[PATCH 27/38] perf callchain: Maintain libunwind's address space in map_groups

From: Namhyung Kim
Date: Mon Mar 02 2015 - 22:15:44 EST


Currently the address_space was kept in thread struct but it's more
appropriate to keep it in map_groups as it's maintained with time.
Also we don't need to flush after exec since it still can be accessed
when used with an indexed data file.

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/tests/dwarf-unwind.c | 4 ++--
tools/perf/util/map.c | 5 +++++
tools/perf/util/map.h | 1 +
tools/perf/util/thread.c | 8 --------
tools/perf/util/unwind-libunwind.c | 28 +++++++++++++---------------
tools/perf/util/unwind.h | 15 ++++++---------
6 files changed, 27 insertions(+), 34 deletions(-)

diff --git a/tools/perf/tests/dwarf-unwind.c b/tools/perf/tests/dwarf-unwind.c
index 241270374e93..0fa26e77e28a 100644
--- a/tools/perf/tests/dwarf-unwind.c
+++ b/tools/perf/tests/dwarf-unwind.c
@@ -143,6 +143,8 @@ int test__dwarf_unwind(void)
struct thread *thread;
int err = -1;

+ callchain_param.record_mode = CALLCHAIN_DWARF;
+
machines__init(&machines);

machine = machines__find(&machines, HOST_KERNEL_ID);
@@ -151,8 +153,6 @@ int test__dwarf_unwind(void)
return -1;
}

- callchain_param.record_mode = CALLCHAIN_DWARF;
-
if (init_live_machine(machine)) {
pr_err("Could not init machine\n");
goto out;
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 85fbb1b3e69f..c7eeabafa6c9 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -14,6 +14,7 @@
#include "util.h"
#include "debug.h"
#include "machine.h"
+#include "unwind.h"
#include <linux/string.h>

const char *map_type__name[MAP__NR_TYPES] = {
@@ -424,6 +425,8 @@ void map_groups__init(struct map_groups *mg, struct machine *machine)
mg->refcnt = 1;
mg->timestamp = 0;
INIT_LIST_HEAD(&mg->list);
+
+ unwind__prepare_access(mg);
}

static void maps__delete(struct rb_root *maps)
@@ -457,6 +460,8 @@ void map_groups__exit(struct map_groups *mg)
maps__delete(&mg->maps[i]);
maps__delete_removed(&mg->removed_maps[i]);
}
+
+ unwind__finish_access(mg);
}

bool map_groups__empty(struct map_groups *mg)
diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
index f33d49029ac0..f7db4a010dc8 100644
--- a/tools/perf/util/map.h
+++ b/tools/perf/util/map.h
@@ -64,6 +64,7 @@ struct map_groups {
u64 timestamp;
int refcnt;
struct list_head list;
+ void *priv;
};

struct map_groups *map_groups__new(struct machine *machine);
diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 9ae1ce8606af..552e1a56af6a 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -8,7 +8,6 @@
#include "util.h"
#include "debug.h"
#include "comm.h"
-#include "unwind.h"

struct map_groups *thread__get_map_groups(struct thread *thread, u64 timestamp)
{
@@ -104,9 +103,6 @@ struct thread *thread__new(pid_t pid, pid_t tid)
INIT_LIST_HEAD(&thread->tid_node);
INIT_LIST_HEAD(&thread->mg_list);

- if (unwind__prepare_access(thread) < 0)
- goto err_thread;
-
comm_str = malloc(32);
if (!comm_str)
goto err_thread;
@@ -147,7 +143,6 @@ void thread__delete(struct thread *thread)
list_del(&comm->list);
comm__free(comm);
}
- unwind__finish_access(thread);

free(thread);
}
@@ -216,9 +211,6 @@ int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
break;
}
list_add_tail(&new->list, &curr->list);
-
- if (exec)
- unwind__flush_access(thread);
}

if (exec) {
diff --git a/tools/perf/util/unwind-libunwind.c b/tools/perf/util/unwind-libunwind.c
index 9ee63179383e..9d7ecb26fde9 100644
--- a/tools/perf/util/unwind-libunwind.c
+++ b/tools/perf/util/unwind-libunwind.c
@@ -32,6 +32,7 @@
#include "symbol.h"
#include "util.h"
#include "debug.h"
+#include "map.h"

extern int
UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as,
@@ -560,7 +561,7 @@ static unw_accessors_t accessors = {
.get_proc_name = get_proc_name,
};

-int unwind__prepare_access(struct thread *thread)
+int unwind__prepare_access(struct map_groups *mg)
{
unw_addr_space_t addr_space;

@@ -574,41 +575,38 @@ int unwind__prepare_access(struct thread *thread)
}

unw_set_caching_policy(addr_space, UNW_CACHE_GLOBAL);
- thread__set_priv(thread, addr_space);
+ mg->priv = addr_space;

return 0;
}

-void unwind__flush_access(struct thread *thread)
+void unwind__finish_access(struct map_groups *mg)
{
- unw_addr_space_t addr_space;
+ unw_addr_space_t addr_space = mg->priv;

if (callchain_param.record_mode != CALLCHAIN_DWARF)
return;

- addr_space = thread__priv(thread);
- unw_flush_cache(addr_space, 0, 0);
-}
-
-void unwind__finish_access(struct thread *thread)
-{
- unw_addr_space_t addr_space;
-
- if (callchain_param.record_mode != CALLCHAIN_DWARF)
+ if (addr_space == NULL)
return;

- addr_space = thread__priv(thread);
unw_destroy_addr_space(addr_space);
+ mg->priv = NULL;
}

static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb,
void *arg, int max_stack)
{
+ struct map_groups *mg;
unw_addr_space_t addr_space;
unw_cursor_t c;
int ret;

- addr_space = thread__priv(ui->thread);
+ mg = thread__get_map_groups(ui->thread, ui->sample->time);
+ if (mg == NULL)
+ return -1;
+
+ addr_space = mg->priv;
if (addr_space == NULL)
return -1;

diff --git a/tools/perf/util/unwind.h b/tools/perf/util/unwind.h
index c619890e60ad..b3833eaf4c3b 100644
--- a/tools/perf/util/unwind.h
+++ b/tools/perf/util/unwind.h
@@ -21,17 +21,15 @@ 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__flush_access(struct thread *thread);
-void unwind__finish_access(struct thread *thread);
+int unwind__prepare_access(struct map_groups *mg);
+void unwind__finish_access(struct map_groups *mg);
#else
-static inline int unwind__prepare_access(struct thread *thread __maybe_unused)
+static inline int unwind__prepare_access(struct map_groups *mg __maybe_unused)
{
return 0;
}

-static inline void unwind__flush_access(struct thread *thread __maybe_unused) {}
-static inline void unwind__finish_access(struct thread *thread __maybe_unused) {}
+static inline void unwind__finish_access(struct map_groups *mg __maybe_unused) {}
#endif
#else
static inline int
@@ -45,12 +43,11 @@ unwind__get_entries(unwind_entry_cb_t cb __maybe_unused,
return 0;
}

-static inline int unwind__prepare_access(struct thread *thread __maybe_unused)
+static inline int unwind__prepare_access(struct map_groups *mg __maybe_unused)
{
return 0;
}

-static inline void unwind__flush_access(struct thread *thread __maybe_unused) {}
-static inline void unwind__finish_access(struct thread *thread __maybe_unused) {}
+static inline void unwind__finish_access(struct map_groups *mg __maybe_unused) {}
#endif /* HAVE_DWARF_UNWIND_SUPPORT */
#endif /* __UNWIND_H */
--
2.2.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/