KVM test: timedrift: Use helper functions to make the code more readable
1. As suggested by Yolkfull Chow, use a get_time() helper function that returns
the current host and guest times.
2. Use helper functions that set and restore the CPU affinity of a process.
3. In these helper functions, set the affinity of all threads of the process,
not just the main thread.
Signed-off-by: Michael Goldish <mgoldish@redhat.com>
git-svn-id: http://test.kernel.org/svn/autotest/trunk@3514 592f7852-d20e-0410-864c-8624ca9c26a4
diff --git a/client/tests/kvm/kvm_tests.py b/client/tests/kvm/kvm_tests.py
index 9784ec9..5cdb3dd 100644
--- a/client/tests/kvm/kvm_tests.py
+++ b/client/tests/kvm/kvm_tests.py
@@ -606,6 +606,45 @@
@param params: Dictionary with test parameters.
@param env: Dictionary with the test environment.
"""
+ # Helper functions
+ def set_cpu_affinity(pid, mask):
+ """
+ Set the CPU affinity of all threads of the process with PID pid.
+
+ @param pid: The process ID.
+ @param mask: The CPU affinity mask.
+ @return: A dict containing the previous mask for each thread.
+ """
+ tids = commands.getoutput("ps -L --pid=%s -o lwp=" % pid).split()
+ prev_masks = {}
+ for tid in tids:
+ prev_mask = commands.getoutput("taskset -p %s" % tid).split()[-1]
+ prev_masks[tid] = prev_mask
+ commands.getoutput("taskset -p %s %s" % (mask, tid))
+ return prev_masks
+
+ def restore_cpu_affinity(prev_masks):
+ """
+ Restore the CPU affinity of several threads.
+
+ @param prev_masks: A dict containing TIDs as keys and masks as values.
+ """
+ for tid, mask in prev_masks.items():
+ commands.getoutput("taskset -p %s %s" % (mask, tid))
+
+ def get_time():
+ """
+ Returns the host time and guest time.
+
+ @return: A tuple containing the host time and guest time.
+ """
+ host_time = time.time()
+ session.sendline(time_command)
+ (match, s) = session.read_up_to_prompt()
+ s = re.findall(time_filter_re, s)[0]
+ guest_time = time.mktime(time.strptime(s, time_format))
+ return (host_time, guest_time)
+
vm = kvm_utils.env_get_vm(env, params.get("main_vm"))
if not vm:
raise error.TestError("VM object not found in environment")
@@ -643,19 +682,12 @@
guest_load_sessions = []
host_load_sessions = []
- # Remember the VM's previous CPU affinity
- prev_cpu_mask = commands.getoutput("taskset -p %s" % vm.get_pid())
- prev_cpu_mask = prev_cpu_mask.split()[-1]
# Set the VM's CPU affinity
- commands.getoutput("taskset -p %s %s" % (cpu_mask, vm.get_pid()))
+ prev_affinity = set_cpu_affinity(vm.get_pid(), cpu_mask)
try:
# Get time before load
- host_time_0 = time.time()
- session.sendline(time_command)
- (match, s) = session.read_up_to_prompt()
- s = re.findall(time_filter_re, s)[0]
- guest_time_0 = time.mktime(time.strptime(s, time_format))
+ (host_time_0, guest_time_0) = get_time()
# Run some load on the guest
logging.info("Starting load on guest...")
@@ -678,22 +710,18 @@
timeout=0.5))
# Set the CPU affinity of the shell running the load process
pid = host_load_sessions[-1].get_shell_pid()
- commands.getoutput("taskset -p %s %s" % (cpu_mask, pid))
+ set_cpu_affinity(pid, cpu_mask)
# Try setting the CPU affinity of the load process itself
pid = host_load_sessions[-1].get_pid()
if pid:
- commands.getoutput("taskset -p %s %s" % (cpu_mask, pid))
+ set_cpu_affinity(pid, cpu_mask)
# Sleep for a while (during load)
logging.info("Sleeping for %s seconds..." % load_duration)
time.sleep(load_duration)
# Get time delta after load
- host_time_1 = time.time()
- session.sendline(time_command)
- (match, s) = session.read_up_to_prompt()
- s = re.findall(time_filter_re, s)[0]
- guest_time_1 = time.mktime(time.strptime(s, time_format))
+ (host_time_1, guest_time_1) = get_time()
# Report results
host_delta = host_time_1 - host_time_0
@@ -706,7 +734,7 @@
finally:
logging.info("Cleaning up...")
# Restore the VM's CPU affinity
- commands.getoutput("taskset -p %s %s" % (prev_cpu_mask, vm.get_pid()))
+ restore_cpu_affinity(prev_affinity)
# Stop the guest load
if guest_load_stop_command:
session.get_command_output(guest_load_stop_command)
@@ -721,11 +749,7 @@
time.sleep(rest_duration)
# Get time after rest
- host_time_2 = time.time()
- session.sendline(time_command)
- (match, s) = session.read_up_to_prompt()
- s = re.findall(time_filter_re, s)[0]
- guest_time_2 = time.mktime(time.strptime(s, time_format))
+ (host_time_2, guest_time_2) = get_time()
# Report results
host_delta_total = host_time_2 - host_time_0