perf tool: Fix gcc 4.6.0 issues

GCC 4.6.0 in Fedora rawhide turned up some compile errors in tools/perf
due to the -Werror=unused-but-set-variable flag.

I've gone through and annotated some of the assignments that had side
effects (ie: return value from a function) with the __used annotation,
and in some cases, just removed unused code.

In a few cases, we were assigning something useful, but not using it in
later parts of the function.

kyle@dreadnought:~/src% gcc --version
gcc (GCC) 4.6.0 20110122 (Red Hat 4.6.0-0.3)

Cc: Ingo Molnar <mingo@redhat.com>
LKML-Reference: <20110124161304.GK27353@bombadil.infradead.org>
Signed-off-by: Kyle McMartin <kyle@redhat.com>
[ committer note: Fixed up the annotation fixes, as that code moved recently ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 3 insertions, 9 deletions

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index ae2621182927..a32f411faeac 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -369,11 +369,6 @@ static void
 process_sched_event(struct task_desc *this_task __used, struct sched_atom *atom)
 {
         int ret = 0;
-        u64 now;
-        long long delta;
-
-        now = get_nsecs();
-        delta = start_time + atom->timestamp - now;
 
         switch (atom->type) {
                 case SCHED_EVENT_RUN:
@@ -562,7 +557,7 @@ static void wait_for_tasks(void)
 
 static void run_one_test(void)
 {
-        u64 T0, T1, delta, avg_delta, fluct, std_dev;
+        u64 T0, T1, delta, avg_delta, fluct;
 
         T0 = get_nsecs();
         wait_for_tasks();
@@ -578,7 +573,6 @@ static void run_one_test(void)
         else
                 fluct = delta - avg_delta;
         sum_fluct += fluct;
-        std_dev = sum_fluct / nr_runs / sqrt(nr_runs);
         if (!run_avg)
                 run_avg = delta;
         run_avg = (run_avg*9 + delta)/10;
@@ -799,7 +793,7 @@ replay_switch_event(struct trace_switch_event *switch_event,
                     u64 timestamp,
                     struct thread *thread __used)
 {
-        struct task_desc *prev, *next;
+        struct task_desc *prev, __used *next;
         u64 timestamp0;
         s64 delta;
 
@@ -1404,7 +1398,7 @@ map_switch_event(struct trace_switch_event *switch_event,
                  u64 timestamp,
                  struct thread *thread __used)
 {
-        struct thread *sched_out, *sched_in;
+        struct thread *sched_out __used, *sched_in;
         int new_shortname;
         u64 timestamp0;
         s64 delta;