remus: command line switch to enable/disable checkpoint compression

Add a command line switch to remus script that allows the user to
enable or disable checkpoint compression in the libxc code.

Signed-off-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
Acked-by: Brendan Cully <brendan@cs.ubc.ca>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>

tools/python/xen/lowlevel/checkpoint/checkpoint.c

@@ -104,13 +104,14 @@ static PyObject* pycheckpoint_start(PyObject* obj, PyObject* args) {
   PyObject* postcopy_cb = NULL;
   PyObject* checkpoint_cb = NULL;
   unsigned int interval = 0;
+  unsigned int flags = 0;
 
   int fd;
   struct save_callbacks callbacks;
   int rc;
 
-  if (!PyArg_ParseTuple(args, "O|OOOI", &iofile, &suspend_cb, &postcopy_cb,
-                       &checkpoint_cb, &interval))
+  if (!PyArg_ParseTuple(args, "O|OOOII", &iofile, &suspend_cb, &postcopy_cb,
+			&checkpoint_cb, &interval, &flags))
     return NULL;
 
   self->interval = interval;
@@ -160,7 +161,7 @@ static PyObject* pycheckpoint_start(PyObject* obj, PyObject* args) {
   callbacks.data = self;
 
   self->threadstate = PyEval_SaveThread();
-  rc = checkpoint_start(&self->cps, fd, &callbacks);
+  rc = checkpoint_start(&self->cps, fd, &callbacks, flags);
   PyEval_RestoreThread(self->threadstate);
 
   if (rc < 0) {

tools/python/xen/lowlevel/checkpoint/checkpoint.h

@@ -40,13 +40,15 @@ typedef struct {
     timer_t timer;
 } checkpoint_state;
 
+#define CHECKPOINT_FLAGS_COMPRESSION 1
 char* checkpoint_error(checkpoint_state* s);
 
 void checkpoint_init(checkpoint_state* s);
 int checkpoint_open(checkpoint_state* s, unsigned int domid);
 void checkpoint_close(checkpoint_state* s);
 int checkpoint_start(checkpoint_state* s, int fd,
-                    struct save_callbacks* callbacks);
+		     struct save_callbacks* callbacks,
+		     unsigned int remus_flags);
 int checkpoint_suspend(checkpoint_state* s);
 int checkpoint_resume(checkpoint_state* s);
 int checkpoint_postflush(checkpoint_state* s);

tools/python/xen/lowlevel/checkpoint/libcheckpoint.c

@@ -170,7 +170,8 @@ static int noop_switch_logdirty(int domid, unsigned enable, void *data)
 }
 
 int checkpoint_start(checkpoint_state* s, int fd,
-                    struct save_callbacks* callbacks)
+		     struct save_callbacks* callbacks,
+		     unsigned int remus_flags)
 {
     int hvm, rc;
     int flags = XCFLAGS_LIVE;
@@ -188,6 +189,8 @@ int checkpoint_start(checkpoint_state* s, int fd,
        if (switch_qemu_logdirty(s, 1))
            return -1;
     }
+    if (remus_flags & CHECKPOINT_FLAGS_COMPRESSION)
+      flags |= XCFLAGS_CHECKPOINT_COMPRESS;
 
     callbacks->switch_qemu_logdirty = noop_switch_logdirty;
 

tools/python/xen/remus/save.py

@@ -133,7 +133,7 @@ class Keepalive(object):
 
 class Saver(object):
     def __init__(self, domid, fd, suspendcb=None, resumecb=None,
-                 checkpointcb=None, interval=0):
+                 checkpointcb=None, interval=0, flags=0):
         """Create a Saver object for taking guest checkpoints.
         domid:        name, number or UUID of a running domain
         fd:           a stream to which checkpoint data will be written.
@@ -141,12 +141,14 @@ class Saver(object):
         resumecb:     callback invoked before guest resumes
         checkpointcb: callback invoked when a checkpoint is complete. Return
                       True to take another checkpoint, or False to stop.
+        flags:        Remus flags to be passed to xc_domain_save
         """
         self.fd = fd
         self.suspendcb = suspendcb
         self.resumecb = resumecb
         self.checkpointcb = checkpointcb
         self.interval = interval
+        self.flags = flags
 
         self.vm = vm.VM(domid)
 
@@ -164,7 +166,8 @@ class Saver(object):
             try:
                 self.checkpointer.open(self.vm.domid)
                 self.checkpointer.start(self.fd, self.suspendcb, self.resumecb,
-                                        self.checkpointcb, self.interval)
+                                        self.checkpointcb, self.interval,
+                                        self.flags)
             except xen.lowlevel.checkpoint.error, e:
                 raise CheckpointError(e)
         finally:

tools/remus/remus

@@ -16,6 +16,9 @@ from xen.xend import XendOptions
 class CfgException(Exception): pass
 
 class Cfg(object):
+
+    REMUS_FLAGS_COMPRESSION = 1
+
     def __init__(self):
         # must be set
         self.domid = 0
@@ -25,6 +28,7 @@ class Cfg(object):
         self.port = XendOptions.instance().get_xend_relocation_port()
         self.interval = 200
         self.netbuffer = True
+        self.flags = self.REMUS_FLAGS_COMPRESSION
         self.timer = False
 
         parser = optparse.OptionParser()
@@ -38,6 +42,8 @@ class Cfg(object):
                           help='replicate to /dev/null (no disk checkpoints, only memory & net buffering)')
         parser.add_option('', '--no-net', dest='nonet', action='store_true',
                           help='run without net buffering (benchmark option)')
+        parser.add_option('', '--no-compression', dest='nocompress', action='store_true',
+                          help='run without checkpoint compression')
         parser.add_option('', '--timer', dest='timer', action='store_true',
                           help='force pause at checkpoint interval (experimental)')
         self.parser = parser
@@ -56,6 +62,8 @@ class Cfg(object):
             self.nullremus = True
         if opts.nonet:
             self.netbuffer = False
+        if opts.nocompress:
+            self.flags &= ~self.REMUS_FLAGS_COMPRESSION
         if opts.timer:
             self.timer = True
 
@@ -190,7 +198,7 @@ def run(cfg):
     rc = 0
 
     checkpointer = save.Saver(cfg.domid, fd, postsuspend, preresume, commit,
-                              interval)
+                              interval, cfg.flags)
 
     try:
         checkpointer.start()