Re: [PATCH]: Adding a counter in vma to indicate the number of physical pages backing it

Nick Piggin
2006-06-13T04:27:20Z

Andi Kleen wrote:

>On Monday 12 June 2006 21:42, Rohit Seth wrote:
>
>>I think having this
>>information in each vma keeps the impact (of adding new counter) to very
>>low.
>>
>>Second question is to advertize this value to user space. Please let me
>>know what suites the most among /proc, /sys or system call (or if there
>>is any other mechanism then let me know) for a per process per segment
>>related information.
>>
>
>I think we first need to identify the basic need.
>Don't see why we even need per VMA information so far.
>

Exactly. There is no question that walking page tables will be slower
than having a counter like your patch does; the question is why we
need it.

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