Messages in this thread | | | Date | Thu, 6 Aug 2009 16:54:51 +0100 | From | Mel Gorman <> | Subject | Re: [PATCH 4/4] tracing, page-allocator: Add a postprocessing script for page-allocator-related ftrace events |
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On Wed, Aug 05, 2009 at 10:53:50AM -0400, Larry Woodman wrote: > 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
I'd be surprised if you had, problems in page reclaim would be a lot more obvious for a start. The page allocator happened to be where I wanted tracepoints at the moment and I think the next patchset will act as a template for how to introduce tracepoints which can be repeated for the reclaim points.
> 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. >
Thanks.
-- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab
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