of: return NUMA_NO_NODE from fallback of_node_to_nid()

Node 0 might be offline as well as any other numa node, in this case kernel cannot handle memory allocation and crashes.

Signed-off-by Konstantin Khlebnikov <[email protected]>

Fixes 0c3f061c195c ("of: implement of_node_to_nid as a weak function")

---
  drivers/of/base.c  |    2 +-
  include/linux/of.h |    5 ++++-
  2 files changed, 5 insertions(+), 2 deletions(-)

drivers/of/base.c +1 -1

index 8f165b112e03..51f4bd16e613 100644
@@ -89,7 +89,7 @@ EXPORT_SYMBOL(of_n_size_cells);
  #ifdef CONFIG_NUMA
  int __weak of_node_to_nid(struct device_node *np)
  {
-	return numa_node_id();
+	return NUMA_NO_NODE;
  }
  #endif
 

include/linux/of.h +4 -1

index dfde07e77a63..78a04ee85a9c 100644
@@ -623,7 +623,10 @@ static inline const char *of_prop_next_string(struct property *prop,
  #if defined(CONFIG_OF) && defined(CONFIG_NUMA)
  extern int of_node_to_nid(struct device_node *np);
  #else
-static inline int of_node_to_nid(struct device_node *device) { return 0; }
+static inline int of_node_to_nid(struct device_node *device)
+{
+	return NUMA_NO_NODE;
+}
  #endif
 
  static inline struct device_node *of_find_matching_node(

Quoted 2 lines · Konstantin Khlebnikov

Node 0 might be offline as well as any other numa node, in this case kernel cannot handle memory allocation and crashes.

Example:

[    0.027133] ------------[ cut here ]------------
[    0.027938] kernel BUG at include/linux/gfp.h:322!

Quoted 3 lines · Konstantin Khlebnikov

Quoted 2 lines · Konstantin Khlebnikov

Node 0 might be offline as well as any other numa node, in this case kernel cannot handle memory allocation and crashes.

Isn't the bug that numa_node_id() returned an offline node? That shouldn't happen.

#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
...
#ifndef numa_node_id
/* Returns the number of the current Node. */
static inline int numa_node_id(void)

{
        return raw_cpu_read(numa_node);
}

#endif
...
#else /* !CONFIG_USE_PERCPU_NUMA_NODE_ID */

/* Returns the number of the current Node. */
#ifndef numa_node_id
static inline int numa_node_id(void)

{
        return cpu_to_node(raw_smp_processor_id());
}

#endif
...

So that's either the per-cpu numa_node value, right? Or the result of cpu_to_node on the current processor.

Quoted 4 lines

Example:

[    0.027133] ------------[ cut here ]------------
[    0.027938] kernel BUG at include/linux/gfp.h:322!

This is

VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES || !node_online(nid));

in

alloc_pages_exact_node().

And based on the trace below, that's

__slab_alloc -> alloc

alloc_pages_exact_node

        <- alloc_slab_page
                <- allocate_slab
                        <- new_slab
                                <- new_slab_objects
                                        < __slab_alloc?

which is just passing the node value down, right? Which I think was from:

domain = kzalloc_node(sizeof(*domain) + (sizeof(unsigned int) * size),
GFP_KERNEL, of_node_to_nid(of_node));

?

What platform is this on, looks to be x86? qemu emulation of a pathological topology? What was the topology?

Note that there is a ton of code that seems to assume node 0 is online. I started working on removing this assumption myself and it just led down a rathole (on power, we always have node 0 online, even if it is memoryless and cpuless, as a result).

I am guessing this is just happening early in boot before the per-cpu areas are setup? That's why (I think) x86 has the early_cpu_to_node() function...

Or do you not have CONFIG_OF set? So isn't the only change necessary to the include file, and it should just return first_online_node rather than 0?

Ah and there's more of those node 0 assumptions :)

#define first_online_node 0
#define first_memory_node 0

if MAX_NUMODES == 1...

-Nish

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Quoted 2 lines · Nishanth Aravamudan

Quoted 1 line · Konstantin Khlebnikov

On 08.04.2015 19:59, Konstantin Khlebnikov wrote:

Quoted 5 lines

Quoted 2 lines

Quoted 2 lines

Node 0 might be offline as well as any other numa node, in this case kernel cannot handle memory allocation and crashes.

Isn't the bug that numa_node_id() returned an offline node? That shouldn't happen.

Offline node 0 came from static-inline copy of that function from of.h I've patched weak function for keeping consistency.

Quoted 54 lines

#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
...
#ifndef numa_node_id
/* Returns the number of the current Node. */
static inline int numa_node_id(void)

{
        return raw_cpu_read(numa_node);
}

#endif
...
#else /* !CONFIG_USE_PERCPU_NUMA_NODE_ID */

/* Returns the number of the current Node. */
#ifndef numa_node_id
static inline int numa_node_id(void)

{
        return cpu_to_node(raw_smp_processor_id());
}

#endif
...

So that's either the per-cpu numa_node value, right? Or the result of cpu_to_node on the current processor.

Quoted 4 lines

Example:

[    0.027133] ------------[ cut here ]------------
[    0.027938] kernel BUG at include/linux/gfp.h:322!

This is

VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES || !node_online(nid));

in

alloc_pages_exact_node().

And based on the trace below, that's

__slab_alloc -> alloc

alloc_pages_exact_node

        <- alloc_slab_page
                <- allocate_slab
                        <- new_slab
                                <- new_slab_objects
                                        < __slab_alloc?

which is just passing the node value down, right? Which I think was from:

domain = kzalloc_node(sizeof(*domain) + (sizeof(unsigned int) * size),
GFP_KERNEL, of_node_to_nid(of_node));

Quoted 5 lines

?

What platform is this on, looks to be x86? qemu emulation of a pathological topology? What was the topology?

qemu x86_64, 2 cpu, 2 numa nodes, all memory in second.

