pcp-system-tools: restore backward compatibility with older pmapi versions

src/pcp/iostat/pcp-iostat.py

@@ -56,9 +56,18 @@ class IostatReport(pmcc.MetricGroupPrinter):
     Hcount = 0
     def timeStampDelta(self, group):
         s = group.timestamp.tv_sec - group.prevTimestamp.tv_sec
-        n = group.timestamp.tv_nsec - group.prevTimestamp.tv_nsec
-        # n may be negative here, calculation is still correct.
-        return s + n / 1000000000.0
+        # pmapi timestamps may provide sub-second resolution via tv_nsec (nanoseconds)
+        # or tv_usec (microseconds) depending on the collector. Prefer nanoseconds
+        # when available, but gracefully fall back to microseconds to avoid
+        if hasattr(group.timestamp, 'tv_nsec') and hasattr(group.prevTimestamp, 'tv_nsec'):
+            n = group.timestamp.tv_nsec - group.prevTimestamp.tv_nsec
+            # n may be negative here, calculation is still correct.
+            return s + n / 1_000_000_000.0
+        elif hasattr(group.timestamp, 'tv_usec') and hasattr(group.prevTimestamp, 'tv_usec'):
+            u = group.timestamp.tv_usec - group.prevTimestamp.tv_usec
+            return s + u / 1_000_000.0
+        # it should not reach here
+        return s
 
     def instlist(self, group, name):
         return dict(map(lambda x: (x[1], x[2]), group[name].netValues)).keys()

src/pcp/mpstat/pcp-mpstat.py

@@ -499,8 +499,17 @@ def __init__(self, cpu_util_reporter, total_interrupt_usage_reporter, soft_inter
 
     def timeStampDelta(self, group):
         s = group.timestamp.tv_sec - group.prevTimestamp.tv_sec
-        n = group.timestamp.tv_nsec - group.prevTimestamp.tv_nsec
-        return s + n / 1000000000.0
+        # pmapi timestamps may provide sub-second resolution via tv_nsec (nanoseconds)
+        # or tv_usec (microseconds) depending on the collector. Prefer nanoseconds
+        # when available, but gracefully fall back to microseconds to avoid
+        if hasattr(group.timestamp, 'tv_nsec') and hasattr(group.prevTimestamp, 'tv_nsec'):
+            n = group.timestamp.tv_nsec - group.prevTimestamp.tv_nsec
+            return s + n / 1_000_000_000.0
+        elif hasattr(group.timestamp, 'tv_usec') and hasattr(group.prevTimestamp, 'tv_usec'):
+            u = group.timestamp.tv_usec - group.prevTimestamp.tv_usec
+            return s + u / 1_000_000.0
+        # it should not reach here
+        return s
 
     def print_machine_info(self,group, context):
         self.get_summary_metrics(group)

src/pcp/pidstat/pcp-pidstat.py

@@ -925,8 +925,17 @@ class PidstatReport(pmcc.MetricGroupPrinter):
 
     def timeStampDelta(self, group):
         s = group.timestamp.tv_sec - group.prevTimestamp.tv_sec
-        n = group.timestamp.tv_nsec - group.prevTimestamp.tv_nsec
-        return s + n / 1000000000.0
+        # pmapi timestamps may provide sub-second resolution via tv_nsec (nanoseconds)
+        # or tv_usec (microseconds) depending on the collector. Prefer nanoseconds
+        # when available, but gracefully fall back to microseconds to avoid
+        if hasattr(group.timestamp, 'tv_nsec') and hasattr(group.prevTimestamp, 'tv_nsec'):
+            n = group.timestamp.tv_nsec - group.prevTimestamp.tv_nsec
+            return s + n / 1_000_000_000.0
+        elif hasattr(group.timestamp, 'tv_usec') and hasattr(group.prevTimestamp, 'tv_usec'):
+            u = group.timestamp.tv_usec - group.prevTimestamp.tv_usec
+            return s + u / 1_000_000.0
+        # it should not reach here
+        return s
 
     def print_machine_info(self,group, context):
         timestamp = context.pmLocaltime(group.timestamp.tv_sec)

src/pcp/ps/pcp-ps.py

@@ -585,8 +585,17 @@ def __init__(self, group=None, options = None):
 
     def timeStampDelta(self):
         s = self.group.timestamp.tv_sec - self.group.prevTimestamp.tv_sec
-        n = self.group.timestamp.tv_nsec - self.group.prevTimestamp.tv_nsec
-        return s + n / 1000000000.0
+        # pmapi timestamps may provide sub-second resolution via tv_nsec (nanoseconds)
+        # or tv_usec (microseconds) depending on the collector. Prefer nanoseconds
+        # when available, but gracefully fall back to microseconds to avoid
+        if hasattr(self.group.timestamp, 'tv_nsec') and hasattr(self.group.prevTimestamp, 'tv_nsec'):
+            n = self.group.timestamp.tv_nsec - self.group.prevTimestamp.tv_nsec
+            return s + n / 1_000_000_000.0
+        elif hasattr(self.group.timestamp, 'tv_usec') and hasattr(self.group.prevTimestamp, 'tv_usec'):
+            u = self.group.timestamp.tv_usec - self.group.prevTimestamp.tv_usec
+            return s + u / 1_000_000.0
+        # it should not reach here
+        return s
 
     def print_machine_info(self,context):
         timestamp = context.pmLocaltime(self.group.timestamp.tv_sec)

src/pcp/tapestat/pcp-tapestat.py

@@ -68,9 +68,18 @@ class TapestatReport(pmcc.MetricGroupPrinter):
     Hcount = 0
     def timeStampDelta(self, group):
         s = group.timestamp.tv_sec - group.prevTimestamp.tv_sec
-        n = group.timestamp.tv_nsec - group.prevTimestamp.tv_nsec
-        # n may be negative here, calculation is still correct.
-        return s + n / 1000000000.0
+        # pmapi timestamps may provide sub-second resolution via tv_nsec (nanoseconds)
+        # or tv_usec (microseconds) depending on the collector. Prefer nanoseconds
+        # when available, but gracefully fall back to microseconds to avoid
+        if hasattr(group.timestamp, 'tv_nsec') and hasattr(group.prevTimestamp, 'tv_nsec'):
+            n = group.timestamp.tv_nsec - group.prevTimestamp.tv_nsec
+            # n may be negative here, calculation is still correct.
+            return s + n / 1_000_000_000.0
+        elif hasattr(group.timestamp, 'tv_usec') and hasattr(group.prevTimestamp, 'tv_usec'):
+            u = group.timestamp.tv_usec - group.prevTimestamp.tv_usec
+            return s + u / 1_000_000.0
+        # it should not reach here
+        return s
     def instlist(self, group, name):
         return dict(map(lambda x: (x[1], x[2]), group[name].netValues)).keys()