invoke setsid for each job

This should cause each jenkins job to reside in its own session. Linux'
automatic group scheduling should then cause jobs to be scheduled
equally rather than processes. The expected result is that highly
parallel jobs do not slow down single-cpu jobs.

2 files changed, 17 insertions, 1 deletions

diff --git a/bin/common-functions.sh b/bin/common-functions.sh
index 7664337b..fd524d44 100755
--- a/bin/common-functions.sh
+++ b/bin/common-functions.sh
@@ -24,7 +24,7 @@ if [ "${0:0:5}" != "/tmp/" ] ; then
 	#  this hack makes it possible to overwrite long running scripts
 	#  anytime...)
 	echo "$(date) - start running \"$0\" as \"$TTT\" using \"$@\" as arguments."
-	$TTT "$@"
+	/srv/jenkins/bin/setsid.py $TTT "$@"
 	exit $?
 	# cleanup is done automatically via trap
 else
diff --git a/bin/setsid.py b/bin/setsid.py
new file mode 100755
index 00000000..32002ec7
--- /dev/null
+++ b/bin/setsid.py
@@ -0,0 +1,16 @@
+#!/usr/bin/python
+"""backport of util-linux' setsid -w to Debian stable"""
+
+import os
+import sys
+
+if __name__ == "__main__":
+    assert len(sys.argv) > 1
+    pid = os.fork()
+    if pid == 0:
+        os.setsid()
+        os.execvp(sys.argv[1], sys.argv[1:])
+    else:
+        cpid, status = os.wait()
+        assert cpid == pid
+        sys.exit(os.WEXITSTATUS(status))