perf: Pass appropriate frame pointer to dump_trace()

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.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1262235183-5320-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Frederic Weisbecker 2009-12-31 05:53:02 +01:00 committed by Ingo Molnar
parent 4efb5290ae
commit 48b5ba9cc9

View File

@ -2347,7 +2347,7 @@ perf_callchain_kernel(struct pt_regs *regs, struct perf_callchain_entry *entry)
callchain_store(entry, PERF_CONTEXT_KERNEL);
callchain_store(entry, regs->ip);
dump_trace(NULL, regs, NULL, 0, &backtrace_ops, entry);
dump_trace(NULL, regs, NULL, regs->bp, &backtrace_ops, entry);
}
/*