[PATCH] docs: mm: fix the incorrect 'FileHugeMapped' field

[PATCH] docs: mm: fix the incorrect 'FileHugeMapped' field

[Baolin Wang]

The '/proc/PID/smaps' does not have the 'FileHugeMapped' field to count the
file transparent huge pages, instead, the 'FilePmdMapped' field should be
used. Fix it.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
---
 Documentation/admin-guide/mm/transhuge.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
index 156a03af0a88..dff8d5985f0f 100644
--- a/Documentation/admin-guide/mm/transhuge.rst
+++ b/Documentation/admin-guide/mm/transhuge.rst
@@ -466,7 +466,7 @@ AnonHugePmdMapped).
 The number of file transparent huge pages mapped to userspace is available
 by reading ShmemPmdMapped and ShmemHugePages fields in ``/proc/meminfo``.
 To identify what applications are mapping file transparent huge pages, it
-is necessary to read ``/proc/PID/smaps`` and count the FileHugeMapped fields
+is necessary to read ``/proc/PID/smaps`` and count the FilePmdMapped fields
 for each mapping.
 
 Note that reading the smaps file is expensive and reading it
-- 
2.39.3

Re: [PATCH] docs: mm: fix the incorrect 'FileHugeMapped' field

[David Hildenbrand]

On 17.12.24 09:55, Baolin Wang wrote:
> The '/proc/PID/smaps' does not have the 'FileHugeMapped' field to count the
> file transparent huge pages, instead, the 'FilePmdMapped' field should be
> used. Fix it.
> 
> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> ---
>   Documentation/admin-guide/mm/transhuge.rst | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
> index 156a03af0a88..dff8d5985f0f 100644
> --- a/Documentation/admin-guide/mm/transhuge.rst
> +++ b/Documentation/admin-guide/mm/transhuge.rst
> @@ -466,7 +466,7 @@ AnonHugePmdMapped).
>   The number of file transparent huge pages mapped to userspace is available
>   by reading ShmemPmdMapped and ShmemHugePages fields in ``/proc/meminfo``.
>   To identify what applications are mapping file transparent huge pages, it
> -is necessary to read ``/proc/PID/smaps`` and count the FileHugeMapped fields
> +is necessary to read ``/proc/PID/smaps`` and count the FilePmdMapped fields
>   for each mapping.

We should probably change the above to clarify that this is all about 
PMD sized things.

Acked-by: David Hildenbrand <david@redhat.com>

-- 
Cheers,

David / dhildenb

Re: [PATCH] docs: mm: fix the incorrect 'FileHugeMapped' field

[Baolin Wang]

On 2024/12/17 19:59, David Hildenbrand wrote:
> On 17.12.24 09:55, Baolin Wang wrote:
>> The '/proc/PID/smaps' does not have the 'FileHugeMapped' field to 
>> count the
>> file transparent huge pages, instead, the 'FilePmdMapped' field should be
>> used. Fix it.
>>
>> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
>> ---
>>   Documentation/admin-guide/mm/transhuge.rst | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/Documentation/admin-guide/mm/transhuge.rst 
>> b/Documentation/admin-guide/mm/transhuge.rst
>> index 156a03af0a88..dff8d5985f0f 100644
>> --- a/Documentation/admin-guide/mm/transhuge.rst
>> +++ b/Documentation/admin-guide/mm/transhuge.rst
>> @@ -466,7 +466,7 @@ AnonHugePmdMapped).
>>   The number of file transparent huge pages mapped to userspace is 
>> available
>>   by reading ShmemPmdMapped and ShmemHugePages fields in 
>> ``/proc/meminfo``.
>>   To identify what applications are mapping file transparent huge 
>> pages, it
>> -is necessary to read ``/proc/PID/smaps`` and count the FileHugeMapped 
>> fields
>> +is necessary to read ``/proc/PID/smaps`` and count the FilePmdMapped 
>> fields
>>   for each mapping.
> 
> We should probably change the above to clarify that this is all about 
> PMD sized things.

Yes, I will create a separate patch to update the document where it 
needs to specify that it is for PMD-sized huge page.

> Acked-by: David Hildenbrand <david@redhat.com>

Thanks.