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* WARNING: at mm/page_alloc.c:4514 free_area_init_node+0x4f/0x37b()
@ 2012-08-01 17:38 Borislav Petkov
  2012-08-01 23:33 ` Minchan Kim
  0 siblings, 1 reply; 5+ messages in thread
From: Borislav Petkov @ 2012-08-01 17:38 UTC (permalink / raw)
  To: Minchan Kim
  Cc: Tejun Heo, Ralf Baechle, Andrew Morton, Linus Torvalds, LKML,
	linux-mm

[-- Attachment #1: Type: text/plain, Size: 4984 bytes --]

Hi,

I'm hitting the WARN_ON in $Subject with latest linus:
v3.5-8833-g2d534926205d on a 4-node AMD system. As it looks from
dmesg, it is happening on node 0, 1 and 2 but not on 3. Probably the
pgdat->nr_zones thing but I'll have to add more dbg code to be sure.

Config is attached.

dmesg:

[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x00010000-0x00087fff]
[    0.000000]   node   0: [mem 0x00100000-0xc7ebffff]
[    0.000000]   node   0: [mem 0x100000000-0x437ffffff]
[    0.000000]   node   1: [mem 0x438000000-0x837ffffff]
[    0.000000]   node   2: [mem 0x838000000-0xc37ffffff]
[    0.000000]   node   3: [mem 0xc38000000-0x1037ffffff]
[    0.000000] On node 0 totalpages: 4193848
[    0.000000]   DMA zone: 64 pages used for memmap
[    0.000000]   DMA zone: 6 pages reserved
[    0.000000]   DMA zone: 3890 pages, LIFO batch:0
[    0.000000]   DMA32 zone: 16320 pages used for memmap
[    0.000000]   DMA32 zone: 798464 pages, LIFO batch:31
[    0.000000]   Normal zone: 52736 pages used for memmap
[    0.000000]   Normal zone: 3322368 pages, LIFO batch:31
[    0.000000] ------------[ cut here ]------------
[    0.000000] WARNING: at mm/page_alloc.c:4514 free_area_init_node+0x4f/0x37b()
[    0.000000] Hardware name: Dinar
[    0.000000] Modules linked in:
[    0.000000] Pid: 0, comm: swapper Not tainted 3.5.0+ #9
[    0.000000] Call Trace:
[    0.000000]  [<ffffffff810320bd>] warn_slowpath_common+0x85/0x9d
[    0.000000]  [<ffffffff810320ef>] warn_slowpath_null+0x1a/0x1c
[    0.000000]  [<ffffffff81470bc0>] free_area_init_node+0x4f/0x37b
[    0.000000]  [<ffffffff81af5962>] ? find_min_pfn_for_node+0x57/0x84
[    0.000000]  [<ffffffff81af61a2>] free_area_init_nodes+0x55d/0x5ac
[    0.000000]  [<ffffffff81aed7ca>] zone_sizes_init+0x3b/0x3d
[    0.000000]  [<ffffffff81aedadc>] paging_init+0x20/0x22
[    0.000000]  [<ffffffff81ae030d>] setup_arch+0x6f3/0x7c2
[    0.000000]  [<ffffffff81add806>] start_kernel+0x8f/0x2eb
[    0.000000]  [<ffffffff81add280>] x86_64_start_reservations+0x84/0x89
[    0.000000]  [<ffffffff81add377>] x86_64_start_kernel+0xf2/0xf9
[    0.000000] ---[ end trace d76bed13a5793ee3 ]---
[    0.000000] On node 1 totalpages: 4194304
[    0.000000]   Normal zone: 65536 pages used for memmap
[    0.000000]   Normal zone: 4128768 pages, LIFO batch:31
[    0.000000] ------------[ cut here ]------------
[    0.000000] WARNING: at mm/page_alloc.c:4514 free_area_init_node+0x4f/0x37b()
[    0.000000] Hardware name: Dinar
[    0.000000] Modules linked in:
[    0.000000] Pid: 0, comm: swapper Tainted: G        W    3.5.0+ #9
[    0.000000] Call Trace:
[    0.000000]  [<ffffffff810320bd>] warn_slowpath_common+0x85/0x9d
