Re: [PATCH 4/4] tracing, page-allocator: Add a postprocessing script for page-allocator-related ftrace events

Andrew Morton
2009-08-04T18:23:51Z

On Tue, 4 Aug 2009 19:12:26 +0100 Mel Gorman <mel@csn.ul.ie> wrote:

> This patch adds a simple post-processing script for the page-allocator-related
> trace events. It can be used to give an indication of who the most
> allocator-intensive processes are and how often the zone lock was taken
> during the tracing period. Example output looks like
>
> find-2840
> o pages allocd = 1877
> o pages allocd under lock = 1817
> o pages freed directly = 9
> o pcpu refills = 1078
> o migrate fallbacks = 48
> - fragmentation causing = 48
> - severe = 46
> - moderate = 2
> - changed migratetype = 7

The usual way of accumulating and presenting such measurements is via
/proc/vmstat. How do we justify adding a completely new and different
way of doing something which we already do?