0x1ac/0x28c
[    0.000000]  sparse_init+0x1c4/0x1e0
[    0.000000]  bootmem_init+0x60/0x90
[    0.000000]  setup_arch+0x184/0x1f0
[    0.000000]  start_kernel+0x78/0x488
[    0.000000] ---[ end trace f68728a0d3053b60 ]---

[1] https://urldefense.com/v3/__https://lore.kernel.org/patchwork/patch/1425110/__;!!CTRNKA9wMg0ARbw!x-wGFEC1wLzXho2kI1CrC2fjXNaQm5f-n0ADQyJDckCOKZHAP_q055DCSWYcQ7Zdcw$ 

Change since v1:
- use memblock_alloc() to create pglist_data when CONFIG_NUMA=n

Miles Chen (2):
  mm: introduce prepare_node_data
  mm: replace contig_page_data with node_data

18 more quoted lines

On Wed, May 19, 2021 at 08:12:06AM +0800, Miles Chen wrote:

On Tue, 2021-05-18 at 19:09 +0300, Mike Rapoport wrote:

quoted

Hello Miles,

On Tue, May 18, 2021 at 05:24:44PM +0800, Miles Chen wrote:

quoted

This patches is created to fix the __pa() warning messages when
CONFIG_DEBUG_VIRTUAL=y by unifying the allocation of pglist_data
instances.

In current implementation of node_data, if CONFIG_NEED_MULTIPLE_NODES=y,
pglist_data is allocated by a memblock API. If CONFIG_NEED_MULTIPLE_NODES=n,
we use a global variable named "contig_page_data".

If CONFIG_DEBUG_VIRTUAL is not enabled. __pa() can handle both
allocation and symbol cases. But if CONFIG_DEBUG_VIRTUAL is set,
we will have the "virt_to_phys used for non-linear address" warning
when booting.

To fix the warning, always allocate pglist_data by memblock APIs and
remove the usage of contig_page_data.

Somehow I was sure that we can allocate pglist_data before it is accessed
in sparse_init() somewhere outside mm/sparse.c. It's really not the case
and having two places that may allocated this structure is surely worth
than your previous suggestion.

Sorry about that.

Do you mean taht to call allocation function arch/*, somewhere after
paging_init() (so we can access pglist_data) and before sparse_init()
and free_area_init()?

No, I meant that your original patch is better than adding allocation of
NODE_DATA(0) in two places.
 

Miles

quoted

quoted

Warning message:
[    0.000000] ------------[ cut here ]------------
[    0.000000] virt_to_phys used for non-linear address: (____ptrval____) (contig_page_data+0x0/0x1c00)
[    0.000000] WARNING: CPU: 0 PID: 0 at arch/arm64/mm/physaddr.c:15 __virt_to_phys+0x58/0x68
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Tainted: G        W         5.13.0-rc1-00074-g1140ab592e2e #3
[    0.000000] Hardware name: linux,dummy-virt (DT)
[    0.000000] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO BTYPE=--)
[    0.000000] pc : __virt_to_phys+0x58/0x68
[    0.000000] lr : __virt_to_phys+0x54/0x68
[    0.000000] sp : ffff800011833e70
[    0.000000] x29: ffff800011833e70 x28: 00000000418a0018 x27: 0000000000000000
[    0.000000] x26: 000000000000000a x25: ffff800011b70000 x24: ffff800011b70000
[    0.000000] x23: fffffc0001c00000 x22: ffff800011b70000 x21: 0000000047ffffb0
[    0.000000] x20: 0000000000000008 x19: ffff800011b082c0 x18: ffffffffffffffff
[    0.000000] x17: 0000000000000000 x16: ffff800011833bf9 x15: 0000000000000004
[    0.000000] x14: 0000000000000fff x13: ffff80001186a548 x12: 0000000000000000
[    0.000000] x11: 0000000000000000 x10: 00000000ffffffff x9 : 0000000000000000
[    0.000000] x8 : ffff8000115c9000 x7 : 737520737968705f x6 : ffff800011b62ef8
[    0.000000] x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
[    0.000000] x2 : 0000000000000000 x1 : ffff80001159585e x0 : 0000000000000058
[    0.000000] Call trace:
[    0.000000]  __virt_to_phys+0x58/0x68
[    0.000000]  check_usemap_section_nr+0x50/0xfc
[    0.000000]  sparse_init_nid+0x1ac/0x28c
[    0.000000]  sparse_init+0x1c4/0x1e0
[    0.000000]  bootmem_init+0x60/0x90
[    0.000000]  setup_arch+0x184/0x1f0
[    0.000000]  start_kernel+0x78/0x488
[    0.000000] ---[ end trace f68728a0d3053b60 ]---

[1] https://urldefense.com/v3/__https://lore.kernel.org/patchwork/patch/1425110/__;!!CTRNKA9wMg0ARbw!x-wGFEC1wLzXho2kI1CrC2fjXNaQm5f-n0ADQyJDckCOKZHAP_q055DCSWYcQ7Zdcw$ 

Change since v1:
- use memblock_alloc() to create pglist_data when CONFIG_NUMA=n

Miles Chen (2):

21 more quoted lines

-- 
Sincerely yours,
Mike.

