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* [PATCH] mm/hugetlb: Use compound page head in migrate_huge_page
@ 2012-05-28 15:21 ` Aneesh Kumar K.V
  0 siblings, 0 replies; 8+ messages in thread
From: Aneesh Kumar K.V @ 2012-05-28 15:21 UTC (permalink / raw)
  To: linux-mm, kamezawa.hiroyu, mhocko, akpm, rientjes
  Cc: linux-kernel, Aneesh Kumar K.V

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

The change was introduced by "hugetlb: simplify migrate_huge_page() "

We should use compound page head instead of tail pages in
migrate_huge_page().

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 mm/memory-failure.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

This is an important bug fix. If we want we can fold it with the not
yet merged upstream patch mentioned above in linux-next. The stack
trace for the crash is

[   75.337421] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
[   75.338386] IP: [<ffffffff816b3f0f>] __mutex_lock_common+0xa1/0x350
[   75.338386] PGD 1d700067 PUD 1d7dd067 PMD 0
[   75.338386] Oops: 0002 [#1] SMP
[   75.338386] CPU 1
[   75.338386] Modules linked in:
...
...

[   75.338386] Call Trace:
[   75.338386]  [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c
[   75.338386]  [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c
[   75.338386]  [<ffffffff813b5f8b>] ? vsnprintf+0x83/0x421
[   75.338386]  [<ffffffff816b427d>] mutex_lock_nested+0x2a/0x31
[   75.338386]  [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55
[   75.338386]  [<ffffffff810ffc04>] try_to_unmap_file+0x38/0x51c
[   75.338386]  [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55
[   75.338386]  [<ffffffff810a06b9>] ? arch_local_irq_save+0x9/0xc
[   75.338386]  [<ffffffff816b5e3b>] ? _raw_spin_unlock+0x23/0x27
[   75.338386]  [<ffffffff81100839>] try_to_unmap+0x25/0x3c
[   75.338386]  [<ffffffff810641c2>] ? console_unlock+0x210/0x238
[   75.338386]  [<ffffffff811141e3>] migrate_huge_page+0x8d/0x178


diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 4a45098..53a1495 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1428,8 +1428,8 @@ static int soft_offline_huge_page(struct page *page, int flags)
 	}
 
 	/* Keep page count to indicate a given hugepage is isolated. */
-	ret = migrate_huge_page(page, new_page, MPOL_MF_MOVE_ALL, 0, true);
-	put_page(page);
+	ret = migrate_huge_page(hpage, new_page, MPOL_MF_MOVE_ALL, 0, true);
+	put_page(hpage);
 	if (ret) {
 		pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
 			pfn, ret, page->flags);
-- 
1.7.10


^ permalink raw reply related	[flat|nested] 8+ messages in thread
* [PATCH] mm/hugetlb: Use compound page head in migrate_huge_page
@ 2012-05-28 15:21 ` Aneesh Kumar K.V
  0 siblings, 0 replies; 8+ messages in thread
From: Aneesh Kumar K.V @ 2012-05-28 15:21 UTC (permalink / raw)
  To: linux-mm, kamezawa.hiroyu, mhocko, akpm, rientjes
  Cc: linux-kernel, Aneesh Kumar K.V

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

The change was introduced by "hugetlb: simplify migrate_huge_page() "

We should use compound page head instead of tail pages in
migrate_huge_page().

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 mm/memory-failure.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

This is an important bug fix. If we want we can fold it with the not
yet merged upstream patch mentioned above in linux-next. The stack
trace for the crash is

[   75.337421] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
[   75.338386] IP: [<ffffffff816b3f0f>] __mutex_lock_common+0xa1/0x350
[   75.338386] PGD 1d700067 PUD 1d7dd067 PMD 0
[   75.338386] Oops: 0002 [#1] SMP
[   75.338386] CPU 1
[   75.338386] Modules linked in:
...
...

