Re: [Lse-tech] Re: Performance of partial object-based rmap

[William Lee Irwin III]

On Fri, Feb 21, 2003 at 02:00:10AM -0800, William Lee Irwin III wrote:
> nr_page_table_pages                  689
> which amounts to 2756KB RAM used for PTE's, demonstrating large

Pagetables are also grossly fragmented. From the same sample:

nr_reverse_maps                   156027

To preempt the FAQ, this is the number of reverse mappings performed,
where one is done for every instantiated non-swap PTE.

$ echo $(( (689*1024)/156027.0 ))
4.5218840328917427

So the space flushed down the toilet there is also relatively large.
Approximately 4.5 PTE's per pagetable page, or a utilization of:

$ echo $(( (100*689)/156027.0 ))
0.44159023758708427

percent.

-- wli