[    0.000000]  [<ffffffff810320ef>] warn_slowpath_null+0x1a/0x1c
[    0.000000]  [<ffffffff81470bc0>] free_area_init_node+0x4f/0x37b
[    0.000000]  [<ffffffff81af5962>] ? find_min_pfn_for_node+0x57/0x84
[    0.000000]  [<ffffffff81af61a2>] free_area_init_nodes+0x55d/0x5ac
[    0.000000]  [<ffffffff81aed7ca>] zone_sizes_init+0x3b/0x3d
[    0.000000]  [<ffffffff81aedadc>] paging_init+0x20/0x22
[    0.000000]  [<ffffffff81ae030d>] setup_arch+0x6f3/0x7c2
[    0.000000]  [<ffffffff81add806>] start_kernel+0x8f/0x2eb
[    0.000000]  [<ffffffff81add280>] x86_64_start_reservations+0x84/0x89
[    0.000000]  [<ffffffff81add377>] x86_64_start_kernel+0xf2/0xf9
[    0.000000] ---[ end trace d76bed13a5793ee4 ]---
[    0.000000] On node 2 totalpages: 4194304
[    0.000000]   Normal zone: 65536 pages used for memmap
[    0.000000]   Normal zone: 4128768 pages, LIFO batch:31
[    0.000000] ------------[ cut here ]------------
[    0.000000] WARNING: at mm/page_alloc.c:4514 free_area_init_node+0x4f/0x37b()
[    0.000000] Hardware name: Dinar
[    0.000000] Modules linked in:
[    0.000000] Pid: 0, comm: swapper Tainted: G        W    3.5.0+ #9
[    0.000000] Call Trace:
[    0.000000]  [<ffffffff810320bd>] warn_slowpath_common+0x85/0x9d
[    0.000000]  [<ffffffff810320ef>] warn_slowpath_null+0x1a/0x1c
[    0.000000]  [<ffffffff81470bc0>] free_area_init_node+0x4f/0x37b
[    0.000000]  [<ffffffff81af5962>] ? find_min_pfn_for_node+0x57/0x84
[    0.000000]  [<ffffffff81af61a2>] free_area_init_nodes+0x55d/0x5ac
[    0.000000]  [<ffffffff81aed7ca>] zone_sizes_init+0x3b/0x3d
[    0.000000]  [<ffffffff81aedadc>] paging_init+0x20/0x22
[    0.000000]  [<ffffffff81ae030d>] setup_arch+0x6f3/0x7c2
[    0.000000]  [<ffffffff81add806>] start_kernel+0x8f/0x2eb
[    0.000000]  [<ffffffff81add280>] x86_64_start_reservations+0x84/0x89
[    0.000000]  [<ffffffff81add377>] x86_64_start_kernel+0xf2/0xf9
[    0.000000] ---[ end trace d76bed13a5793ee5 ]---
[    0.000000] On node 3 totalpages: 4194304
[    0.000000]   Normal zone: 65536 pages used for memmap
[    0.000000]   Normal zone: 4128768 pages, LIFO batch:31

-- 
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551

[-- Attachment #2: config.gz --]
[-- Type: application/octet-stream, Size: 16242 bytes --]

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: WARNING: at mm/page_alloc.c:4514 free_area_init_node+0x4f/0x37b()
  2012-08-01 17:38 WARNING: at mm/page_alloc.c:4514 free_area_init_node+0x4f/0x37b() Borislav Petkov
@ 2012-08-01 23:33 ` Minchan Kim
  2012-08-02 11:06   ` Borislav Petkov
  0 siblings, 1 reply; 5+ messages in thread
From: Minchan Kim @ 2012-08-01 23:33 UTC (permalink / raw)
  To: Borislav Petkov
  Cc: Minchan Kim, Tejun Heo, Ralf Baechle, Andrew Morton,
	Linus Torvalds, LKML, linux-mm

Hello Borislav,

On Wed, Aug 01, 2012 at 07:38:37PM +0200, Borislav Petkov wrote:
> Hi,
> 
> I'm hitting the WARN_ON in $Subject with latest linus:
> v3.5-8833-g2d534926205d on a 4-node AMD system. As it looks from
> dmesg, it is happening on node 0, 1 and 2 but not on 3. Probably the
> pgdat->nr_zones thing but I'll have to add more dbg code to be sure.