[   75.338386] Call Trace:
[   75.338386]  [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c
[   75.338386]  [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c
[   75.338386]  [<ffffffff813b5f8b>] ? vsnprintf+0x83/0x421
[   75.338386]  [<ffffffff816b427d>] mutex_lock_nested+0x2a/0x31
[   75.338386]  [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55
[   75.338386]  [<ffffffff810ffc04>] try_to_unmap_file+0x38/0x51c
[   75.338386]  [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55
[   75.338386]  [<ffffffff810a06b9>] ? arch_local_irq_save+0x9/0xc
[   75.338386]  [<ffffffff816b5e3b>] ? _raw_spin_unlock+0x23/0x27
[   75.338386]  [<ffffffff81100839>] try_to_unmap+0x25/0x3c
[   75.338386]  [<ffffffff810641c2>] ? console_unlock+0x210/0x238
[   75.338386]  [<ffffffff811141e3>] migrate_huge_page+0x8d/0x178


diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 4a45098..53a1495 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1428,8 +1428,8 @@ static int soft_offline_huge_page(struct page *page, int flags)
 	}
 
 	/* Keep page count to indicate a given hugepage is isolated. */
-	ret = migrate_huge_page(page, new_page, MPOL_MF_MOVE_ALL, 0, true);
-	put_page(page);
+	ret = migrate_huge_page(hpage, new_page, MPOL_MF_MOVE_ALL, 0, true);
+	put_page(hpage);
 	if (ret) {
 		pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
 			pfn, ret, page->flags);
-- 
1.7.10

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply related	[flat|nested] 8+ messages in thread
* Re: [PATCH] mm/hugetlb: Use compound page head in migrate_huge_page
  2012-05-28 15:21 ` Aneesh Kumar K.V
@ 2012-05-28 19:13   ` Michal Hocko
  -1 siblings, 0 replies; 8+ messages in thread
From: Michal Hocko @ 2012-05-28 19:13 UTC (permalink / raw)
  To: Aneesh Kumar K.V; +Cc: linux-mm, kamezawa.hiroyu, akpm, rientjes, linux-kernel

On Mon 28-05-12 20:51:30, Aneesh Kumar K.V wrote:
> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
> 
> The change was introduced by "hugetlb: simplify migrate_huge_page() "
> 
> We should use compound page head instead of tail pages in
> migrate_huge_page().
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
>  mm/memory-failure.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> This is an important bug fix. If we want we can fold it with the not
> yet merged upstream patch mentioned above in linux-next. The stack
> trace for the crash is
> 
> [   75.337421] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
> [   75.338386] IP: [<ffffffff816b3f0f>] __mutex_lock_common+0xa1/0x350
> [   75.338386] PGD 1d700067 PUD 1d7dd067 PMD 0
> [   75.338386] Oops: 0002 [#1] SMP
> [   75.338386] CPU 1
> [   75.338386] Modules linked in:
> ...
> ...
> 
> [   75.338386] Call Trace:
> [   75.338386]  [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c
> [   75.338386]  [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c
> [   75.338386]  [<ffffffff813b5f8b>] ? vsnprintf+0x83/0x421
> [   75.338386]  [<ffffffff816b427d>] mutex_lock_nested+0x2a/0x31
> [   75.338386]  [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55
> [   75.338386]  [<ffffffff810ffc04>] try_to_unmap_file+0x38/0x51c
> [   75.338386]  [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55
> [   75.338386]  [<ffffffff810a06b9>] ? arch_local_irq_save+0x9/0xc
> [   75.338386]  [<ffffffff816b5e3b>] ? _raw_spin_unlock+0x23/0x27
> [   75.338386]  [<ffffffff81100839>] try_to_unmap+0x25/0x3c
> [   75.338386]  [<ffffffff810641c2>] ? console_unlock+0x210/0x238
> [   75.338386]  [<ffffffff811141e3>] migrate_huge_page+0x8d/0x178

This should be part of the changelog.

> 
> 
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 4a45098..53a1495 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -1428,8 +1428,8 @@ static int soft_offline_huge_page(struct page *page, int flags)
>  	}
>  
>  	/* Keep page count to indicate a given hugepage is isolated. */
> -	ret = migrate_huge_page(page, new_page, MPOL_MF_MOVE_ALL, 0, true);
> -	put_page(page);
> +	ret = migrate_huge_page(hpage, new_page, MPOL_MF_MOVE_ALL, 0, true);
> +	put_page(hpage);
>  	if (ret) {
>  		pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
>  			pfn, ret, page->flags);

I guess you want hpage->flags here.

