Messages in this thread | | | Date | Thu, 31 Dec 2009 07:13:54 +0100 | From | Frederic Weisbecker <> | Subject | Re: [PATCH 1/2] perf: Pass appropriate frame pointer to dump_trace() |
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On Thu, Dec 31, 2009 at 05:53:02AM +0100, Frederic Weisbecker wrote: > Pass the frame pointer from the regs of the interrupted path > to dump_trace() while processing the stack trace. > > Currently, dump_trace() takes the current bp and starts the > callchain from dump_trace() itself. This is wasteful because > we need to walk through the entire NMI/DEBUG stack before > retrieving the interrupted point. > > We can fix that by just using the frame pointer from the captured > regs. It points exactly where we want to start.
BTW, another effect of this patch: we didn't have the nmi/debug stack frame filtering in x86-32. So the callchains were polluted by the perf_callchain path, do_debug and so on...
After this patch we don't need this filtering anymore as the nmi/debug frames are zapped. It becomes clean like in x86-64.
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