I've slightly patched it to allow that setup (in qemu hardcoded 1Mb
of memory connected to node 0) And i've found unrelated bug -- if numa node has less that 4Mb ram then kernel crashes even earlier because numa code ignores that node
but buddy allocator still tries to use that pages.

Quoted 9 lines

Note that there is a ton of code that seems to assume node 0 is online. I started working on removing this assumption myself and it just led down a rathole (on power, we always have node 0 online, even if it is memoryless and cpuless, as a result).

I am guessing this is just happening early in boot before the per-cpu areas are setup? That's why (I think) x86 has the early_cpu_to_node() function...

Quoted 5 lines

Or do you not have CONFIG_OF set? So isn't the only change necessary to the include file, and it should just return first_online_node rather than 0?

Ah and there's more of those node 0 assumptions :)

That was x86 where is no CONFIG_OF at all.

I don't know what's wrong with that machine but ACPI reports that cpus and memory from node 0 as connected to node 1 and everything seems worked fine until lates upgrade -- seems like buggy static-inline of_node_to_nid was intoduced in 3.13 but x86 ioapic uses it during early allocations only in since 3.17. Machine owner teells that 3.15 worked fine.

Quoted 7 lines · Konstantin Khlebnikov

Quoted 5 lines · Nishanth Aravamudan

Quoted 3 lines · Konstantin Khlebnikov

Quoted 2 lines · Konstantin Khlebnikov

Node 0 might be offline as well as any other numa node, in this case kernel cannot handle memory allocation and crashes.

Quoted 5 lines

Quoted 2 lines

Isn't the bug that numa_node_id() returned an offline node? That shouldn't happen.

Offline node 0 came from static-inline copy of that function from of.h I've patched weak function for keeping consistency.

Got it, that's not necessarily clear in the original commit message.

Quoted 58 lines

Quoted 58 lines

#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
...
#ifndef numa_node_id
/* Returns the number of the current Node. */
static inline int numa_node_id(void)

{
         return raw_cpu_read(numa_node);
}

#endif
...
#else /* !CONFIG_USE_PERCPU_NUMA_NODE_ID */

/* Returns the number of the current Node. */
#ifndef numa_node_id
static inline int numa_node_id(void)

{
         return cpu_to_node(raw_smp_processor_id());
}

#endif
...

So that's either the per-cpu numa_node value, right? Or the result of cpu_to_node on the current processor.

Quoted 4 lines

Example:

[    0.027133] ------------[ cut here ]------------
[    0.027938] kernel BUG at include/linux/gfp.h:322!

This is

VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES || !node_online(nid));

in

alloc_pages_exact_node().

And based on the trace below, that's

__slab_alloc -> alloc

alloc_pages_exact_node

         <- alloc_slab_page
                 <- allocate_slab
                         <- new_slab
                                 <- new_slab_objects
                                         < __slab_alloc?

which is just passing the node value down, right? Which I think was from:

domain = kzalloc_node(sizeof(*domain) + (sizeof(unsigned int) * size),
GFP_KERNEL, of_node_to_nid(of_node));

?

Quoted 4 lines

Quoted 2 lines

What platform is this on, looks to be x86? qemu emulation of a pathological topology? What was the topology?

qemu x86_64, 2 cpu, 2 numa nodes, all memory in second.

Ok, this worked before? That is, this is a regression?

Quoted 6 lines

I've slightly patched it to allow that setup (in qemu hardcoded 1Mb
of memory connected to node 0) And i've found unrelated bug -- if numa node has less that 4Mb ram then kernel crashes even earlier because numa code ignores that node
but buddy allocator still tries to use that pages.

So this isn't an actually supported topology by qemu?

Quoted 16 lines

Quoted 10 lines

Note that there is a ton of code that seems to assume node 0 is online. I started working on removing this assumption myself and it just led down a rathole (on power, we always have node 0 online, even if it is memoryless and cpuless, as a result).

I am guessing this is just happening early in boot before the per-cpu areas are setup? That's why (I think) x86 has the early_cpu_to_node() function...

Quoted 5 lines

Or do you not have CONFIG_OF set? So isn't the only change necessary to the include file, and it should just return first_online_node rather than 0?

Ah and there's more of those node 0 assumptions :)

Quoted 8 lines

That was x86 where is no CONFIG_OF at all.

I don't know what's wrong with that machine but ACPI reports that cpus and memory from node 0 as connected to node 1 and everything seems worked fine until lates upgrade -- seems like buggy static-inline of_node_to_nid was intoduced in 3.13 but x86 ioapic uses it during early allocations only in since 3.17. Machine owner teells that 3.15 worked fine.

So, this was a qemu emulation of this actual physical machine without a node 0?

As I mentioned, there are lots of node 0 assumptions through the kernel. You might run into more issues at runtime.

Quoted 8 lines · Tanisha Aravamudan

Quoted 7 lines · Konstantin Khlebnikov

Quoted 5 lines · Nishanth Aravamudan

Quoted 3 lines · Konstantin Khlebnikov

Quoted 2 lines · Konstantin Khlebnikov

Node 0 might be offline as well as any other numa node, in this case kernel cannot handle memory allocation and crashes.

Quoted 7 lines

Quoted 5 lines

Quoted 2 lines

Isn't the bug that numa_node_id() returned an offline node? That shouldn't happen.

Offline node 0 came from static-inline copy of that function from of.h I've patched weak function for keeping consistency.

Got it, that's not necessarily clear in the original commit message.

Sorry.

Quoted 61 lines

Quoted 61 lines

Quoted 60 lines

#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
...
#ifndef numa_node_id
/* Returns the number of the current Node. */
static inline int numa_node_id(void)

{
        return raw_cpu_read(numa_node);
}

#endif
...
#else /* !CONFIG_USE_PERCPU_NUMA_NODE_ID */

/* Returns the number of the current Node. */
#ifndef numa_node_id
static inline int numa_node_id(void)

{
        return cpu_to_node(raw_smp_processor_id());
}

#endif
...