-- 
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9    
Czech Republic

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: [PATCH] mm/hugetlb: Use compound page head in migrate_huge_page
@ 2012-05-28 19:13   ` Michal Hocko
  0 siblings, 0 replies; 8+ messages in thread
From: Michal Hocko @ 2012-05-28 19:13 UTC (permalink / raw)
  To: Aneesh Kumar K.V; +Cc: linux-mm, kamezawa.hiroyu, akpm, rientjes, linux-kernel

On Mon 28-05-12 20:51:30, Aneesh Kumar K.V wrote:
> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
> 
> The change was introduced by "hugetlb: simplify migrate_huge_page() "
> 
> We should use compound page head instead of tail pages in
> migrate_huge_page().
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
>  mm/memory-failure.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> This is an important bug fix. If we want we can fold it with the not
> yet merged upstream patch mentioned above in linux-next. The stack
> trace for the crash is
> 
> [   75.337421] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
> [   75.338386] IP: [<ffffffff816b3f0f>] __mutex_lock_common+0xa1/0x350
> [   75.338386] PGD 1d700067 PUD 1d7dd067 PMD 0
> [   75.338386] Oops: 0002 [#1] SMP
> [   75.338386] CPU 1
> [   75.338386] Modules linked in:
> ...
> ...
> 
> [   75.338386] Call Trace:
> [   75.338386]  [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c
> [   75.338386]  [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c
> [   75.338386]  [<ffffffff813b5f8b>] ? vsnprintf+0x83/0x421
> [   75.338386]  [<ffffffff816b427d>] mutex_lock_nested+0x2a/0x31
> [   75.338386]  [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55
> [   75.338386]  [<ffffffff810ffc04>] try_to_unmap_file+0x38/0x51c
> [   75.338386]  [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55
> [   75.338386]  [<ffffffff810a06b9>] ? arch_local_irq_save+0x9/0xc
> [   75.338386]  [<ffffffff816b5e3b>] ? _raw_spin_unlock+0x23/0x27
> [   75.338386]  [<ffffffff81100839>] try_to_unmap+0x25/0x3c
> [   75.338386]  [<ffffffff810641c2>] ? console_unlock+0x210/0x238
> [   75.338386]  [<ffffffff811141e3>] migrate_huge_page+0x8d/0x178

This should be part of the changelog.

> 
> 
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 4a45098..53a1495 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -1428,8 +1428,8 @@ static int soft_offline_huge_page(struct page *page, int flags)
>  	}
>  
>  	/* Keep page count to indicate a given hugepage is isolated. */
> -	ret = migrate_huge_page(page, new_page, MPOL_MF_MOVE_ALL, 0, true);
> -	put_page(page);
> +	ret = migrate_huge_page(hpage, new_page, MPOL_MF_MOVE_ALL, 0, true);
> +	put_page(hpage);
>  	if (ret) {
>  		pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
>  			pfn, ret, page->flags);

I guess you want hpage->flags here.

-- 
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9    
Czech Republic

--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: [PATCH] mm/hugetlb: Use compound page head in migrate_huge_page
  2012-05-28 19:13   ` Michal Hocko
@ 2012-05-29  3:18     ` Aneesh Kumar K.V
  -1 siblings, 0 replies; 8+ messages in thread
From: Aneesh Kumar K.V @ 2012-05-29  3:18 UTC (permalink / raw)
  To: Michal Hocko; +Cc: linux-mm, kamezawa.hiroyu, akpm, rientjes, linux-kernel

Michal Hocko <mhocko@suse.cz> writes:

