Commit-ID: ed6c166cc7dc329736cace3affd2df984fb22ec8
Gitweb: http://git.kernel.org/tip/ed6c166cc7dc329736cace3affd2df984fb22ec8
Author: Kan Liang <[email protected]>
AuthorDate: Tue, 13 Dec 2016 10:29:44 -0500
Committer: Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Tue, 20 Dec 2016 12:00:38 -0300
perf diff: Do not overwrite valid build id
Fixes a perf diff regression issue which was introduced by commit
5baecbcd9c9a ("perf symbols: we can now read separate debug-info files
based on a build ID")
The binary name could be same when perf diff different binaries. Build
id is used to distinguish between them.
However, the previous patch assumes the same binary name has same build
id. So it overwrites the build id according to the binary name,
regardless of whether the build id is set or not.
Check the has_build_id in dso__load. If the build id is already set, use
it.
Before the fix:
$ perf diff 1.perf.data 2.perf.data
# Event 'cycles'
#
# Baseline Delta Shared Object Symbol
# ........ ....... ................ .............................
#
99.83% -99.80% tchain_edit [.] f2
0.12% +99.81% tchain_edit [.] f3
0.02% -0.01% [ixgbe] [k] ixgbe_read_reg
After the fix:
$ perf diff 1.perf.data 2.perf.data
# Event 'cycles'
#
# Baseline Delta Shared Object Symbol
# ........ ....... ................ .............................
#
99.83% +0.10% tchain_edit [.] f3
0.12% -0.08% tchain_edit [.] f2
Signed-off-by: Kan Liang <[email protected]>
Cc: Andi Kleen <[email protected]>
CC: Dima Kogan <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Fixes: 5baecbcd9c9a ("perf symbols: we can now read separate debug-info files
based on a build ID")
Link:
http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/util/symbol.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index df2482b..dc93940 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1459,7 +1459,8 @@ int dso__load(struct dso *dso, struct map *map)
* Read the build id if possible. This is required for
* DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
*/
- if (is_regular_file(dso->long_name) &&
+ if (!dso->has_build_id &&
+ is_regular_file(dso->long_name) &&
filename__read_build_id(dso->long_name, build_id, BUILD_ID_SIZE) >
0)
dso__set_build_id(dso, build_id);