On Wed, 2021-05-19 at 06:48 +0300, Mike Rapoport wrote:

On Wed, May 19, 2021 at 08:12:06AM +0800, Miles Chen wrote:

quoted

On Tue, 2021-05-18 at 19:09 +0300, Mike Rapoport wrote:

quoted

Hello Miles,

On Tue, May 18, 2021 at 05:24:44PM +0800, Miles Chen wrote:

quoted

This patches is created to fix the __pa() warning messages when
CONFIG_DEBUG_VIRTUAL=y by unifying the allocation of pglist_data
instances.

In current implementation of node_data, if CONFIG_NEED_MULTIPLE_NODES=y,
pglist_data is allocated by a memblock API. If CONFIG_NEED_MULTIPLE_NODES=n,
we use a global variable named "contig_page_data".

If CONFIG_DEBUG_VIRTUAL is not enabled. __pa() can handle both
allocation and symbol cases. But if CONFIG_DEBUG_VIRTUAL is set,
we will have the "virt_to_phys used for non-linear address" warning
when booting.

To fix the warning, always allocate pglist_data by memblock APIs and
remove the usage of contig_page_data.

Somehow I was sure that we can allocate pglist_data before it is accessed
in sparse_init() somewhere outside mm/sparse.c. It's really not the case
and having two places that may allocated this structure is surely worth
than your previous suggestion.

Sorry about that.

Do you mean taht to call allocation function arch/*, somewhere after
paging_init() (so we can access pglist_data) and before sparse_init()
and free_area_init()?

No, I meant that your original patch is better than adding allocation of
NODE_DATA(0) in two places.

Got it. will you re-review the original patch?

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Miles

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Warning message:
[    0.000000] ------------[ cut here ]------------
[    0.000000] virt_to_phys used for non-linear address: (____ptrval____) (contig_page_data+0x0/0x1c00)
[    0.000000] WARNING: CPU: 0 PID: 0 at arch/arm64/mm/physaddr.c:15 __virt_to_phys+0x58/0x68
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Tainted: G        W         5.13.0-rc1-00074-g1140ab592e2e #3
[    0.000000] Hardware name: linux,dummy-virt (DT)
[    0.000000] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO BTYPE=--)
[    0.000000] pc : __virt_to_phys+0x58/0x68
[    0.000000] lr : __virt_to_phys+0x54/0x68
[    0.000000] sp : ffff800011833e70
[    0.000000] x29: ffff800011833e70 x28: 00000000418a0018 x27: 0000000000000000
[    0.000000] x26: 000000000000000a x25: ffff800011b70000 x24: ffff800011b70000
[    0.000000] x23: fffffc0001c00000 x22: ffff800011b70000 x21: 0000000047ffffb0
[    0.000000] x20: 0000000000000008 x19: ffff800011b082c0 x18: ffffffffffffffff
[    0.000000] x17: 0000000000000000 x16: ffff800011833bf9 x15: 0000000000000004
[    0.000000] x14: 0000000000000fff x13: ffff80001186a548 x12: 0000000000000000
[    0.000000] x11: 0000000000000000 x10: 00000000ffffffff x9 : 0000000000000000
[    0.000000] x8 : ffff8000115c9000 x7 : 737520737968705f x6 : ffff800011b62ef8
[    0.000000] x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
[    0.000000] x2 : 0000000000000000 x1 : ffff80001159585e x0 : 0000000000000058
[    0.000000] Call trace:
[    0.000000]  __virt_to_phys+0x58/0x68
[    0.000000]  check_usemap_section_nr+0x50/0xfc
[    0.000000]  sparse_init_nid+0x1ac/0x28c
[    0.000000]  sparse_init+0x1c4/0x1e0
[    0.000000]  bootmem_init+0x60/0x90
[    0.000000]  setup_arch+0x184/0x1f0
[    0.000000]  start_kernel+0x78/0x488
[    0.000000] ---[ end trace f68728a0d3053b60 ]---

[1] https://urldefense.com/v3/__https://lore.kernel.org/patchwork/patch/1425110/__;!!CTRNKA9wMg0ARbw!x-wGFEC1wLzXho2kI1CrC2fjXNaQm5f-n0ADQyJDckCOKZHAP_q055DCSWYcQ7Zdcw$ 

Change since v1:
- use memblock_alloc() to create pglist_data when CONFIG_NUMA=n

23 more quoted lines