So that's either the per-cpu numa_node value, right? Or the result of cpu_to_node on the current processor.

Quoted 4 lines

Example:

[    0.027133] ------------[ cut here ]------------
[    0.027938] kernel BUG at include/linux/gfp.h:322!

This is

VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES || !node_online(nid));

in

alloc_pages_exact_node().

And based on the trace below, that's

__slab_alloc -> alloc

alloc_pages_exact_node

        <- alloc_slab_page
                <- allocate_slab
                        <- new_slab
                                <- new_slab_objects
                                        < __slab_alloc?

which is just passing the node value down, right? Which I think was from:

domain = kzalloc_node(sizeof(*domain) + (sizeof(unsigned int) * size),
GFP_KERNEL, of_node_to_nid(of_node));

?

What platform is this on, looks to be x86? qemu emulation of a pathological topology? What was the topology?

Quoted 3 lines

Quoted 1 line

qemu x86_64, 2 cpu, 2 numa nodes, all memory in second.

Ok, this worked before? That is, this is a regression?

Seems like that worked before 3.17 where
bug was exposed by commit 44767bfaaed782d6d635ecbb13f3980041e6f33e (x86, irq: Enhance mp_register_ioapic() to support irqdomain) this is first usage of *irq_domain_add*() in x86.

Quoted 7 lines

Quoted 5 lines

I've slightly patched it to allow that setup (in qemu hardcoded 1Mb
of memory connected to node 0) And i've found unrelated bug -- if numa node has less that 4Mb ram then kernel crashes even earlier because numa code ignores that node
but buddy allocator still tries to use that pages.

So this isn't an actually supported topology by qemu?

Qemu easily created memoryless numa nodes but node 0 have hardcoded 1Mb of ram. This seems like legacy prop for DOS era software.

Quoted 24 lines

Quoted 15 lines

Quoted 9 lines

Note that there is a ton of code that seems to assume node 0 is online. I started working on removing this assumption myself and it just led down a rathole (on power, we always have node 0 online, even if it is memoryless and cpuless, as a result).

I am guessing this is just happening early in boot before the per-cpu areas are setup? That's why (I think) x86 has the early_cpu_to_node() function...

Quoted 5 lines

Or do you not have CONFIG_OF set? So isn't the only change necessary to the include file, and it should just return first_online_node rather than 0?

Ah and there's more of those node 0 assumptions :)

Quoted 8 lines

That was x86 where is no CONFIG_OF at all.

I don't know what's wrong with that machine but ACPI reports that cpus and memory from node 0 as connected to node 1 and everything seems worked fine until lates upgrade -- seems like buggy static-inline of_node_to_nid was intoduced in 3.13 but x86 ioapic uses it during early allocations only in since 3.17. Machine owner teells that 3.15 worked fine.

Quoted 2 lines

So, this was a qemu emulation of this actual physical machine without a node 0?

Yep. Also I have crash from real machine but that stacktrace is messy because CONFIG_DEBUG_VM wasn't enabled and kernel crashed inside buddy allocator when tried to touch unallocated numa node structure.

Quoted 3 lines

As I mentioned, there are lots of node 0 assumptions through the kernel. You might run into more issues at runtime.

I think it's possible to trigger kernel crash for any memoryless numa node (not just for 0) if some device (like ioapic in my case) points to it in its acpi tables. In runtime numa affinity configured by user usually validated by the kernel, while numbers from firmware might be used without proper validation.

Anyway seems like at least one x86 machines works fine without memory in node 0.

Quoted 3 lines · Konstantin Khlebnikov

Node 0 might be offline as well as any other numa node, in this case kernel cannot handle memory allocation and crashes.

Example:

[    0.027133] ------------[ cut here ]------------
[    0.027938] kernel BUG at include/linux/gfp.h:322!
[    0.028000] invalid opcode: 0000 [#1] SMP
[    0.028000] Modules linked in:
[    0.028000] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.0.0-rc7 #12
[    0.028000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014
[    0.028000] task: ffff88007d3f8000 ti: ffff88007d3dc000 task.ti:
ffff88007d3dc000
[    0.028000] RIP: 0010:[<ffffffff8118574c>]  [<ffffffff8118574c>]
new_slab+0x30c/0x3c0
[    0.028000] RSP: 0000:ffff88007d3dfc28  EFLAGS: 00010246
[    0.028000] RAX: 0000000000000000 RBX: ffff88007d001800 RCX:
0000000000000001
[    0.028000] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
00000000002012d0
[    0.028000] RBP: ffff88007d3dfc58 R08: 0000000000000000 R09:
0000000000000000
[    0.028000] R10: 0000000000000001 R11: ffff88007d02fe40 R12:
00000000000000d0
[    0.028000] R13: 00000000000000c0 R14: 0000000000000015 R15:
0000000000000000
[    0.028000] FS:  0000000000000000(0000) GS:ffff88007fc00000(0000)
knlGS:0000000000000000
[    0.028000] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[    0.028000] CR2: 00000000ffffffff CR3: 0000000001e0e000 CR4:
00000000000006f0
[    0.028000] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[    0.028000] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[    0.028000] Stack:
[    0.028000]  0000000000000000 ffff88007fc175d0 ffffea0001f40bc0
00000000000000c0
[    0.028000]  ffff88007d001800 00000000000080d0 ffff88007d3dfd48
ffffffff8192da27
[    0.028000]  000000000000000d ffffffff81e27038 0000000000000000
0000000000000000
[    0.028000] Call Trace:
[    0.028000]  [<ffffffff8192da27>] __slab_alloc+0x3df/0x55d
[    0.028000]  [<ffffffff8109a92b>] ? __lock_acquire+0xc1b/0x1f40
[    0.028000]  [<ffffffff810b1f2c>] ? __irq_domain_add+0x3c/0xe0
[    0.028000]  [<ffffffff810998f5>] ? trace_hardirqs_on_caller+0x105/0x1d0
[    0.028000]  [<ffffffff813631ab>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[    0.028000]  [<ffffffff811890ab>] __kmalloc_node+0xab/0x210
[    0.028000]  [<ffffffff810394df>] ? ioapic_read_entry+0x1f/0x50
[    0.028000]  [<ffffffff810b1f2c>] ? __irq_domain_add+0x3c/0xe0
[    0.028000]  [<ffffffff810b1f2c>] __irq_domain_add+0x3c/0xe0
[    0.028000]  [<ffffffff81039e0e>] mp_irqdomain_create+0x9e/0x120
[    0.028000]  [<ffffffff81f22d49>] setup_IO_APIC+0x6b/0x798
[    0.028000]  [<ffffffff810398a5>] ? clear_IO_APIC+0x45/0x70
[    0.028000]  [<ffffffff81f21f01>] apic_bsp_setup+0x87/0x96
[    0.028000]  [<ffffffff81f1fdb4>] native_smp_prepare_cpus+0x237/0x275
[    0.028000]  [<ffffffff81f131b7>] kernel_init_freeable+0x120/0x265
[    0.028000]  [<ffffffff819271f9>] ? kernel_init+0x9/0xf0
[    0.028000]  [<ffffffff819271f0>] ? rest_init+0x130/0x130
[    0.028000]  [<ffffffff819271f9>] kernel_init+0x9/0xf0