As I look the code quickly, free_area_init_node initializes node_id and
node_start_pfn doublely. They were initialized by setup_node_data.

Could you test below patch? It's not a totally right way to fix it but
I want to confirm why it happens.

(I'm on vacation now so please understand that it hard to reach me)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 889532b..009ac28 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4511,7 +4511,7 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
        pg_data_t *pgdat = NODE_DATA(nid);
 
        /* pg_data_t should be reset to zero when it's allocated */
-       WARN_ON(pgdat->nr_zones || pgdat->node_start_pfn || pgdat->classzone_idx);
+       WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
 
        pgdat->node_id = nid;
        pgdat->node_start_pfn = node_start_pfn;

> 
> Config is attached.
> 
> dmesg:
> 
> [    0.000000] Early memory node ranges
> [    0.000000]   node   0: [mem 0x00010000-0x00087fff]
> [    0.000000]   node   0: [mem 0x00100000-0xc7ebffff]
> [    0.000000]   node   0: [mem 0x100000000-0x437ffffff]
> [    0.000000]   node   1: [mem 0x438000000-0x837ffffff]
> [    0.000000]   node   2: [mem 0x838000000-0xc37ffffff]
> [    0.000000]   node   3: [mem 0xc38000000-0x1037ffffff]
> [    0.000000] On node 0 totalpages: 4193848
> [    0.000000]   DMA zone: 64 pages used for memmap
> [    0.000000]   DMA zone: 6 pages reserved
> [    0.000000]   DMA zone: 3890 pages, LIFO batch:0
> [    0.000000]   DMA32 zone: 16320 pages used for memmap
> [    0.000000]   DMA32 zone: 798464 pages, LIFO batch:31
> [    0.000000]   Normal zone: 52736 pages used for memmap
> [    0.000000]   Normal zone: 3322368 pages, LIFO batch:31
> [    0.000000] ------------[ cut here ]------------
> [    0.000000] WARNING: at mm/page_alloc.c:4514 free_area_init_node+0x4f/0x37b()
> [    0.000000] Hardware name: Dinar
> [    0.000000] Modules linked in:
> [    0.000000] Pid: 0, comm: swapper Not tainted 3.5.0+ #9
> [    0.000000] Call Trace:
> [    0.000000]  [<ffffffff810320bd>] warn_slowpath_common+0x85/0x9d
> [    0.000000]  [<ffffffff810320ef>] warn_slowpath_null+0x1a/0x1c
> [    0.000000]  [<ffffffff81470bc0>] free_area_init_node+0x4f/0x37b
> [    0.000000]  [<ffffffff81af5962>] ? find_min_pfn_for_node+0x57/0x84
> [    0.000000]  [<ffffffff81af61a2>] free_area_init_nodes+0x55d/0x5ac
> [    0.000000]  [<ffffffff81aed7ca>] zone_sizes_init+0x3b/0x3d
> [    0.000000]  [<ffffffff81aedadc>] paging_init+0x20/0x22
> [    0.000000]  [<ffffffff81ae030d>] setup_arch+0x6f3/0x7c2
> [    0.000000]  [<ffffffff81add806>] start_kernel+0x8f/0x2eb
> [    0.000000]  [<ffffffff81add280>] x86_64_start_reservations+0x84/0x89
> [    0.000000]  [<ffffffff81add377>] x86_64_start_kernel+0xf2/0xf9
> [    0.000000] ---[ end trace d76bed13a5793ee3 ]---
> [    0.000000] On node 1 totalpages: 4194304
