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author | Jiri Olsa <jolsa@redhat.com> | 2012-09-10 18:50:19 +0200 |
---|---|---|
committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2012-09-11 17:08:30 +0200 |
commit | 7dbf4dcfe2987c35c2c4675cd7ae1b6006979176 (patch) | |
tree | ce04e8dd07222ed105d32a5ecb7b45f5469c68c4 /tools/perf/util/vdso.h | |
parent | perf symbols: Make dsos__find function globally available (diff) | |
download | linux-7dbf4dcfe2987c35c2c4675cd7ae1b6006979176.tar.xz linux-7dbf4dcfe2987c35c2c4675cd7ae1b6006979176.zip |
perf tools: Back [vdso] DSO with real data
Storing data for VDSO shared object, because we need it for the post
unwind processing.
The VDSO shared object is same for all process on a running system, so
it makes no difference when we store it inside the tracer - perf.
When [vdso] map memory is hit, we retrieve [vdso] DSO image and store it
into temporary file.
During the build-id processing phase, the [vdso] DSO image is stored in
build-id db, and build-id reference is made inside perf.data. The
build-id vdso file object is called '[vdso]'. We don't use temporary
file name which gets removed when record is finished.
During report phase the vdso build-id object is treated as any other
build-id DSO object.
Adding following API for vdso object:
bool is_vdso_map(const char *filename)
- returns true if the filename matches vdso map name
struct dso *vdso__dso_findnew(struct list_head *head)
- find/create proper vdso DSO object
vdso__exit(void)
- removes temporary VDSO image if there's any
This change makes backtrace dwarf post unwind possible from [vdso] maps.
Following output is current report of [vdso] sample dwarf backtrace:
# Overhead Command Shared Object Symbol
# ........ ....... ................. .............................
#
99.52% ex [vdso] [.] 0x00007fff3ace89af
|
--- 0x7fff3ace89af
Following output is new report of [vdso] sample dwarf backtrace:
# Overhead Command Shared Object Symbol
# ........ ....... ................. .............................
#
99.52% ex [vdso] [.] 0x00000000000009af
|
--- 0x7fff3ace89af
main
__libc_start_main
_start
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1347295819-23177-5-git-send-email-jolsa@redhat.com
[ committer note: s/ALIGN/PERF_ALIGN/g to cope with the android build changes ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/vdso.h')
-rw-r--r-- | tools/perf/util/vdso.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/tools/perf/util/vdso.h b/tools/perf/util/vdso.h new file mode 100644 index 000000000000..0f76e7caf6f8 --- /dev/null +++ b/tools/perf/util/vdso.h @@ -0,0 +1,18 @@ +#ifndef __PERF_VDSO__ +#define __PERF_VDSO__ + +#include <linux/types.h> +#include <string.h> +#include <stdbool.h> + +#define VDSO__MAP_NAME "[vdso]" + +static inline bool is_vdso_map(const char *filename) +{ + return !strcmp(filename, VDSO__MAP_NAME); +} + +struct dso *vdso__dso_findnew(struct list_head *head); +void vdso__exit(void); + +#endif /* __PERF_VDSO__ */ |