2012-08-21 03:53:52

by Jianguo Wu

[permalink] [raw]
Subject: [PATCH] mm/ia64: fix a memory block size bug

From: Jianguo Wu <[email protected]>

Hi all,
I found following definition in include/linux/memory.h, in my IA64
platform, SECTION_SIZE_BITS is equal to 32, and MIN_MEMORY_BLOCK_SIZE will be 0.
#define MIN_MEMORY_BLOCK_SIZE (1 << SECTION_SIZE_BITS)

Because MIN_MEMORY_BLOCK_SIZE is 32bits, so MIN_MEMORY_BLOCK_SIZE(1 << 32)
will equal to 0. This will cause wrong system memory infomation in sysfs. I think
it should be:
#define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS)

linux-drf:/sys/devices/system/memory # ll
total 0
-r--r--r-- 1 root root 65536 Aug 20 02:35 block_size_bytes
drwxr-xr-x 3 root root 0 Aug 20 02:19 memory0
drwxr-xr-x 2 root root 0 Aug 20 02:35 power
-rw-r--r-- 1 root root 65536 Aug 20 02:35 uevent

linux-drf:/sys/devices/system/memory # cat block_size_bytes
0

linux-drf:/sys/devices/system/memory/memory0 # cat *
8000000000000000
cat: node0: Is a directory
cat: node1: Is a directory
cat: node2: Is a directory
cat: node3: Is a directory
0
8000000000000000
cat: power: Is a directory
1
online
cat: subsystem: Is a directory

And "echo offline > memory0/state" will cause following call trace:

kernel BUG at mm/memory_hotplug.c:885!
sh[6455]: bugcheck! 0 [1]

Pid: 6455, CPU 0, comm: sh
psr : 0000101008526030 ifs : 8000000000000fa4 ip : [<a0000001008c40f0>] Not tainted (3.6.0-rc1)
ip is at offline_pages+0x210/0xee0
unat: 0000000000000000 pfs : 0000000000000fa4 rsc : 0000000000000003
rnat: a0000001008f2d50 bsps: 0000000000000000 pr : 65519a96659a9565
ldrs: 0000000000000000 ccv : 0000010b9263f310 fpsr: 0009804c0270033f
csd : 0000000000000000 ssd : 0000000000000000
b0 : a0000001008c40f0 b6 : a000000100473980 b7 : a0000001000106d0
f6 : 000000000000000000000 f7 : 1003e0000000085c9354c
f8 : 1003e0044b82fa09b5a53 f9 : 1003e000000d65cd62abf
f10 : 1003efd02efdec682803d f11 : 1003e0000000000000042
r1 : a00000010152c2e0 r2 : 0000000000006ada r3 : 000000000000fffe
r8 : 0000000000000026 r9 : a00000010121cc18 r10 : a0000001013309f0
r11 : 65519a96659a19e9 r12 : e00000070a91fdf0 r13 : e00000070a910000
r14 : 0000000000006ada r15 : 0000000000004000 r16 : 000000006ad8356c
r17 : a0000001019a525e r18 : 0000000000007fff r19 : 0000000000000000
r20 : 0000000000006ad6 r21 : 0000000000006ad6 r22 : a00000010133bec8
r23 : 0000000000006ad4 r24 : 0000000000000002 r25 : 8200000000260038
r26 : 00000000000004f9 r27 : 00000000000004f8 r28 : 000000000001cf98
r29 : 0000000000000038 r30 : a0000001019a5ae0 r31 : 000000000001cf60

Call Trace:
[<a0000001000163e0>] show_stack+0x80/0xa0
sp=e00000070a91f9b0 bsp=e00000070a9115e0
[<a000000100016a40>] show_regs+0x640/0x920
sp=e00000070a91fb80 bsp=e00000070a911588
[<a000000100040590>] die+0x190/0x2c0
sp=e00000070a91fb90 bsp=e00000070a911548
[<a000000100040710>] die_if_kernel+0x50/0x80
sp=e00000070a91fb90 bsp=e00000070a911518
[<a0000001008f8030>] ia64_bad_break+0x3d0/0x6e0
sp=e00000070a91fb90 bsp=e00000070a9114f0
[<a00000010000c0c0>] ia64_native_leave_kernel+0x0/0x270
sp=e00000070a91fc20 bsp=e00000070a9114f0
[<a0000001008c40f0>] offline_pages+0x210/0xee0
sp=e00000070a91fdf0 bsp=e00000070a9113c8
[<a00000010022d580>] alloc_pages_current+0x180/0x2a0
sp=e00000070a91fe20 bsp=e00000070a9113a

This patch is trying to fix the bug.