[    0.028000]  [<ffffffff8193b958>] ret_from_fork+0x58/0x90
[    0.028000]  [<ffffffff819271f0>] ? rest_init+0x130/0x130
[    0.028000] Code: 6b b6 ff ff 49 89 c5 e9 ce fd ff ff 31 c0 90 e9 74 ff
ff ff 49 c7 04 04 00 00 00 00 e9 05 ff ff ff 4c 89 e7 ff d0 e9 d9 fe ff ff
<0f> 0b 4c 8b 73 38 44 89 e7 81 cf 00 00 20 00 4c 89 f6 48 c1 ee
[    0.028000] RIP  [<ffffffff8118574c>] new_slab+0x30c/0x3c0
[    0.028000]  RSP <ffff88007d3dfc28>
[    0.028039] ---[ end trace f03690e70d7e4be6 ]---

Hi Konstantin,

Quoted 65 lines · Konstantin Khlebnikov

Quoted 3 lines · Konstantin Khlebnikov

Node 0 might be offline as well as any other numa node, in this case kernel cannot handle memory allocation and crashes.

Example:

[    0.027133] ------------[ cut here ]------------
[    0.027938] kernel BUG at include/linux/gfp.h:322!
[    0.028000] invalid opcode: 0000 [#1] SMP
[    0.028000] Modules linked in:
[    0.028000] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.0.0-rc7 #12
[    0.028000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014
[    0.028000] task: ffff88007d3f8000 ti: ffff88007d3dc000 task.ti:
ffff88007d3dc000
[    0.028000] RIP: 0010:[<ffffffff8118574c>]  [<ffffffff8118574c>]
new_slab+0x30c/0x3c0
[    0.028000] RSP: 0000:ffff88007d3dfc28  EFLAGS: 00010246
[    0.028000] RAX: 0000000000000000 RBX: ffff88007d001800 RCX:
0000000000000001
[    0.028000] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
00000000002012d0
[    0.028000] RBP: ffff88007d3dfc58 R08: 0000000000000000 R09:
0000000000000000
[    0.028000] R10: 0000000000000001 R11: ffff88007d02fe40 R12:
00000000000000d0
[    0.028000] R13: 00000000000000c0 R14: 0000000000000015 R15:
0000000000000000
[    0.028000] FS:  0000000000000000(0000) GS:ffff88007fc00000(0000)
knlGS:0000000000000000
[    0.028000] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[    0.028000] CR2: 00000000ffffffff CR3: 0000000001e0e000 CR4:
00000000000006f0
[    0.028000] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[    0.028000] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[    0.028000] Stack:
[    0.028000]  0000000000000000 ffff88007fc175d0 ffffea0001f40bc0
00000000000000c0
[    0.028000]  ffff88007d001800 00000000000080d0 ffff88007d3dfd48
ffffffff8192da27
[    0.028000]  000000000000000d ffffffff81e27038 0000000000000000
0000000000000000
[    0.028000] Call Trace:
[    0.028000]  [<ffffffff8192da27>] __slab_alloc+0x3df/0x55d
[    0.028000]  [<ffffffff8109a92b>] ? __lock_acquire+0xc1b/0x1f40
[    0.028000]  [<ffffffff810b1f2c>] ? __irq_domain_add+0x3c/0xe0
[    0.028000]  [<ffffffff810998f5>] ? trace_hardirqs_on_caller+0x105/0x1d0
[    0.028000]  [<ffffffff813631ab>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[    0.028000]  [<ffffffff811890ab>] __kmalloc_node+0xab/0x210
[    0.028000]  [<ffffffff810394df>] ? ioapic_read_entry+0x1f/0x50
[    0.028000]  [<ffffffff810b1f2c>] ? __irq_domain_add+0x3c/0xe0
[    0.028000]  [<ffffffff810b1f2c>] __irq_domain_add+0x3c/0xe0
[    0.028000]  [<ffffffff81039e0e>] mp_irqdomain_create+0x9e/0x120
[    0.028000]  [<ffffffff81f22d49>] setup_IO_APIC+0x6b/0x798
[    0.028000]  [<ffffffff810398a5>] ? clear_IO_APIC+0x45/0x70
[    0.028000]  [<ffffffff81f21f01>] apic_bsp_setup+0x87/0x96
[    0.028000]  [<ffffffff81f1fdb4>] native_smp_prepare_cpus+0x237/0x275
[    0.028000]  [<ffffffff81f131b7>] kernel_init_freeable+0x120/0x265
[    0.028000]  [<ffffffff819271f9>] ? kernel_init+0x9/0xf0
[    0.028000]  [<ffffffff819271f0>] ? rest_init+0x130/0x130
[    0.028000]  [<ffffffff819271f9>] kernel_init+0x9/0xf0

