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

Larry Woodman
2009-08-05T14:53:42Z

On Tue, 2009-08-04 at 21:48 +0100, Mel Gorman wrote:

> >
>
> Adding and deleting tracepoints, rebuilding and rebooting the kernel is
> obviously usable by developers but not a whole pile of use if
> recompiling the kernel is not an option or you're trying to debug a
> difficult-to-reproduce-but-is-happening-now type of problem.
>
> Of the CC list, I believe Larry Woodman has the most experience with
> these sort of problems in the field so I'm hoping he'll make some sort
> of comment.
>

I am all for adding tracepoints that eliminate the need to locate a
problem, add debug code, rebuild, reboot and retest until the real
problem is found.

Personally I have not seen as many problems in the page allocator as I
have in the page reclaim code thats why the majority of my tracepoints
were in vmscan.c However I do ACK this patch set because it provides
the opportunity to zoom into the page allocator dynamically without
needing to iterate through the cumbersome debug process.

Larry