perf callchain: Create an address space per thread
The unw_addr_space_t in libunwind represents an address space to be used
for stack unwinding. It doesn't need to be create/destory everytime to
unwind callchain (as in get_entries) and can have a same lifetime as
thread (unless exec called).
So move the address space construction/destruction logic to the thread
lifetime handling functions. This is a preparation to enable caching in
the unwind library.
Note that it saves unw_addr_space_t object using thread__set_priv(). It
seems currently only used by perf trace and perf kvm stat commands which
don't use callchain.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jean Pihet <jean.pihet@linaro.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Arun Sharma <asharma@fb.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1412556363-26229-3-git-send-email-namhyung@kernel.org
[ Fixup unwind-libunwind.c missing CALLCHAIN_DWARF definition, added
missing __maybe_unused on unused parameters in stubs at util/unwind.h ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/unwind.h b/tools/perf/util/unwind.h
index f030612..c17c485 100644
--- a/tools/perf/util/unwind.h
+++ b/tools/perf/util/unwind.h
@@ -4,6 +4,7 @@
#include <linux/types.h>
#include "event.h"
#include "symbol.h"
+#include "thread.h"
struct unwind_entry {
struct map *map;
@@ -21,6 +22,15 @@
/* libunwind specific */
#ifdef HAVE_LIBUNWIND_SUPPORT
int libunwind__arch_reg_id(int regnum);
+int unwind__prepare_access(struct thread *thread);
+void unwind__finish_access(struct thread *thread);
+#else
+static inline int unwind__prepare_access(struct thread *thread __maybe_unused)
+{
+ return 0;
+}
+
+static inline void unwind__finish_access(struct thread *thread __maybe_unused) {}
#endif
#else
static inline int
@@ -33,5 +43,12 @@
{
return 0;
}
+
+static inline int unwind__prepare_access(struct thread *thread __maybe_unused)
+{
+ return 0;
+}
+
+static inline void unwind__finish_access(struct thread *thread __maybe_unused) {}
#endif /* HAVE_DWARF_UNWIND_SUPPORT */
#endif /* __UNWIND_H */