perf record: Add ability to sample call branches

This patch add a new branch type sampling filter to perf record.
It is named 'call' and maps to PERF_SAMPLE_BRANCH_CALL. It samples
direct call branches only, unlike 'any_call' which includes indirect
calls as well.

 $ perf record -j call -e cycles .....

The man page is updated accordingly.

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: khandual@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1444720151-10275-5-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

tools/perf/Documentation/perf-record.txt

@@ -236,6 +236,7 @@ following filters are defined:
         - any_call: any function call or system call
         - any_ret: any function return or system call return
         - ind_call: any indirect branch
+        - call: direct calls, including far (to/from kernel) calls
         - u:  only when the branch target is at the user level
         - k: only when the branch target is in the kernel
         - hv: only when the target is at the hypervisor level

tools/perf/util/parse-branch-options.c

@@ -27,6 +27,7 @@ static const struct branch_mode branch_modes[] = {
 	BRANCH_OPT("no_tx", PERF_SAMPLE_BRANCH_NO_TX),
 	BRANCH_OPT("cond", PERF_SAMPLE_BRANCH_COND),
 	BRANCH_OPT("ind_jmp", PERF_SAMPLE_BRANCH_IND_JUMP),
+	BRANCH_OPT("call", PERF_SAMPLE_BRANCH_CALL),
 	BRANCH_END
 };