Quoted 8 lines

[    0.028000]  [<ffffffff8193b958>] ret_from_fork+0x58/0x90
[    0.028000]  [<ffffffff819271f0>] ? rest_init+0x130/0x130
[    0.028000] Code: 6b b6 ff ff 49 89 c5 e9 ce fd ff ff 31 c0 90 e9 74 ff
ff ff 49 c7 04 04 00 00 00 00 e9 05 ff ff ff 4c 89 e7 ff d0 e9 d9 fe ff ff
<0f> 0b 4c 8b 73 38 44 89 e7 81 cf 00 00 20 00 4c 89 f6 48 c1 ee
[    0.028000] RIP  [<ffffffff8118574c>] new_slab+0x30c/0x3c0
[    0.028000]  RSP <ffff88007d3dfc28>
[    0.028039] ---[ end trace f03690e70d7e4be6 ]---

Shouldn't this be in the commit message?

Thanks,

--
Julian Calaby

Email: [email protected]
Profile: http://www.google.com/profiles/julian.calaby/

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Node 0 might be offline as well as any other numa node, in this case kernel cannot handle memory allocation and crashes.

Signed-off-by Konstantin Khlebnikov <[email protected]>

Fixes 0c3f061c195c ("of: implement of_node_to_nid as a weak function")

---
 drivers/of/base.c  |    2 +-
 include/linux/of.h |    5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

drivers/of/base.c +0 -0

index 8f165b112e03..51f4bd16e613 100644

drivers/of/base.c +0 -0

 }
 #endif
 

include/linux/of.h +4 -2

index dfde07e77a63..78a04ee85a9c 100644
@@ -623,7 +623,10 @@ static inline const char *of_prop_next_string(struct property *prop,
 #if defined(CONFIG_OF) && defined(CONFIG_NUMA)
 extern int of_node_to_nid(struct device_node *np);
 #else
-static inline int of_node_to_nid(struct device_node *device) { return 0; }
+static inline int of_node_to_nid(struct device_node *device)
+{
+       return NUMA_NO_NODE;
+}
 #endif
 
 static inline struct device_node *of_find_matching_node(
 
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Quoted 10 lines · Konstantin Khlebnikov

Node 0 might be offline as well as any other numa node, in this case kernel cannot handle memory allocation and crashes.

Signed-off-by Konstantin Khlebnikov <[email protected]>

Fixes 0c3f061c195c ("of: implement of_node_to_nid as a weak function")

---
  drivers/of/base.c  |    2 +-
  include/linux/of.h |    5 ++++-
  2 files changed, 5 insertions(+), 2 deletions(-)

drivers/of/base.c EXPORT_SYMBOL(of_n_size_cells); · line 92

Quoted 10 lines

drivers/of/base.c +1 -1

index 8f165b112e03..51f4bd16e613 100644
@@ -89,7 +89,7 @@ EXPORT_SYMBOL(of_n_size_cells);
  #ifdef CONFIG_NUMA
  int __weak of_node_to_nid(struct device_node *np)
  {
-       return numa_node_id();
+       return NUMA_NO_NODE;

This is going to break any NUMA machine that enables OF and expects the weak function to work.

Rob

Quoted 24 lines

drivers/of/base.c +0 -0

  }
  #endif
 

include/linux/of.h +4 -2

index dfde07e77a63..78a04ee85a9c 100644
@@ -623,7 +623,10 @@ static inline const char *of_prop_next_string(struct property *prop,
  #if defined(CONFIG_OF) && defined(CONFIG_NUMA)
  extern int of_node_to_nid(struct device_node *np);
  #else
-static inline int of_node_to_nid(struct device_node *device) { return 0; }
+static inline int of_node_to_nid(struct device_node *device)
+{
+       return NUMA_NO_NODE;
+}
  #endif
 
  static inline struct device_node *of_find_matching_node(
 
--

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Quoted 14 lines · Rob Herring

Quoted 11 lines · Konstantin Khlebnikov

Node 0 might be offline as well as any other numa node, in this case kernel cannot handle memory allocation and crashes.

Signed-off-by Konstantin Khlebnikov <[email protected]>

Fixes 0c3f061c195c ("of: implement of_node_to_nid as a weak function")

---
  drivers/of/base.c  |    2 +-
  include/linux/of.h |    5 ++++-
  2 files changed, 5 insertions(+), 2 deletions(-)

Quoted 14 lines

drivers/of/base.c EXPORT_SYMBOL(of_n_size_cells); · line 92

Quoted 10 lines

drivers/of/base.c +1 -1

index 8f165b112e03..51f4bd16e613 100644
@@ -89,7 +89,7 @@ EXPORT_SYMBOL(of_n_size_cells);
  #ifdef CONFIG_NUMA
  int __weak of_node_to_nid(struct device_node *np)
  {
-       return numa_node_id();
+       return NUMA_NO_NODE;

This is going to break any NUMA machine that enables OF and expects the weak function to work.

Why? NUMA_NO_NODE == -1 -- this's standard "no-affinity" signal. As I see powerpc/sparc versions of of_node_to_nid returns -1 if they cannot find out which node should be used.

Quoted 14 lines · Rob Herring

Quoted 11 lines · Konstantin Khlebnikov

Node 0 might be offline as well as any other numa node, in this case kernel cannot handle memory allocation and crashes.

