Remove two sources of outliers2013.12012.3

- Don't enforce sequentiality constraint on SEND_RESCHED samples.
- Refuse samples with negative time deltas (possible due to clock skew).

2 files changed, 14 insertions, 9 deletions

diff --git a/src/ft2csv.c b/src/ft2csv.c
index d8e8e95..6a0402d 100644
--- a/src/ft2csv.c
+++ b/src/ft2csv.c
@@ -289,7 +289,7 @@ static void find_event_by_eid(struct timestamp *first, struct timestamp* end)
         int interrupted = 0;
 
         second = find_second_ts(first, end, &interrupted);
-        if (second) {
+        if (second && second->timestamp > first->timestamp) {
                 exec_time = second->timestamp - first->timestamp;
                 if (first->task_type != TSK_RT &&
                          second->task_type != TSK_RT && !want_best_effort)
diff --git a/src/ftsort.c b/src/ftsort.c
index 42717fe..8ba0114 100644
--- a/src/ftsort.c
+++ b/src/ftsort.c
@@ -134,17 +134,21 @@ static void move_record(struct timestamp* target, struct timestamp* pos)
                 /* Refuse to violate task and CPU sequentiality: since CPUs and
                  * tasks execute sequentially, it makes no sense to move a
                  * timestamp before something recorded by the same task or
-                 * CPU. */
-                if (prev->cpu == pos->cpu ||
-                    prev->pid == pos->pid) {
+                 * CPU. Exception: TS_SEND_RESCHED_START is actually recorded
+                 * on a different CPU, so it is not subject to sequentiality
+                 * constraints.*/
+                if (prev->event != TS_SEND_RESCHED_START &&
+                    pos->event  != TS_SEND_RESCHED_START &&
+                    (prev->cpu == pos->cpu ||
+                     (prev->pid == pos->pid && pos->pid != 0))) {
                         /* Bail out before we cause more disturbance to the
                          * stream. */
                         aborted_moves++;
                         if (want_verbose)
-                                printf("Sequentiality constraint: "
-                                       "<ev:%s seq:%u pid:%u cpu:%u at %llu> "
-                                       "must come before "
-                                       "<ev:%s seq:%u pid:%u cpu:%u at %llu>\n",
+                                printf("Sequentiality constraint:\n"
+                                       "\t<ev:%s seq:%u pid:%u cpu:%u at %llu>\n"
+                                       "\tmust come before\n"
+                                       "\t<ev:%s seq:%u pid:%u cpu:%u at %llu>\n",
                                        event2str(prev->event),
                                        prev->seq_no, prev->pid, prev->cpu,
                                        (unsigned long long) prev->timestamp,
@@ -213,7 +217,8 @@ static void pre_check_cpu_monotonicity(struct timestamp *start,
                 prev[i] = pos[i] = NULL;
 
         for (next = start; next < end; next++) {
-                if (next->event >= SINGLE_RECORDS_RANGE)
+                if (next->event >= SINGLE_RECORDS_RANGE ||
+                    next->event == TS_SEND_RESCHED_START)
                         continue;
 
                 outlier = 0;