> [    0.000000]   Normal zone: 65536 pages used for memmap
> [    0.000000]   Normal zone: 4128768 pages, LIFO batch:31
> [    0.000000] ------------[ cut here ]------------
> [    0.000000] WARNING: at mm/page_alloc.c:4514 free_area_init_node+0x4f/0x37b()
> [    0.000000] Hardware name: Dinar
> [    0.000000] Modules linked in:
> [    0.000000] Pid: 0, comm: swapper Tainted: G        W    3.5.0+ #9
> [    0.000000] Call Trace:
> [    0.000000]  [<ffffffff810320bd>] warn_slowpath_common+0x85/0x9d
> [    0.000000]  [<ffffffff810320ef>] warn_slowpath_null+0x1a/0x1c
> [    0.000000]  [<ffffffff81470bc0>] free_area_init_node+0x4f/0x37b
> [    0.000000]  [<ffffffff81af5962>] ? find_min_pfn_for_node+0x57/0x84
> [    0.000000]  [<ffffffff81af61a2>] free_area_init_nodes+0x55d/0x5ac
> [    0.000000]  [<ffffffff81aed7ca>] zone_sizes_init+0x3b/0x3d
> [    0.000000]  [<ffffffff81aedadc>] paging_init+0x20/0x22
> [    0.000000]  [<ffffffff81ae030d>] setup_arch+0x6f3/0x7c2
> [    0.000000]  [<ffffffff81add806>] start_kernel+0x8f/0x2eb
> [    0.000000]  [<ffffffff81add280>] x86_64_start_reservations+0x84/0x89
> [    0.000000]  [<ffffffff81add377>] x86_64_start_kernel+0xf2/0xf9
> [    0.000000] ---[ end trace d76bed13a5793ee4 ]---
> [    0.000000] On node 2 totalpages: 4194304
> [    0.000000]   Normal zone: 65536 pages used for memmap
> [    0.000000]   Normal zone: 4128768 pages, LIFO batch:31
> [    0.000000] ------------[ cut here ]------------
> [    0.000000] WARNING: at mm/page_alloc.c:4514 free_area_init_node+0x4f/0x37b()
> [    0.000000] Hardware name: Dinar
> [    0.000000] Modules linked in:
> [    0.000000] Pid: 0, comm: swapper Tainted: G        W    3.5.0+ #9
> [    0.000000] Call Trace:
> [    0.000000]  [<ffffffff810320bd>] warn_slowpath_common+0x85/0x9d
> [    0.000000]  [<ffffffff810320ef>] warn_slowpath_null+0x1a/0x1c
> [    0.000000]  [<ffffffff81470bc0>] free_area_init_node+0x4f/0x37b
> [    0.000000]  [<ffffffff81af5962>] ? find_min_pfn_for_node+0x57/0x84
> [    0.000000]  [<ffffffff81af61a2>] free_area_init_nodes+0x55d/0x5ac
> [    0.000000]  [<ffffffff81aed7ca>] zone_sizes_init+0x3b/0x3d
> [    0.000000]  [<ffffffff81aedadc>] paging_init+0x20/0x22
> [    0.000000]  [<ffffffff81ae030d>] setup_arch+0x6f3/0x7c2
> [    0.000000]  [<ffffffff81add806>] start_kernel+0x8f/0x2eb
> [    0.000000]  [<ffffffff81add280>] x86_64_start_reservations+0x84/0x89
> [    0.000000]  [<ffffffff81add377>] x86_64_start_kernel+0xf2/0xf9
> [    0.000000] ---[ end trace d76bed13a5793ee5 ]---
> [    0.000000] On node 3 totalpages: 4194304
> [    0.000000]   Normal zone: 65536 pages used for memmap
> [    0.000000]   Normal zone: 4128768 pages, LIFO batch:31
> 
> -- 
> Regards/Gruss,
> Boris.
> 
> Advanced Micro Devices GmbH
> Einsteinring 24, 85609 Dornach
> GM: Alberto Bozzo
> Reg: Dornach, Landkreis Muenchen
> HRB Nr. 43632 WEEE Registernr: 129 19551