Signed-off-by Konstantin Khlebnikov <[email protected]>

Fixes 0c3f061c195c ("of: implement of_node_to_nid as a weak function")

---
  drivers/of/base.c  |    2 +-
  include/linux/of.h |    5 ++++-
  2 files changed, 5 insertions(+), 2 deletions(-)

Quoted 14 lines

drivers/of/base.c EXPORT_SYMBOL(of_n_size_cells); · line 92

Quoted 10 lines

drivers/of/base.c +1 -1

index 8f165b112e03..51f4bd16e613 100644
@@ -89,7 +89,7 @@ EXPORT_SYMBOL(of_n_size_cells);
  #ifdef CONFIG_NUMA
  int __weak of_node_to_nid(struct device_node *np)
  {
-       return numa_node_id();
+       return NUMA_NO_NODE;

This is going to break any NUMA machine that enables OF and expects the weak function to work.

Why? NUMA_NO_NODE == -1 -- this's standard "no-affinity" signal. As I see powerpc/sparc versions of of_node_to_nid returns -1 if they cannot find out which node should be used.

When we test the cpu and memory hotplug feature in the server with x86 architecture and kernel4.0-rc4,we met the similar problem.

The situation is that when memory in node0 is offline,the system is down during booting.

Following is the bug information:

[    0.335176] BUG: unable to handle kernel paging request at
0000000000001b08
[    0.342164] IP: [<ffffffff81182587>] __alloc_pages_nodemask+0xb7/0x940
[    0.348706] PGD 0
[    0.350735] Oops: 0000 [#1] SMP
[ 0.353993] Modules linked in:
[    0.357063] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.0.0-rc4 #1
[    0.363232] Hardware name: Inspur TS860/TS860, BIOS TS860_2.0.0
2015/03/24
[    0.370095] task: ffff88085b1e0000 ti: ffff88085b1e8000 task.ti:
ffff88085b1e8000
[    0.377564] RIP: 0010:[<ffffffff81182587>]  [<ffffffff81182587>]
__alloc_pages_nodemask+0xb7/0x940
[    0.386524] RSP: 0000:ffff88085b1ebac8  EFLAGS: 00010246
[    0.391828] RAX: 0000000000001b00 RBX: 0000000000000010 RCX:
0000000000000000
[    0.398953] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
00000000002052d0
[    0.406075] RBP: ffff88085b1ebbb8 R08: ffff88085b13fec0 R09:
000000005b13fe01
[    0.413198] R10: ffff88085e807300 R11: ffffffff810d4bc1 R12:
000000000001002a
[    0.420321] R13: 00000000002052d0 R14: 0000000000000001 R15:
00000000000040d0
[    0.427446] FS: 0000000000000000(0000) GS:ffff88085ee00000(0000)
knlGS:0000000000000000
[    0.435522] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.441259] CR2: 0000000000001b08 CR3: 00000000019ae000 CR4:
00000000001406f0
[    0.448382] Stack:
[ 0.450392]  ffff88085b1e0000 0000000000000400 ffff88085b1effff
ffff88085b1ebb68
[    0.457846]  000000000000007b ffff88085b12d140 ffff88085b249000
000000000000007b
[ 0.465298]  ffff88085b1ebb28 ffffffff81af2900 0000000000000000
002052d05b12d140
[    0.472750] Call Trace:
[    0.475206]  [<ffffffff811d27b3>] ? deactivate_slab+0x383/0x400
[    0.481123] [<ffffffff811d3947>] new_slab+0xa7/0x460
[ 0.486174]  [<ffffffff816789e5>] __slab_alloc+0x310/0x470
[    0.491655] [<ffffffff8105304f>] ? dmar_msi_set_affinity+0x8f/0xc0
[    0.497921] [<ffffffff810d4bc1>] ? __irq_domain_add+0x41/0x100
[ 0.503838]  [<ffffffff810d0fee>] ? irq_do_set_affinity+0x5e/0x70
[    0.509920] [<ffffffff811d571d>] __kmalloc_node+0xad/0x2e0
[ 0.515483]  [<ffffffff810d4bc1>] ? __irq_domain_add+0x41/0x100
[    0.521392] [<ffffffff810d4bc1>] __irq_domain_add+0x41/0x100
[ 0.527133]  [<ffffffff8105102e>] mp_irqdomain_create+0x9e/0x120
[    0.533140] [<ffffffff81b2fb14>] setup_IO_APIC+0x64/0x1be
[ 0.538622]  [<ffffffff81b2e226>] apic_bsp_setup+0xa2/0xae
[    0.544099] [<ffffffff81b2bc70>] native_smp_prepare_cpus+0x267/0x2b2
[    0.550531] [<ffffffff81b1927b>] kernel_init_freeable+0xf2/0x253
[    0.556625] [<ffffffff8166b960>] ? rest_init+0x80/0x80
[ 0.561845]  [<ffffffff8166b96e>] kernel_init+0xe/0xf0
[    0.566979] [<ffffffff81681bd8>] ret_from_fork+0x58/0x90
[ 0.572374]  [<ffffffff8166b960>] ? rest_init+0x80/0x80
[    0.577591] Code: 30 97 00 89 45 bc 83 e1 0f b8 22 01 32 01 01 c9 d3
f8 83 e0 03 89 9d 6c ff ff ff 83 e3 10 89 45 c0 0f 85 6d 01 00 00 48 8b
45 88 <48> 83 78 08 00 0f 84 51 01 00 00 b8 01 00 00 00 44 89 f1 d3 e0
[    0.597537] RIP [<ffffffff81182587>] __alloc_pages_nodemask+0xb7/0x940
[    0.604158]  RSP <ffff88085b1ebac8>
[    0.607643] CR2: 0000000000001b08
[    0.610962] ---[ end trace 0a600c0841386992 ]---
[    0.615573] Kernel panic - not syncing: Fatal exception
[    0.620792] ---[ end Kernel panic - not syncing: Fatal exception