Signed-off-by: Jianguo Wu <[email protected]>
---
include/linux/memory.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/include/linux/memory.h b/include/linux/memory.h
index 1ac7f6e..ff9a9f8 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -19,7 +19,7 @@
#include <linux/compiler.h>
#include <linux/mutex.h>

-#define MIN_MEMORY_BLOCK_SIZE (1 << SECTION_SIZE_BITS)
+#define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS)

struct memory_block {
unsigned long start_section_nr;
--
1.7.6.1




.



2012-08-23 15:48:33

by Michal Hocko

[permalink] [raw]
Subject: Re: [PATCH] mm/ia64: fix a memory block size bug

[Fixed gregkh email address]

On Tue 21-08-12 11:46:10, wujianguo wrote:
> From: Jianguo Wu <[email protected]>
>
> Hi all,
> I found following definition in include/linux/memory.h, in my IA64
> platform, SECTION_SIZE_BITS is equal to 32, and MIN_MEMORY_BLOCK_SIZE will be 0.
> #define MIN_MEMORY_BLOCK_SIZE (1 << SECTION_SIZE_BITS)

OK, so I assume you have CONFIG_FORCE_MAX_ZONEORDER 17 and PAGE_SHIFT
16, right? But even CONFIG_FORCE_MAX_ZONEORDER 16 would be a problem.

> Because MIN_MEMORY_BLOCK_SIZE is 32bits, so MIN_MEMORY_BLOCK_SIZE(1 << 32)
> will equal to 0. This will cause wrong system memory infomation in sysfs. I think
> it should be:
> #define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS)
>

I guess the part below is not necessary for the changelog

> linux-drf:/sys/devices/system/memory # ll
> total 0
> -r--r--r-- 1 root root 65536 Aug 20 02:35 block_size_bytes
> drwxr-xr-x 3 root root 0 Aug 20 02:19 memory0
> drwxr-xr-x 2 root root 0 Aug 20 02:35 power
> -rw-r--r-- 1 root root 65536 Aug 20 02:35 uevent
>
> linux-drf:/sys/devices/system/memory # cat block_size_bytes
> 0
>
> linux-drf:/sys/devices/system/memory/memory0 # cat *
> 8000000000000000
> cat: node0: Is a directory
> cat: node1: Is a directory
> cat: node2: Is a directory
> cat: node3: Is a directory
> 0
> 8000000000000000
> cat: power: Is a directory
> 1
> online
> cat: subsystem: Is a directory
>

Up to here.

> And "echo offline > memory0/state" will cause following call trace:
>
> kernel BUG at mm/memory_hotplug.c:885!
> sh[6455]: bugcheck! 0 [1]
>
> Pid: 6455, CPU 0, comm: sh
> psr : 0000101008526030 ifs : 8000000000000fa4 ip : [<a0000001008c40f0>] Not tainted (3.6.0-rc1)
> ip is at offline_pages+0x210/0xee0
> unat: 0000000000000000 pfs : 0000000000000fa4 rsc : 0000000000000003
> rnat: a0000001008f2d50 bsps: 0000000000000000 pr : 65519a96659a9565
> ldrs: 0000000000000000 ccv : 0000010b9263f310 fpsr: 0009804c0270033f
> csd : 0000000000000000 ssd : 0000000000000000
> b0 : a0000001008c40f0 b6 : a000000100473980 b7 : a0000001000106d0
> f6 : 000000000000000000000 f7 : 1003e0000000085c9354c
> f8 : 1003e0044b82fa09b5a53 f9 : 1003e000000d65cd62abf
> f10 : 1003efd02efdec682803d f11 : 1003e0000000000000042
> r1 : a00000010152c2e0 r2 : 0000000000006ada r3 : 000000000000fffe
> r8 : 0000000000000026 r9 : a00000010121cc18 r10 : a0000001013309f0
> r11 : 65519a96659a19e9 r12 : e00000070a91fdf0 r13 : e00000070a910000
> r14 : 0000000000006ada r15 : 0000000000004000 r16 : 000000006ad8356c
> r17 : a0000001019a525e r18 : 0000000000007fff r19 : 0000000000000000
> r20 : 0000000000006ad6 r21 : 0000000000006ad6 r22 : a00000010133bec8
> r23 : 0000000000006ad4 r24 : 0000000000000002 r25 : 8200000000260038
> r26 : 00000000000004f9 r27 : 00000000000004f8 r28 : 000000000001cf98
> r29 : 0000000000000038 r30 : a0000001019a5ae0 r31 : 000000000001cf60
>
> Call Trace:
> [<a0000001000163e0>] show_stack+0x80/0xa0
> sp=e00000070a91f9b0 bsp=e00000070a9115e0
> [<a000000100016a40>] show_regs+0x640/0x920
> sp=e00000070a91fb80 bsp=e00000070a911588
> [<a000000100040590>] die+0x190/0x2c0
> sp=e00000070a91fb90 bsp=e00000070a911548
> [<a000000100040710>] die_if_kernel+0x50/0x80
> sp=e00000070a91fb90 bsp=e00000070a911518
> [<a0000001008f8030>] ia64_bad_break+0x3d0/0x6e0
> sp=e00000070a91fb90 bsp=e00000070a9114f0
> [<a00000010000c0c0>] ia64_native_leave_kernel+0x0/0x270
> sp=e00000070a91fc20 bsp=e00000070a9114f0
> [<a0000001008c40f0>] offline_pages+0x210/0xee0
> sp=e00000070a91fdf0 bsp=e00000070a9113c8
> [<a00000010022d580>] alloc_pages_current+0x180/0x2a0
> sp=e00000070a91fe20 bsp=e00000070a9113a
>
> This patch is trying to fix the bug.

