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.
Cc: Jiri Olsa <jo...@redhat.com>
Cc: Jean Pihet <jean.pi...@linaro.org>
Cc: Arun Sharma <asha...@fb.com>
Signed-off-by: Namhyung Kim <namhy...@kernel.org>
---
tools/perf/util/thread.c | 8 ++++++++
tools/perf/util/unwind-libunwind.c | 30 +++++++++++++++++++++++++-----
tools/perf/util/unwind.h | 17 +++++++++++++++++
3 files changed, 50 insertions(+), 5 deletions(-)
diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index a9df7f2c6dc9..c1fa4a3597ea 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -7,6 +7,7 @@
#include "util.h"
#include "debug.h"
#include "comm.h"
+#include "unwind.h"
int thread__init_map_groups(struct thread *thread, struct machine *machine)
{
@@ -48,6 +49,12 @@ struct thread *thread__new(pid_t pid, pid_t tid)
goto err_thread;
list_add(&comm->list, &thread->comm_list);
+
+ if (unwind__prepare_access(thread) < 0) {
+ list_del(&comm->list);
+ free(comm);
+ goto err_thread;
+ }
}
return thread;
@@ -69,6 +76,7 @@ void thread__delete(struct thread *thread)
list_del(&comm->list);
comm__free(comm);
}
+ unwind__finish_access(thread);
free(thread);
}
diff --git a/tools/perf/util/unwind-libunwind.c
b/tools/perf/util/unwind-libunwind.c
index 92b56db52471..76ec25663c95 100644
--- a/tools/perf/util/unwind-libunwind.c
+++ b/tools/perf/util/unwind-libunwind.c
@@ -525,12 +525,9 @@ static unw_accessors_t accessors = {
.get_proc_name = get_proc_name,
};
-static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb,
- void *arg, int max_stack)
+int unwind__prepare_access(struct thread *thread)
{
unw_addr_space_t addr_space;
- unw_cursor_t c;
- int ret;
addr_space = unw_create_addr_space(&accessors, 0);
if (!addr_space) {
@@ -538,6 +535,30 @@ static int get_entries(struct unwind_info *ui,
unwind_entry_cb_t cb,
return -ENOMEM;
}
+ thread__set_priv(thread, addr_space);
+
+ return 0;
+}
+
+void unwind__finish_access(struct thread *thread)
+{
+ unw_addr_space_t addr_space;
+
+ addr_space = thread__priv(thread);
+ unw_destroy_addr_space(addr_space);
+}
+
+static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb,
+ void *arg, int max_stack)
+{
+ unw_addr_space_t addr_space;
+ unw_cursor_t c;
+ int ret;
+
+ addr_space = thread__priv(ui->thread);
+ if (addr_space == NULL)
+ return -1;
+
ret = unw_init_remote(&c, addr_space, ui);
if (ret)
display_error(ret);
@@ -549,7 +570,6 @@ static int get_entries(struct unwind_info *ui,
unwind_entry_cb_t cb,
ret = ip ? entry(ip, ui->thread, ui->machine, cb, arg) : 0;
}
- unw_destroy_addr_space(addr_space);
return ret;
}
diff --git a/tools/perf/util/unwind.h b/tools/perf/util/unwind.h
index f03061260b4e..4b99c6280c2a 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 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
/* 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)
+{
+ return 0;
+}
+
+static inline void unwind__finish_access(struct thread *thread) {}
#endif
#else
static inline int
@@ -33,5 +43,12 @@ unwind__get_entries(unwind_entry_cb_t cb __maybe_unused,
{
return 0;
}
+
+static inline int unwind__prepare_access(struct thread *thread)
+{
+ return 0;
+}
+
+static inline void unwind__finish_access(struct thread *thread) {}
#endif /* HAVE_DWARF_UNWIND_SUPPORT */
#endif /* __UNWIND_H */
--
2.1.0
--
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