Messages in this thread | | | Date | Tue, 4 Aug 2009 13:53:15 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH 4/4] tracing, page-allocator: Add a postprocessing script for page-allocator-related ftrace events |
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On Tue, 4 Aug 2009 22:35:26 +0200 Ingo Molnar <mingo@elte.hu> wrote:
> Did you never want to see whether firefox is leaking [any sort of] > memory, and if yes, on what callsites? Try something like on an > already running firefox context: > > perf stat -e kmem:mm_page_alloc \ > -e kmem:mm_pagevec_free \ > -e kmem:mm_page_free_direct \ > -p $(pidof firefox-bin) sleep 10 > > ... and "perf record" for the specific callsites.
OK, that would be useful. What does the output look like?
In what way is it superior to existing ways of finding leaks?
> this perf stuff is immensely flexible and a very unixish > abstraction. The perf.data contains timestamped trace entries of > page allocations and freeing done. > > [...] > > It would be nice to at least partially remove the vmstat/meminfo > > infrastructure but I don't think we can do that? > > at least meminfo is an ABI for sure - vmstat too really. > > But we can stop adding new fields into obsolete, inflexible and > clearly deficient interfaces, and we can standardize new > instrumentation to use modern instrumentation facilities - i.e. > tracepoints and perfcounters.
That's bad. Is there really no way in which we can consolidate _any_ of that infrastructure? We just pile in new stuff alongside the old?
The worst part is needing two unrelated sets of userspace tools to access basically-identical things.
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