> On Mon 28-05-12 20:51:30, Aneesh Kumar K.V wrote:
>> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>> 
>> The change was introduced by "hugetlb: simplify migrate_huge_page() "
>> 
>> We should use compound page head instead of tail pages in
>> migrate_huge_page().
>> 
>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>> ---
>>  mm/memory-failure.c |    4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>> 
>> This is an important bug fix. If we want we can fold it with the not
>> yet merged upstream patch mentioned above in linux-next. The stack
>> trace for the crash is
>> 
>> [   75.337421] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
>> [   75.338386] IP: [<ffffffff816b3f0f>] __mutex_lock_common+0xa1/0x350
>> [   75.338386] PGD 1d700067 PUD 1d7dd067 PMD 0
>> [   75.338386] Oops: 0002 [#1] SMP
>> [   75.338386] CPU 1
>> [   75.338386] Modules linked in:
>> ...
>> ...
>> 
>> [   75.338386] Call Trace:
>> [   75.338386]  [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c
>> [   75.338386]  [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c
>> [   75.338386]  [<ffffffff813b5f8b>] ? vsnprintf+0x83/0x421
>> [   75.338386]  [<ffffffff816b427d>] mutex_lock_nested+0x2a/0x31
>> [   75.338386]  [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55
>> [   75.338386]  [<ffffffff810ffc04>] try_to_unmap_file+0x38/0x51c
>> [   75.338386]  [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55
>> [   75.338386]  [<ffffffff810a06b9>] ? arch_local_irq_save+0x9/0xc
>> [   75.338386]  [<ffffffff816b5e3b>] ? _raw_spin_unlock+0x23/0x27
>> [   75.338386]  [<ffffffff81100839>] try_to_unmap+0x25/0x3c
>> [   75.338386]  [<ffffffff810641c2>] ? console_unlock+0x210/0x238
>> [   75.338386]  [<ffffffff811141e3>] migrate_huge_page+0x8d/0x178
>
> This should be part of the changelog.

I was expecting the patch to be folded back to the existing patch in
-mm. That is the reason I added stack trace in the notes section so that
if we decided to keep it as a separate patch we can pull the stack trace
and add it to commit message.


>
>> 
>> 
>> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
>> index 4a45098..53a1495 100644
>> --- a/mm/memory-failure.c
>> +++ b/mm/memory-failure.c
>> @@ -1428,8 +1428,8 @@ static int soft_offline_huge_page(struct page *page, int flags)
>>  	}
>>  
>>  	/* Keep page count to indicate a given hugepage is isolated. */
>> -	ret = migrate_huge_page(page, new_page, MPOL_MF_MOVE_ALL, 0, true);
>> -	put_page(page);
>> +	ret = migrate_huge_page(hpage, new_page, MPOL_MF_MOVE_ALL, 0, true);
>> +	put_page(hpage);
>>  	if (ret) {
>>  		pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
>>  			pfn, ret, page->flags);
>
> I guess you want hpage->flags here.

Existing code pass the flag details of the page passed as the
argument. I didn't want to change that.

-aneesh


^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: [PATCH] mm/hugetlb: Use compound page head in migrate_huge_page
@ 2012-05-29  3:18     ` Aneesh Kumar K.V
  0 siblings, 0 replies; 8+ messages in thread
From: Aneesh Kumar K.V @ 2012-05-29  3:18 UTC (permalink / raw)
  To: Michal Hocko; +Cc: linux-mm, kamezawa.hiroyu, akpm, rientjes, linux-kernel

Michal Hocko <mhocko@suse.cz> writes:

> On Mon 28-05-12 20:51:30, Aneesh Kumar K.V wrote:
>> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>> 
>> The change was introduced by "hugetlb: simplify migrate_huge_page() "
>> 
>> We should use compound page head instead of tail pages in
>> migrate_huge_page().
>> 
>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>> ---
>>  mm/memory-failure.c |    4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>> 
>> This is an important bug fix. If we want we can fold it with the not
>> yet merged upstream patch mentioned above in linux-next. The stack
>> trace for the crash is
>> 
>> [   75.337421] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
>> [   75.338386] IP: [<ffffffff816b3f0f>] __mutex_lock_common+0xa1/0x350
>> [   75.338386] PGD 1d700067 PUD 1d7dd067 PMD 0
>> [   75.338386] Oops: 0002 [#1] SMP
>> [   75.338386] CPU 1
>> [   75.338386] Modules linked in:
>> ...
>> ...
>> 
>> [   75.338386] Call Trace:
>> [   75.338386]  [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c
>> [   75.338386]  [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c
>> [   75.338386]  [<ffffffff813b5f8b>] ? vsnprintf+0x83/0x421
>> [   75.338386]  [<ffffffff816b427d>] mutex_lock_nested+0x2a/0x31
>> [   75.338386]  [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55
>> [   75.338386]  [<ffffffff810ffc04>] try_to_unmap_file+0x38/0x51c
>> [   75.338386]  [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55
>> [   75.338386]  [<ffffffff810a06b9>] ? arch_local_irq_save+0x9/0xc
>> [   75.338386]  [<ffffffff816b5e3b>] ? _raw_spin_unlock+0x23/0x27
>> [   75.338386]  [<ffffffff81100839>] try_to_unmap+0x25/0x3c
>> [   75.338386]  [<ffffffff810641c2>] ? console_unlock+0x210/0x238
>> [   75.338386]  [<ffffffff811141e3>] migrate_huge_page+0x8d/0x178
>
> This should be part of the changelog.

