From a4fdd27814ed7b4f2f6f609a72364b581ec19bc0 Mon Sep 17 00:00:00 2001
From: Arnaldo Carvalho de Melo <acme@felicio.ghostprotocols.net>
Date: Tue, 9 Jun 2015 16:15:42 -0300
Subject: [PATCH 12/15] tuna: Fix race in is_hardirq_handler

It is better to try accessing the fields catching exceptions, as just
checking if we have that key is not enough for, right after, that thread
having gone away and the populating of that dict entry not finding the
file on /proc/PID/.

Signed-off-by: Arnaldo Carvalho de Melo <acme@felicio.ghostprotocols.net>
Signed-off-by: John Kacur <jkacur@redhat.com>
---
 tuna/tuna.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/tuna/tuna.py b/tuna/tuna.py
index 6cd6bddd2137..3c30f03ea134 100755
--- a/tuna/tuna.py
+++ b/tuna/tuna.py
@@ -166,10 +166,11 @@ def list_to_cpustring(l):
 # FIXME: move to python-linux-procfs
 def is_hardirq_handler(self, pid):
 		PF_HARDIRQ = 0x08000000
-		if not self.processes.has_key(pid):
+		try:
+			return int(self.processes[pid]["stat"]["flags"]) & \
+				PF_HARDIRQ and True or False
+		except:
 			return False
-                return int(self.processes[pid]["stat"]["flags"]) & \
-                       PF_HARDIRQ and True or False
 
 # FIXME: move to python-linux-procfs
 def cannot_set_affinity(self, pid):
-- 
1.8.3.1