Messages in this thread | | | Date | Wed, 7 Oct 2009 00:29:26 +0200 | From | Frederic Weisbecker <> | Subject | Re: [PATCH v2] perf tools: Start the perf.data mapping at data offset in perf trace |
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On Tue, Oct 06, 2009 at 09:21:26PM +0200, Frederic Weisbecker wrote: > Currently, we are mapping perf.data in the beginning of the file > and use the data offset as a buffer offset. This may exceed the > mapping area if the data offset is upper than page_size * mmap_window > and result in a page fault (thing that happen if we merge trace.info > in perf.data). > > Instead, let's start the mapping in the page that matches our data > offset. > > v2: Drop a junk from another patch (trace_report() removal) > > Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Arnaldo Carvalho de Melo <acme@redhat.com> > Cc: Mike Galbraith <efault@gmx.de> > Cc: Paul Mackerras <paulus@samba.org> > Cc: Tom Zanussi <tzanussi@gmail.com>
I just tested the trace.info drop with perf sched, and we have the same bug with mmap.
I guess we should rather have a common helper to use mmap on perf.data and rely on a callback to process the events. I'm putting this in my TODO list.
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