I was expecting the patch to be folded back to the existing patch in
-mm. That is the reason I added stack trace in the notes section so that
if we decided to keep it as a separate patch we can pull the stack trace
and add it to commit message.


>
>> 
>> 
>> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
>> index 4a45098..53a1495 100644
>> --- a/mm/memory-failure.c
>> +++ b/mm/memory-failure.c
>> @@ -1428,8 +1428,8 @@ static int soft_offline_huge_page(struct page *page, int flags)
>>  	}
>>  
>>  	/* Keep page count to indicate a given hugepage is isolated. */
>> -	ret = migrate_huge_page(page, new_page, MPOL_MF_MOVE_ALL, 0, true);
>> -	put_page(page);
>> +	ret = migrate_huge_page(hpage, new_page, MPOL_MF_MOVE_ALL, 0, true);
>> +	put_page(hpage);
>>  	if (ret) {
>>  		pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
>>  			pfn, ret, page->flags);
>
> I guess you want hpage->flags here.

Existing code pass the flag details of the page passed as the
argument. I didn't want to change that.

-aneesh

--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: [PATCH] mm/hugetlb: Use compound page head in migrate_huge_page
  2012-05-29  3:18     ` Aneesh Kumar K.V
@ 2012-05-29  9:58       ` Michal Hocko
  -1 siblings, 0 replies; 8+ messages in thread
From: Michal Hocko @ 2012-05-29  9:58 UTC (permalink / raw)
  To: Aneesh Kumar K.V; +Cc: linux-mm, kamezawa.hiroyu, akpm, rientjes, linux-kernel

On Tue 29-05-12 08:48:00, Aneesh Kumar K.V wrote:
> Michal Hocko <mhocko@suse.cz> writes:
> 
> > On Mon 28-05-12 20:51:30, Aneesh Kumar K.V wrote:
> >> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
> >> 
> >> The change was introduced by "hugetlb: simplify migrate_huge_page() "
> >> 
> >> We should use compound page head instead of tail pages in
> >> migrate_huge_page().
> >> 
> >> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> >> ---
> >>  mm/memory-failure.c |    4 ++--
> >>  1 file changed, 2 insertions(+), 2 deletions(-)
> >> 
> >> This is an important bug fix. If we want we can fold it with the not
> >> yet merged upstream patch mentioned above in linux-next. The stack
> >> trace for the crash is
> >> 
> >> [   75.337421] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
> >> [   75.338386] IP: [<ffffffff816b3f0f>] __mutex_lock_common+0xa1/0x350
> >> [   75.338386] PGD 1d700067 PUD 1d7dd067 PMD 0
> >> [   75.338386] Oops: 0002 [#1] SMP
> >> [   75.338386] CPU 1
> >> [   75.338386] Modules linked in:
> >> ...
> >> ...
> >> 
> >> [   75.338386] Call Trace:
> >> [   75.338386]  [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c
> >> [   75.338386]  [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c
> >> [   75.338386]  [<ffffffff813b5f8b>] ? vsnprintf+0x83/0x421
> >> [   75.338386]  [<ffffffff816b427d>] mutex_lock_nested+0x2a/0x31
> >> [   75.338386]  [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55
> >> [   75.338386]  [<ffffffff810ffc04>] try_to_unmap_file+0x38/0x51c
> >> [   75.338386]  [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55
> >> [   75.338386]  [<ffffffff810a06b9>] ? arch_local_irq_save+0x9/0xc
> >> [   75.338386]  [<ffffffff816b5e3b>] ? _raw_spin_unlock+0x23/0x27
> >> [   75.338386]  [<ffffffff81100839>] try_to_unmap+0x25/0x3c
> >> [   75.338386]  [<ffffffff810641c2>] ? console_unlock+0x210/0x238
> >> [   75.338386]  [<ffffffff811141e3>] migrate_huge_page+0x8d/0x178
> >
> > This should be part of the changelog.
> 
> I was expecting the patch to be folded back to the existing patch in
> -mm. That is the reason I added stack trace in the notes section so that
> if we decided to keep it as a separate patch we can pull the stack trace
> and add it to commit message.