--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: WARNING: at mm/page_alloc.c:4514 free_area_init_node+0x4f/0x37b()
  2012-08-01 23:33 ` Minchan Kim
@ 2012-08-02 11:06   ` Borislav Petkov
  2012-08-06  0:01     ` Minchan Kim
  0 siblings, 1 reply; 5+ messages in thread
From: Borislav Petkov @ 2012-08-02 11:06 UTC (permalink / raw)
  To: Minchan Kim
  Cc: Tejun Heo, Ralf Baechle, Andrew Morton, Linus Torvalds, LKML,
	linux-mm

On Thu, Aug 02, 2012 at 08:33:35AM +0900, Minchan Kim wrote:
> Hello Borislav,
> 
> On Wed, Aug 01, 2012 at 07:38:37PM +0200, Borislav Petkov wrote:
> > Hi,
> > 
> > I'm hitting the WARN_ON in $Subject with latest linus:
> > v3.5-8833-g2d534926205d on a 4-node AMD system. As it looks from
> > dmesg, it is happening on node 0, 1 and 2 but not on 3. Probably the
> > pgdat->nr_zones thing but I'll have to add more dbg code to be sure.
> 
> As I look the code quickly, free_area_init_node initializes node_id and
> node_start_pfn doublely. They were initialized by setup_node_data.
> 
> Could you test below patch? It's not a totally right way to fix it but
> I want to confirm why it happens.
> 
> (I'm on vacation now so please understand that it hard to reach me)

I sincerely hope you're not going to interrupt your vacation because of
this.

:-).

> 
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 889532b..009ac28 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -4511,7 +4511,7 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
>         pg_data_t *pgdat = NODE_DATA(nid);
>  
>         /* pg_data_t should be reset to zero when it's allocated */
> -       WARN_ON(pgdat->nr_zones || pgdat->node_start_pfn || pgdat->classzone_idx);
> +       WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
>  
>         pgdat->node_id = nid;
>         pgdat->node_start_pfn = node_start_pfn;

Yep, you were right: ->node_start_pfn is set. I added additional debug
output for more info:

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 889532b8e6c1..c249abe4fee2 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4511,7 +4511,17 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
        pg_data_t *pgdat = NODE_DATA(nid);
 
        /* pg_data_t should be reset to zero when it's allocated */
-       WARN_ON(pgdat->nr_zones || pgdat->node_start_pfn || pgdat->classzone_idx);
+       WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
+
+       if (pgdat->node_start_pfn)
+               pr_warn("%s: pgdat->node_start_pfn: %lu\n", __func__, pgdat->node_start_pfn);
+
+       if (pgdat->nr_zones)
+               pr_warn("%s: pgdat->nr_zones: %d\n", __func__, pgdat->nr_zones);
+
+       if (pgdat->classzone_idx)
+               pr_warn("%s: pgdat->classzone_idx: %d\n", __func__, pgdat->classzone_idx);
+
 
        pgdat->node_id = nid;
        pgdat->node_start_pfn = node_start_pfn;



Here's what it says:

[    0.000000] On node 0 totalpages: 4193848
[    0.000000]   DMA zone: 64 pages used for memmap
[    0.000000]   DMA zone: 6 pages reserved
[    0.000000]   DMA zone: 3890 pages, LIFO batch:0
[    0.000000]   DMA32 zone: 16320 pages used for memmap
[    0.000000]   DMA32 zone: 798464 pages, LIFO batch:31
[    0.000000]   Normal zone: 52736 pages used for memmap
[    0.000000]   Normal zone: 3322368 pages, LIFO batch:31
[    0.000000] free_area_init_node: pgdat->node_start_pfn: 4423680	<----
[    0.000000] On node 1 totalpages: 4194304
[    0.000000]   Normal zone: 65536 pages used for memmap
[    0.000000]   Normal zone: 4128768 pages, LIFO batch:31
[    0.000000] free_area_init_node: pgdat->node_start_pfn: 8617984	<----
[    0.000000] On node 2 totalpages: 4194304
[    0.000000]   Normal zone: 65536 pages used for memmap
[    0.000000]   Normal zone: 4128768 pages, LIFO batch:31
[    0.000000] free_area_init_node: pgdat->node_start_pfn: 12812288	<----
[    0.000000] On node 3 totalpages: 4194304
[    0.000000]   Normal zone: 65536 pages used for memmap
[    0.000000]   Normal zone: 4128768 pages, LIFO batch:31
[    0.000000] ACPI: PM-Timer IO Port: 0x2008
[    0.000000] ACPI: Local APIC address 0xfee00000