*From:* Rob Herring <mailto:[email protected]>
*Date:* 2015-04-14 00:49
*To:* Konstantin Khlebnikov <mailto:[email protected]>
*CC:* Grant Likely <mailto:[email protected]>; [email protected] <mailto:[email protected]>; Rob Herring <mailto:[email protected]>; [email protected] <mailto:[email protected]>; [email protected] <mailto:[email protected]>; [email protected] <mailto:[email protected]>; linuxppc-dev <mailto:linuxppc-dev-uLR06cmDAlY/[email protected]>
*Subject:* Re: [PATCH] of: return NUMA_NO_NODE from fallback
of_node_to_nid()

Quoted 31 lines · Konstantin Khlebnikov

Quoted 14 lines · Rob Herring

Quoted 11 lines · Konstantin Khlebnikov

Node 0 might be offline as well as any other numa node, in this case kernel cannot handle memory allocation and crashes.

Signed-off-by Konstantin Khlebnikov <[email protected]>

Fixes 0c3f061c195c ("of: implement of_node_to_nid as a weak function")

---
  drivers/of/base.c  |    2 +-
  include/linux/of.h |    5 ++++-
  2 files changed, 5 insertions(+), 2 deletions(-)

Quoted 14 lines

drivers/of/base.c EXPORT_SYMBOL(of_n_size_cells); · line 92

Quoted 10 lines

drivers/of/base.c +1 -1

index 8f165b112e03..51f4bd16e613 100644
@@ -89,7 +89,7 @@ EXPORT_SYMBOL(of_n_size_cells);
  #ifdef CONFIG_NUMA
  int __weak of_node_to_nid(struct device_node *np)
  {
-       return numa_node_id();
+       return NUMA_NO_NODE;

This is going to break any NUMA machine that enables OF and expects the weak function to work.

Quoted 3 lines

Why? NUMA_NO_NODE == -1 -- this's standard "no-affinity" signal. As I see powerpc/sparc versions of of_node_to_nid returns -1 if they cannot find out which node should be used.

Ah, I was thinking those platforms were relying on the default implementation. I guess any real NUMA support is going to need to override this function. The arm64 patch series does that as well. We need to be sure this change is correct for metag which appears to be the only other OF enabled platform with NUMA support.
In that case, then there is little reason to keep the inline and we can just always enable the weak function (with your change). It is slightly less optimal, but the few callers hardly appear to be hot paths.
Rob
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To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

When we test the cpu and memory hotplug feature in the server with x86 architecture and kernel4.0-rc4,we met the similar problem.

The situation is that when memory in node0 is offline,the system is down during booting.

Following is the bug information:

[    0.335176] BUG: unable to handle kernel paging request at
0000000000001b08
[    0.342164] IP: [<ffffffff81182587>] __alloc_pages_nodemask+0xb7/0x940
[    0.348706] PGD 0
[    0.350735] Oops: 0000 [#1] SMP
[ 0.353993] Modules linked in:
[    0.357063] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.0.0-rc4 #1
[    0.363232] Hardware name: Inspur TS860/TS860, BIOS TS860_2.0.0
2015/03/24
[    0.370095] task: ffff88085b1e0000 ti: ffff88085b1e8000 task.ti:
ffff88085b1e8000
[    0.377564] RIP: 0010:[<ffffffff81182587>]  [<ffffffff81182587>]
__alloc_pages_nodemask+0xb7/0x940
[    0.386524] RSP: 0000:ffff88085b1ebac8  EFLAGS: 00010246
[    0.391828] RAX: 0000000000001b00 RBX: 0000000000000010 RCX:
0000000000000000
[    0.398953] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
00000000002052d0
[    0.406075] RBP: ffff88085b1ebbb8 R08: ffff88085b13fec0 R09:
000000005b13fe01
[    0.413198] R10: ffff88085e807300 R11: ffffffff810d4bc1 R12:
000000000001002a
[    0.420321] R13: 00000000002052d0 R14: 0000000000000001 R15:
00000000000040d0
[    0.427446] FS: 0000000000000000(0000) GS:ffff88085ee00000(0000)
knlGS:0000000000000000
[    0.435522] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.441259] CR2: 0000000000001b08 CR3: 00000000019ae000 CR4:
00000000001406f0
[    0.448382] Stack:
[ 0.450392]  ffff88085b1e0000 0000000000000400 ffff88085b1effff
ffff88085b1ebb68
[    0.457846]  000000000000007b ffff88085b12d140 ffff88085b249000
000000000000007b
[ 0.465298]  ffff88085b1ebb28 ffffffff81af2900 0000000000000000
002052d05b12d140
[    0.472750] Call Trace:
[    0.475206]  [<ffffffff811d27b3>] ? deactivate_slab+0x383/0x400
[    0.481123] [<ffffffff811d3947>] new_slab+0xa7/0x460
[ 0.486174]  [<ffffffff816789e5>] __slab_alloc+0x310/0x470
[    0.491655] [<ffffffff8105304f>] ? dmar_msi_set_affinity+0x8f/0xc0
[    0.497921] [<ffffffff810d4bc1>] ? __irq_domain_add+0x41/0x100
[ 0.503838]  [<ffffffff810d0fee>] ? irq_do_set_affinity+0x5e/0x70
[    0.509920] [<ffffffff811d571d>] __kmalloc_node+0xad/0x2e0
[ 0.515483]  [<ffffffff810d4bc1>] ? __irq_domain_add+0x41/0x100
[    0.521392] [<ffffffff810d4bc1>] __irq_domain_add+0x41/0x100
[ 0.527133]  [<ffffffff8105102e>] mp_irqdomain_create+0x9e/0x120
[    0.533140] [<ffffffff81b2fb14>] setup_IO_APIC+0x64/0x1be
[ 0.538622]  [<ffffffff81b2e226>] apic_bsp_setup+0xa2/0xae
[    0.544099] [<ffffffff81b2bc70>] native_smp_prepare_cpus+0x267/0x2b2
[    0.550531] [<ffffffff81b1927b>] kernel_init_freeable+0xf2/0x253
[    0.556625] [<ffffffff8166b960>] ? rest_init+0x80/0x80
[ 0.561845]  [<ffffffff8166b96e>] kernel_init+0xe/0xf0
[    0.566979] [<ffffffff81681bd8>] ret_from_fork+0x58/0x90
[ 0.572374]  [<ffffffff8166b960>] ? rest_init+0x80/0x80
[    0.577591] Code: 30 97 00 89 45 bc 83 e1 0f b8 22 01 32 01 01 c9 d3
f8 83 e0 03 89 9d 6c ff ff ff 83 e3 10 89 45 c0 0f 85 6d 01 00 00 48 8b
45 88 <48> 83 78 08 00 0f 84 51 01 00 00 b8 01 00 00 00 44 89 f1 d3 e0
[    0.597537] RIP [<ffffffff81182587>] __alloc_pages_nodemask+0xb7/0x940
[    0.604158]  RSP <ffff88085b1ebac8>
[    0.607643] CR2: 0000000000001b08
[    0.610962] ---[ end trace 0a600c0841386992 ]---
[    0.615573] Kernel panic - not syncing: Fatal exception
[    0.620792] ---[ end Kernel panic - not syncing: Fatal exception