OK.
-- 
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9    
Czech Republic

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: [PATCH] mm/hugetlb: Use compound page head in migrate_huge_page
@ 2012-05-29  9:58       ` Michal Hocko
  0 siblings, 0 replies; 8+ messages in thread
From: Michal Hocko @ 2012-05-29  9:58 UTC (permalink / raw)
  To: Aneesh Kumar K.V; +Cc: linux-mm, kamezawa.hiroyu, akpm, rientjes, linux-kernel

On Tue 29-05-12 08:48:00, Aneesh Kumar K.V wrote:
> Michal Hocko <mhocko@suse.cz> writes:
> 
> > On Mon 28-05-12 20:51:30, Aneesh Kumar K.V wrote:
> >> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
> >> 
> >> The change was introduced by "hugetlb: simplify migrate_huge_page() "
> >> 
> >> We should use compound page head instead of tail pages in
> >> migrate_huge_page().
> >> 
> >> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> >> ---
> >>  mm/memory-failure.c |    4 ++--
> >>  1 file changed, 2 insertions(+), 2 deletions(-)
> >> 
> >> This is an important bug fix. If we want we can fold it with the not
> >> yet merged upstream patch mentioned above in linux-next. The stack
> >> trace for the crash is
> >> 
> >> [   75.337421] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
> >> [   75.338386] IP: [<ffffffff816b3f0f>] __mutex_lock_common+0xa1/0x350
> >> [   75.338386] PGD 1d700067 PUD 1d7dd067 PMD 0
> >> [   75.338386] Oops: 0002 [#1] SMP
> >> [   75.338386] CPU 1
> >> [   75.338386] Modules linked in:
> >> ...
> >> ...
> >> 
> >> [   75.338386] Call Trace:
> >> [   75.338386]  [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c
> >> [   75.338386]  [<ffffffff810ffc04>] ? try_to_unmap_file+0x38/0x51c
> >> [   75.338386]  [<ffffffff813b5f8b>] ? vsnprintf+0x83/0x421
> >> [   75.338386]  [<ffffffff816b427d>] mutex_lock_nested+0x2a/0x31
> >> [   75.338386]  [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55
> >> [   75.338386]  [<ffffffff810ffc04>] try_to_unmap_file+0x38/0x51c
> >> [   75.338386]  [<ffffffff8110999b>] ? alloc_huge_page_node+0x1d/0x55
> >> [   75.338386]  [<ffffffff810a06b9>] ? arch_local_irq_save+0x9/0xc
> >> [   75.338386]  [<ffffffff816b5e3b>] ? _raw_spin_unlock+0x23/0x27
> >> [   75.338386]  [<ffffffff81100839>] try_to_unmap+0x25/0x3c
> >> [   75.338386]  [<ffffffff810641c2>] ? console_unlock+0x210/0x238
> >> [   75.338386]  [<ffffffff811141e3>] migrate_huge_page+0x8d/0x178
> >
> > This should be part of the changelog.
> 
> I was expecting the patch to be folded back to the existing patch in
> -mm. That is the reason I added stack trace in the notes section so that
> if we decided to keep it as a separate patch we can pull the stack trace
> and add it to commit message.

OK.
-- 
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9    
Czech Republic

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^ permalink raw reply	[flat|nested] 8+ messages in thread
end of thread, other threads:[~2012-05-29  9:58 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-05-28 15:21 [PATCH] mm/hugetlb: Use compound page head in migrate_huge_page Aneesh Kumar K.V
2012-05-28 15:21 ` Aneesh Kumar K.V
2012-05-28 19:13 ` Michal Hocko
2012-05-28 19:13   ` Michal Hocko
2012-05-29  3:18   ` Aneesh Kumar K.V
2012-05-29  3:18     ` Aneesh Kumar K.V
2012-05-29  9:58     ` Michal Hocko
2012-05-29  9:58       ` Michal Hocko

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