experiments: allow separate shm dir to be specified

this allows the shared memory regions to be created in /dev/shm/ e.g.
instead of the work dir.

experiments/run.py

@@ -68,6 +68,8 @@ g_env.add_argument('--cpdir', metavar='DIR',  type=str,
         default='./out/', help='Checkpoint directory base')
 g_env.add_argument('--hosts', metavar='JSON_FILE', type=str,
         default=None, help='List of hosts to use (json)')
+g_env.add_argument('--shmdir', metavar='DIR',  type=str,
+        default=None, help='Shared memory directory base (workdir if not set)')
 
 g_par = parser.add_argument_group('Parallel Runtime')
 g_par.add_argument('--parallel', dest='runtime', action='store_const',
@@ -147,6 +149,8 @@ def add_exp(e, run, prereq, create_cp, restore_cp, no_simbricks):
 
     workdir = '%s/%s/%d' % (args.workdir, e.name, run)
     cpdir = '%s/%s/%d' % (args.cpdir, e.name, 0)
+    if args.shmdir is not None:
+        shmdir = '%s/%s/%d' % (args.shmdir, e.name, run)
 
     env = exp.ExpEnv(args.repo, workdir, cpdir)
     env.create_cp = create_cp
@@ -155,6 +159,8 @@ def add_exp(e, run, prereq, create_cp, restore_cp, no_simbricks):
     env.pcap_file = ''
     if args.pcap:
         env.pcap_file = workdir+'/pcap'
+    if args.shmdir is not None:
+        env.shm_base = os.path.abspath(shmdir)
 
     run = runtime.Run(e, run, env, outpath, prereq)
     rt.add_run(run)

experiments/simbricks/experiments.py

@@ -313,6 +313,7 @@ class ExpEnv(object):
         self.repodir = os.path.abspath(repo_path)
         self.workdir = os.path.abspath(workdir)
         self.cpdir = os.path.abspath(cpdir)
+        self.shm_base = self.workdir
         self.qemu_img_path = self.repodir + '/sims/external/qemu/build/qemu-img'
         self.qemu_path = self.repodir + '/sims/external/qemu/build/x86_64-softmmu/qemu-system-x86_64'
         self.qemu_kernel_path = self.repodir + '/images/bzImage'
@@ -339,13 +340,13 @@ class ExpEnv(object):
         return '%s/nic.eth.%s' % (self.workdir, sim.name)
 
     def nic_shm_path(self, sim):
-        return '%s/nic.shm.%s' % (self.workdir, sim.name)
+        return '%s/nic.shm.%s' % (self.shm_base, sim.name)
 
     def n2n_eth_path(self, sim_l, sim_c):
         return '%s/n2n.eth.%s.%s' % (self.workdir, sim_l.name, sim_c.name)
 
     def proxy_shm_path(self, sim):
-        return '%s/proxy.shm.%s' % (self.workdir, sim.name)
+        return '%s/proxy.shm.%s' % (self.shm_base, sim.name)
 
     def gem5_outdir(self, sim):
         return '%s/gem5-out.%s' % (self.workdir, sim.name)

experiments/simbricks/runtime/common.py

@@ -48,6 +48,8 @@ class Run(object):
         await exec.mkdir(self.env.workdir)
         pathlib.Path(self.env.cpdir).mkdir(parents=True, exist_ok=True)
         await exec.mkdir(self.env.cpdir)
+        pathlib.Path(self.env.shm_base).mkdir(parents=True, exist_ok=True)
+        await exec.mkdir(self.env.shm_base)
 
 class Runtime(object):
     def add_run(self, run):