Thanks.

-- 
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: WARNING: at mm/page_alloc.c:4514 free_area_init_node+0x4f/0x37b()
  2012-08-02 11:06   ` Borislav Petkov
@ 2012-08-06  0:01     ` Minchan Kim
  2012-08-08 13:50       ` Borislav Petkov
  0 siblings, 1 reply; 5+ messages in thread
From: Minchan Kim @ 2012-08-06  0:01 UTC (permalink / raw)
  To: Borislav Petkov
  Cc: Tejun Heo, Ralf Baechle, Andrew Morton, Linus Torvalds, LKML,
	linux-mm

Hi Borislav,

On Thu, Aug 02, 2012 at 01:06:41PM +0200, Borislav Petkov wrote:
> On Thu, Aug 02, 2012 at 08:33:35AM +0900, Minchan Kim wrote:
> > Hello Borislav,
> > 
> > On Wed, Aug 01, 2012 at 07:38:37PM +0200, Borislav Petkov wrote:
> > > Hi,
> > > 
> > > I'm hitting the WARN_ON in $Subject with latest linus:
> > > v3.5-8833-g2d534926205d on a 4-node AMD system. As it looks from
> > > dmesg, it is happening on node 0, 1 and 2 but not on 3. Probably the
> > > pgdat->nr_zones thing but I'll have to add more dbg code to be sure.
> > 
> > As I look the code quickly, free_area_init_node initializes node_id and
> > node_start_pfn doublely. They were initialized by setup_node_data.
> > 
> > Could you test below patch? It's not a totally right way to fix it but
> > I want to confirm why it happens.
> > 
> > (I'm on vacation now so please understand that it hard to reach me)
> 
> I sincerely hope you're not going to interrupt your vacation because of
> this.
> 
> :-).
> 
> > 
> > diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> > index 889532b..009ac28 100644
> > --- a/mm/page_alloc.c
> > +++ b/mm/page_alloc.c
> > @@ -4511,7 +4511,7 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
> >         pg_data_t *pgdat = NODE_DATA(nid);
> >  
> >         /* pg_data_t should be reset to zero when it's allocated */
> > -       WARN_ON(pgdat->nr_zones || pgdat->node_start_pfn || pgdat->classzone_idx);
> > +       WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
> >  
> >         pgdat->node_id = nid;
> >         pgdat->node_start_pfn = node_start_pfn;
> 
> Yep, you were right: ->node_start_pfn is set. I added additional debug
> output for more info:
> 
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 889532b8e6c1..c249abe4fee2 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -4511,7 +4511,17 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
>         pg_data_t *pgdat = NODE_DATA(nid);
>  
>         /* pg_data_t should be reset to zero when it's allocated */
> -       WARN_ON(pgdat->nr_zones || pgdat->node_start_pfn || pgdat->classzone_idx);
> +       WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
> +
> +       if (pgdat->node_start_pfn)
> +               pr_warn("%s: pgdat->node_start_pfn: %lu\n", __func__, pgdat->node_start_pfn);
> +
> +       if (pgdat->nr_zones)
> +               pr_warn("%s: pgdat->nr_zones: %d\n", __func__, pgdat->nr_zones);
> +
> +       if (pgdat->classzone_idx)
> +               pr_warn("%s: pgdat->classzone_idx: %d\n", __func__, pgdat->classzone_idx);
> +
>  
>         pgdat->node_id = nid;
>         pgdat->node_start_pfn = node_start_pfn;
> 
> 
> 
> Here's what it says:
> 
> [    0.000000] On node 0 totalpages: 4193848
> [    0.000000]   DMA zone: 64 pages used for memmap
> [    0.000000]   DMA zone: 6 pages reserved
> [    0.000000]   DMA zone: 3890 pages, LIFO batch:0
> [    0.000000]   DMA32 zone: 16320 pages used for memmap
> [    0.000000]   DMA32 zone: 798464 pages, LIFO batch:31
> [    0.000000]   Normal zone: 52736 pages used for memmap
> [    0.000000]   Normal zone: 3322368 pages, LIFO batch:31
> [    0.000000] free_area_init_node: pgdat->node_start_pfn: 4423680	<----
> [    0.000000] On node 1 totalpages: 4194304
> [    0.000000]   Normal zone: 65536 pages used for memmap
> [    0.000000]   Normal zone: 4128768 pages, LIFO batch:31
> [    0.000000] free_area_init_node: pgdat->node_start_pfn: 8617984	<----
> [    0.000000] On node 2 totalpages: 4194304
> [    0.000000]   Normal zone: 65536 pages used for memmap
> [    0.000000]   Normal zone: 4128768 pages, LIFO batch:31
> [    0.000000] free_area_init_node: pgdat->node_start_pfn: 12812288	<----
> [    0.000000] On node 3 totalpages: 4194304
> [    0.000000]   Normal zone: 65536 pages used for memmap
> [    0.000000]   Normal zone: 4128768 pages, LIFO batch:31
> [    0.000000] ACPI: PM-Timer IO Port: 0x2008
> [    0.000000] ACPI: Local APIC address 0xfee00000
> 
> Thanks.

