perf buildid-cache: Add --update option

From: Namhyung Kim <[email protected]>

When adding vmlinux file to build-id cache, it'd be fail since kallsyms dso with a same build-id was already added by perf record. So one needs to remove the kallsyms first to add vmlinux into the cache. Add --update option for doing it at once.

---
 tools/perf/Documentation/perf-buildid-cache.txt |  4 ++
 tools/perf/builtin-buildid-cache.c              | 49 ++++++++++++++++++++++++-
 2 files changed, 52 insertions(+), 1 deletion(-)

index c1057701a7dc..3b0caf745964 100644
@@ -24,6 +24,10 @@ OPTIONS
 -r::
 --remove=::
         Remove specified file from the cache.
+-u::
+--update::
+	Update specified file of the cache. It can be used to update kallsyms
+	kernel dso to vmlinux in order to support annotation.
 -v::
 --verbose::
 	Be more verbose.

1.7.11.7

From: Namhyung Kim <[email protected]>

When perf report runs with perf.data which was recorded on a different kernel, it fails to run annotate browser with the kernel symbol and it recommends to run perf buildid-cache with proper vmlinux.

But running perf buildid-cache -av vmlinux as the message gives me a following error:

  $ perf buildid-cache -av /home/namhyung/build/kernel/vmlinux
  Couldn't add v: No such file or directory

Since the -a option receives a parameter, 'v' should not be after the option.

In addition -a option is not work for this case since the build-id cache already has a kallsyms with same build-id so it'll fail with EEXIST. Use recently added -u (--update) option for it.

---
 tools/perf/util/annotate.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 07aaeea60000..d33fe937e6f1 100644
@@ -809,7 +809,7 @@ fallback:
 		pr_err("Can't annotate %s:\n\n"
 		       "No vmlinux file%s\nwas found in the path.\n\n"
 		       "Please use:\n\n"
-		       "  perf buildid-cache -av vmlinux\n\n"
+		       "  perf buildid-cache -vu vmlinux\n\n"
 		       "or:\n\n"
 		       "  --vmlinux vmlinux\n",
 		       sym->name, build_id_msg ?: "");

1.7.11.7