Commit 66f066d8 authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo

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: default avatarNamhyung Kim <namhyung@kernel.org>
Acked-by: default avatarJean Pihet <jean.pihet@linaro.org>
Acked-by: default avatarJiri 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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 0cdccac6
......@@ -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)
{
......@@ -37,6 +38,9 @@ struct thread *thread__new(pid_t pid, pid_t tid)
thread->cpu = -1;
INIT_LIST_HEAD(&thread->comm_list);
if (unwind__prepare_access(thread) < 0)
goto err_thread;
comm_str = malloc(32);
if (!comm_str)
goto err_thread;
......@@ -48,6 +52,7 @@ struct thread *thread__new(pid_t pid, pid_t tid)
goto err_thread;
list_add(&comm->list, &thread->comm_list);
}
return thread;
......@@ -69,6 +74,7 @@ void thread__delete(struct thread *thread)
list_del(&comm->list);
comm__free(comm);
}
unwind__finish_access(thread);
free(thread);
}
......
......@@ -24,6 +24,7 @@
#include <linux/list.h>
#include <libunwind.h>
#include <libunwind-ptrace.h>
#include "callchain.h"
#include "thread.h"
#include "session.h"
#include "perf_regs.h"
......@@ -525,12 +526,12 @@ 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;
if (callchain_param.record_mode != CALLCHAIN_DWARF)
return 0;
addr_space = unw_create_addr_space(&accessors, 0);
if (!addr_space) {
......@@ -538,6 +539,33 @@ 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;
if (callchain_param.record_mode != CALLCHAIN_DWARF)
return;
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 +577,6 @@ 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;
}
......
......@@ -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 __maybe_unused)
{
return 0;
}
static inline void unwind__finish_access(struct thread *thread __maybe_unused) {}
#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 __maybe_unused)
{
return 0;
}
static inline void unwind__finish_access(struct thread *thread __maybe_unused) {}
#endif /* HAVE_DWARF_UNWIND_SUPPORT */
#endif /* __UNWIND_H */
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