*From:* Rob Herring <mailto:[email protected]> *Date:* 2015-04-14 00:49
*To:* Konstantin Khlebnikov <mailto:[email protected]> *CC:* Grant Likely <mailto:[email protected]>; [email protected] <mailto:[email protected]>; Rob Herring <mailto:[email protected]>; [email protected] <mailto:[email protected]>; [email protected] <mailto:[email protected]>; [email protected] <mailto:[email protected]>; linuxppc-dev <mailto:[email protected]>
*Subject:* Re: [PATCH] of: return NUMA_NO_NODE from fallback of_node_to_nid()

Quoted 31 lines · Konstantin Khlebnikov

Quoted 14 lines · Rob Herring

Quoted 11 lines · Konstantin Khlebnikov

Node 0 might be offline as well as any other numa node, in this case kernel cannot handle memory allocation and crashes.

Signed-off-by Konstantin Khlebnikov <[email protected]>

Fixes 0c3f061c195c ("of: implement of_node_to_nid as a weak function")

---
  drivers/of/base.c  |    2 +-
  include/linux/of.h |    5 ++++-
  2 files changed, 5 insertions(+), 2 deletions(-)

Quoted 14 lines

drivers/of/base.c EXPORT_SYMBOL(of_n_size_cells); · line 92

Quoted 10 lines

drivers/of/base.c +1 -1

index 8f165b112e03..51f4bd16e613 100644
@@ -89,7 +89,7 @@ EXPORT_SYMBOL(of_n_size_cells);
  #ifdef CONFIG_NUMA
  int __weak of_node_to_nid(struct device_node *np)
  {
-       return numa_node_id();
+       return NUMA_NO_NODE;

This is going to break any NUMA machine that enables OF and expects the weak function to work.

Quoted 3 lines

Why? NUMA_NO_NODE == -1 -- this's standard "no-affinity" signal. As I see powerpc/sparc versions of of_node_to_nid returns -1 if they cannot find out which node should be used.

Ah, I was thinking those platforms were relying on the default implementation. I guess any real NUMA support is going to need to override this function. The arm64 patch series does that as well. We need to be sure this change is correct for metag which appears to be the only other OF enabled platform with NUMA support.
In that case, then there is little reason to keep the inline and we can just always enable the weak function (with your change). It is slightly less optimal, but the few callers hardly appear to be hot paths.
Rob
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To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected]
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Please read the FAQ at http://www.tux.org/lkml/

Quoted 31 lines · Konstantin Khlebnikov

Quoted 14 lines · Rob Herring

Quoted 11 lines · Konstantin Khlebnikov

Node 0 might be offline as well as any other numa node, in this case kernel cannot handle memory allocation and crashes.

Signed-off-by Konstantin Khlebnikov <[email protected]>

Fixes 0c3f061c195c ("of: implement of_node_to_nid as a weak function")

---
  drivers/of/base.c  |    2 +-
  include/linux/of.h |    5 ++++-
  2 files changed, 5 insertions(+), 2 deletions(-)

Quoted 14 lines

drivers/of/base.c EXPORT_SYMBOL(of_n_size_cells); · line 92

Quoted 10 lines

drivers/of/base.c +1 -1

index 8f165b112e03..51f4bd16e613 100644
@@ -89,7 +89,7 @@ EXPORT_SYMBOL(of_n_size_cells);
  #ifdef CONFIG_NUMA
  int __weak of_node_to_nid(struct device_node *np)
  {
-       return numa_node_id();
+       return NUMA_NO_NODE;

This is going to break any NUMA machine that enables OF and expects the weak function to work.

Quoted 3 lines

Why? NUMA_NO_NODE == -1 -- this's standard "no-affinity" signal. As I see powerpc/sparc versions of of_node_to_nid returns -1 if they cannot find out which node should be used.

Ah, I was thinking those platforms were relying on the default implementation. I guess any real NUMA support is going to need to override this function. The arm64 patch series does that as well. We need to be sure this change is correct for metag which appears to be the only other OF enabled platform with NUMA support.

In that case, then there is little reason to keep the inline and we can just always enable the weak function (with your change). It is slightly less optimal, but the few callers hardly appear to be hot paths.