Make rocm_smi.py handle disappearing PIDs

rocm_smi.py had an issue where it gets process information
in 2 different places. If the process disappears in between
those 2 places, a crash would occur.

This fix gracefully returns in this scenario.
Reading the file information from /proc instead of using
the python subProcess() call was considered, but it has the
drawback of not being able to read the process names of
processes not owned by the caller.

Change-Id: If812c4641f00da37e99defb0740f670107c8a797

python_smi_tools/rocm_smi.py

@@ -250,7 +250,7 @@ def getMemInfo(device, memType):
     return (memUsed, memTotal)
 
 
-def getName(pid):
+def getProcessName(pid):
     """ Get the process name of a specific pid
 
     @param pid: Process ID of a program to be parsed
@@ -258,14 +258,21 @@ def getName(pid):
     if int(pid) < 1:
         logging.debug('PID must be greater than 0')
         return 'UNKNOWN'
-    pName = str(subprocess.check_output("ps -p %d -o comm=" % (int(pid)), shell=True))
+    try:
+        pName = str(subprocess.check_output("ps -p %d -o comm=" % (int(pid)), shell=True))
+    except subprocess.CalledProcessError as e:
+        print(e.output)
+        pName = 'UNKNOWN'
+
+    if pName == None:
+        pName = 'UNKNOWN'
+
     # Remove the substrings surrounding from process name (b' and \n')
     if str(pName).startswith('b\''):
         pName = pName[2:]
     if str(pName).endswith('\\n\''):
         pName = pName[:-3]
-    else:
-        pName = 'UNKNOWN'
+
     return pName
 
 
@@ -1664,7 +1671,7 @@ def showPids():
             cuOccupancy = proc.cu_occupancy
         else:
             logging.debug('Unable to fetch process info by PID')
-        dataArray.append([pid, getName(pid), str(gpuNumber), str(vramUsage), str(sdmaUsage), str(cuOccupancy)])
+        dataArray.append([pid, getProcessName(pid), str(gpuNumber), str(vramUsage), str(sdmaUsage), str(cuOccupancy)])
     printLog(None, 'KFD process information:', None)
     print2DArray(dataArray)
     printLogSpacer()