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

Christoph Lameter
2006-06-12T16:43:17Z

On Fri, 9 Jun 2006, Rohit Seth wrote:

> There is currently /proc/<pid>/smaps that prints the detailed
> information about the usage of physical pages but that is a very
> expensive operation as it traverses all the PTs (for some one who is
> just interested in getting that data for each vma).

Adding a new counter to a vma may cause a bouncing cacheline etc. I
would think that such a counter is far more expensive than occasional
scans through the page table because someone is curious about the
number of page in use. /proc/<pid>/numa_maps also uses these scans to
determine dirty pages etc.