not just trying ;)

>
> Signed-off-by: Jianguo Wu <[email protected]>

Reviewed-by: Michal Hocko <[email protected]>

> ---
> include/linux/memory.h | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/include/linux/memory.h b/include/linux/memory.h
> index 1ac7f6e..ff9a9f8 100644
> --- a/include/linux/memory.h
> +++ b/include/linux/memory.h
> @@ -19,7 +19,7 @@
> #include <linux/compiler.h>
> #include <linux/mutex.h>
>
> -#define MIN_MEMORY_BLOCK_SIZE (1 << SECTION_SIZE_BITS)
> +#define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS)
>
> struct memory_block {
> unsigned long start_section_nr;

--
Michal Hocko
SUSE Labs

2012-08-24 02:38:47

by Jianguo Wu

[permalink] [raw]
Subject: Re: [PATCH] mm/ia64: fix a memory block size bug

Hi Michal,
Thanks for your comments and review.

On 2012-8-23 23:48, Michal Hocko wrote:
> [Fixed gregkh email address]
>
> On Tue 21-08-12 11:46:10, wujianguo wrote:
>> From: Jianguo Wu <[email protected]>
>>
>> Hi all,
>> I found following definition in include/linux/memory.h, in my IA64
>> platform, SECTION_SIZE_BITS is equal to 32, and MIN_MEMORY_BLOCK_SIZE will be 0.
>> #define MIN_MEMORY_BLOCK_SIZE (1 << SECTION_SIZE_BITS)
>
> OK, so I assume you have CONFIG_FORCE_MAX_ZONEORDER 17 and PAGE_SHIFT
> 16, right? But even CONFIG_FORCE_MAX_ZONEORDER 16 would be a problem.
>

Yes, you are right, CONFIG_FORCE_MAX_ZONEORDER 16 would be a problem too.

>> Because MIN_MEMORY_BLOCK_SIZE is 32bits, so MIN_MEMORY_BLOCK_SIZE(1 << 32)
>> will equal to 0. This will cause wrong system memory infomation in sysfs. I think
>> it should be:
>> #define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS)
>>
>
> I guess the part below is not necessary for the changelog
>

Thanks for your suggestion, I will delete them in version 2.