Thanks for looking at this!

As soon as I come back from vacation, I see this BUG carefully and think patch I sent
is good. The patch's goal is to detect for uninitialized pgdat structure
when it was allocated. So it checks some variables randomly but unfortunately,
pgdat's members like node_start_pfn are closely related to boot arch code
so some members could be used by arch code before reaching generic mm code.
It was a Tejun's concern and he was correct.

I think nr_zones and classzone_idx should be initialized by only generic MM code
during boot sequence, not memory hotplug so that patch would be okay.

Linus already applied the patch in rc-1 but he might need better changelog.
I am not sure I send this patch to whom, Linus or Andrew?
Anyway, Please use below if really need it.

Thanks!

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: WARNING: at mm/page_alloc.c:4514 free_area_init_node+0x4f/0x37b()
  2012-08-06  0:01     ` Minchan Kim
@ 2012-08-08 13:50       ` Borislav Petkov
  0 siblings, 0 replies; 5+ messages in thread
From: Borislav Petkov @ 2012-08-08 13:50 UTC (permalink / raw)
  To: Minchan Kim
  Cc: Tejun Heo, Ralf Baechle, Andrew Morton, Linus Torvalds, LKML,
	linux-mm

On Mon, Aug 06, 2012 at 09:01:57AM +0900, Minchan Kim wrote:
> Linus already applied the patch in rc-1 but he might need better changelog.
> I am not sure I send this patch to whom, Linus or Andrew?
> Anyway, Please use below if really need it.

Btw, I see Linus has already shut up the warning upstream:

commit 8783b6e2b2cb726f2734cf208d101f73ac1ba616
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Thu Aug 2 10:37:03 2012 -0700

    mm: remove node_start_pfn checking in new WARN_ON for now
...

So I guess all is well.

Thanks.

-- 
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
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GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
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^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2012-08-08 13:50 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-08-01 17:38 WARNING: at mm/page_alloc.c:4514 free_area_init_node+0x4f/0x37b() Borislav Petkov
2012-08-01 23:33 ` Minchan Kim
2012-08-02 11:06   ` Borislav Petkov
2012-08-06  0:01     ` Minchan Kim
2012-08-08 13:50       ` Borislav Petkov

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