>> linux-drf:/sys/devices/system/memory # ll
>> total 0
>> -r--r--r-- 1 root root 65536 Aug 20 02:35 block_size_bytes
>> drwxr-xr-x 3 root root 0 Aug 20 02:19 memory0
>> drwxr-xr-x 2 root root 0 Aug 20 02:35 power
>> -rw-r--r-- 1 root root 65536 Aug 20 02:35 uevent
>>
>> linux-drf:/sys/devices/system/memory # cat block_size_bytes
>> 0
>>
>> linux-drf:/sys/devices/system/memory/memory0 # cat *
>> 8000000000000000
>> cat: node0: Is a directory
>> cat: node1: Is a directory
>> cat: node2: Is a directory
>> cat: node3: Is a directory
>> 0
>> 8000000000000000
>> cat: power: Is a directory
>> 1
>> online
>> cat: subsystem: Is a directory
>>
>
> Up to here.
>
>> And "echo offline > memory0/state" will cause following call trace:
>>
>> kernel BUG at mm/memory_hotplug.c:885!
>> sh[6455]: bugcheck! 0 [1]
>>
>> Pid: 6455, CPU 0, comm: sh
>> psr : 0000101008526030 ifs : 8000000000000fa4 ip : [<a0000001008c40f0>] Not tainted (3.6.0-rc1)
>> ip is at offline_pages+0x210/0xee0
>> unat: 0000000000000000 pfs : 0000000000000fa4 rsc : 0000000000000003
>> rnat: a0000001008f2d50 bsps: 0000000000000000 pr : 65519a96659a9565
>> ldrs: 0000000000000000 ccv : 0000010b9263f310 fpsr: 0009804c0270033f
>> csd : 0000000000000000 ssd : 0000000000000000
>> b0 : a0000001008c40f0 b6 : a000000100473980 b7 : a0000001000106d0
>> f6 : 000000000000000000000 f7 : 1003e0000000085c9354c
>> f8 : 1003e0044b82fa09b5a53 f9 : 1003e000000d65cd62abf
>> f10 : 1003efd02efdec682803d f11 : 1003e0000000000000042
>> r1 : a00000010152c2e0 r2 : 0000000000006ada r3 : 000000000000fffe
>> r8 : 0000000000000026 r9 : a00000010121cc18 r10 : a0000001013309f0
>> r11 : 65519a96659a19e9 r12 : e00000070a91fdf0 r13 : e00000070a910000
>> r14 : 0000000000006ada r15 : 0000000000004000 r16 : 000000006ad8356c
>> r17 : a0000001019a525e r18 : 0000000000007fff r19 : 0000000000000000
>> r20 : 0000000000006ad6 r21 : 0000000000006ad6 r22 : a00000010133bec8
>> r23 : 0000000000006ad4 r24 : 0000000000000002 r25 : 8200000000260038
>> r26 : 00000000000004f9 r27 : 00000000000004f8 r28 : 000000000001cf98
>> r29 : 0000000000000038 r30 : a0000001019a5ae0 r31 : 000000000001cf60
>>
>> Call Trace:
>> [<a0000001000163e0>] show_stack+0x80/0xa0
>> sp=e00000070a91f9b0 bsp=e00000070a9115e0
>> [<a000000100016a40>] show_regs+0x640/0x920
>> sp=e00000070a91fb80 bsp=e00000070a911588
>> [<a000000100040590>] die+0x190/0x2c0
>> sp=e00000070a91fb90 bsp=e00000070a911548
>> [<a000000100040710>] die_if_kernel+0x50/0x80
>> sp=e00000070a91fb90 bsp=e00000070a911518
>> [<a0000001008f8030>] ia64_bad_break+0x3d0/0x6e0
>> sp=e00000070a91fb90 bsp=e00000070a9114f0
>> [<a00000010000c0c0>] ia64_native_leave_kernel+0x0/0x270
>> sp=e00000070a91fc20 bsp=e00000070a9114f0
>> [<a0000001008c40f0>] offline_pages+0x210/0xee0
>> sp=e00000070a91fdf0 bsp=e00000070a9113c8
>> [<a00000010022d580>] alloc_pages_current+0x180/0x2a0
>> sp=e00000070a91fe20 bsp=e00000070a9113a
>>
>> This patch is trying to fix the bug.
>
> not just trying ;)
>
>>
>> Signed-off-by: Jianguo Wu <[email protected]>
>
> Reviewed-by: Michal Hocko <[email protected]>
>
>> ---
>> include/linux/memory.h | 2 +-
>> 1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/include/linux/memory.h b/include/linux/memory.h
>> index 1ac7f6e..ff9a9f8 100644
>> --- a/include/linux/memory.h
>> +++ b/include/linux/memory.h
>> @@ -19,7 +19,7 @@
>> #include <linux/compiler.h>
>> #include <linux/mutex.h>
>>
>> -#define MIN_MEMORY_BLOCK_SIZE (1 << SECTION_SIZE_BITS)
>> +#define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS)
>>
>> struct memory_block {
>> unsigned long start_section_nr;
>