Remove old joined script

python/mlx/_distributed_utils/common.py

@@ -1,5 +1,6 @@
 # Copyright © 2025 Apple Inc.
 
+import argparse
 import ipaddress
 import json
 import sys
@@ -16,6 +17,14 @@ class Host:
     rdma: list[Optional[str]]
 
 
+class OptionalBoolAction(argparse.Action):
+    def __call__(self, parser, namespace, values, option_string=None):
+        if option_string.startswith("--no-"):
+            setattr(namespace, self.dest, False)
+        else:
+            setattr(namespace, self.dest, True)
+
+
 def positive_number(x):
     x = int(x)
     if x <= 0:
@@ -26,6 +35,7 @@ def positive_number(x):
 def log(verbose, *args, **kwargs):
     if not verbose:
         return
+    kwargs["file"] = sys.stderr
     print("\033[32m[INFO]", *args, "\033[0m", **kwargs)
 
 
@@ -50,7 +60,7 @@ def parse_hostlist(parser, hostlist, repeats):
         except ValueError:
             ips = []
         for i in range(repeats):
-            hosts.append(Host(i, h, ips))
+            hosts.append(Host(i, h, ips, []))
     return hosts
 
 

python/mlx/_distributed_utils/config.py

@@ -0,0 +1,568 @@
+# Copyright © 2025 Apple Inc.
+
+import argparse
+import json
+import shlex
+import sys
+import threading
+from collections import defaultdict
+from dataclasses import dataclass
+from subprocess import DEVNULL, run
+from typing import Optional
+
+import mlx.core as mx
+
+from .common import (
+    Host,
+    OptionalBoolAction,
+    log,
+    log_error,
+    parse_hostfile,
+    parse_hostlist,
+)
+
+
+@dataclass
+class SSHInfo:
+    can_ssh: bool
+    has_sudo: bool
+
+    def __bool__(self):
+        return self.can_ssh
+
+
+@dataclass
+class ThunderboltPort:
+    iface: str
+    uuid: str
+    connected_to: Optional[str]
+
+
+@dataclass
+class ThunderboltHost:
+    name: str
+    ports: list[ThunderboltPort]
+
+
+def add_ethernet_ips(hosts, verbose=False):
+    # Get the ips for each host
+    for h in hosts:
+        log(verbose, "Getting the ip from", h.ssh_hostname)
+        h.ips.append(
+            run(
+                ["ssh", h.ssh_hostname, "ipconfig", "getifaddr", "en0"],
+                capture_output=True,
+                text=True,
+            ).stdout.strip()
+        )
+
+
+def check_rdma(hosts, verbose=False):
+    # Check whether the hosts are capable of RDMA over thunderbolt
+    warn = False
+    for h in hosts:
+        log(verbose, "Checking that", h.ssh_hostname, "supports RDMA")
+        rdma_devs = (
+            run(["ssh", h.ssh_hostname, "ibv_devices"], capture_output=True, text=True)
+            .stdout.strip()
+            .split()
+        )
+        rdma_devs = [d for d in rdma_devs if d.startswith("rdma_")]
+        if not rdma_devs:
+            log_warning(h.ssh_hostname, "does not seem to have RDMA enabled")
+            warn = True
+
+    if warn:
+        log_warning()
+        log_warning(
+            "Some of the hosts don't have RDMA enabled or they don't support RDMA."
+        )
+        log_warning()
+        log_warning(
+            "See https://ml-explore.github.io/mlx/build/html/usage/distributed.html"
+        )
+        log_warning("for instructions on how to enable RDMA.")
+
+
+def can_auto_setup(hosts, sshinfo, auto_setup=False):
+    has_sudo = all(info.has_sudo for info in sshinfo)
+    if not has_sudo and auto_setup:
+        log_warning(
+            "Automatic setup requested but the following hosts do not have passwordless sudo"
+        )
+        for h, i in zip(hosts, sshinfo):
+            if not i.has_sudo:
+                log_warning(" - ", h.ssh_hostname)
+    return has_sudo
+
+
+class IPConfigurator:
+    def __init__(self, hosts, tb_hosts, uuid_reverse_index):
+        assigned = set()
+        ips = defaultdict(list)
+        ip0 = 0
+        ip1 = 0
+        for src_node, h in enumerate(tb_hosts):
+            for src_port, p in enumerate(h.ports):
+                if not p.connected_to:
+                    continue
+                if (src_node, src_port) in assigned:
+                    continue
+
+                dst_node, dst_port = uuid_reverse_index[p.connected_to]
+
+                ip_src = f"192.168.{ip0}.{ip1 + 1}"
+                ip_dst = f"192.168.{ip0}.{ip1 + 2}"
+                iface_src = p.iface
+                iface_dst = tb_hosts[dst_node].ports[dst_port].iface
+
+                ips[src_node, dst_node].append((iface_src, ip_src))
+                ips[dst_node, src_node].append((iface_dst, ip_dst))
+
+                assigned.add((src_node, src_port))
+                assigned.add((dst_node, dst_port))
+
+                ip1 += 4
+                if ip1 > 255:
+                    ip0 += 1
+                    ip1 = 0
+                if ip0 > 255:
+                    raise ValueError("Ran out of available local IPs")
+
+        self.ips = ips
+        self.hosts = hosts
+        self.tb_hosts = tb_hosts
+
+    def setup(self, verbose=False, auto_setup=False):
+        netmask = "255.255.255.252"
+        for i, (h, th) in enumerate(zip(self.hosts, self.tb_hosts)):
+            command = ""
+            command += "sudo ifconfig bridge0 down\n"
+            for j in range(len(self.hosts)):
+                if i == j or (i, j) not in self.ips:
+                    continue
+                for (iface, ip), (_, peer) in zip(self.ips[i, j], self.ips[j, i]):
+                    command += f"sudo ifconfig {iface} inet {ip} netmask {netmask}\n"
+                    command += f"sudo route change {peer} -interface {iface}\n"
+            if auto_setup:
+                print(f"Running auto setup for {h.ssh_hostname}")
+                command = command.strip().replace("\n", " ; ")
+                command = ["ssh", h.ssh_hostname, command]
+                log(verbose, shlex.join(command))
+                run(command)
+            else:
+                msg = f"Setup for {h.ssh_hostname}"
+                print(msg)
+                print("=" * len(msg))
+                print(command)
+                input("Enter to continue")
+            print()
+
+
+def parse_hardware_ports(ports_string):
+    ports = {}
+    port_name = None
+    for l in ports_string.decode("utf-8").split("\n"):
+        if l.startswith("Hardware Port:"):
+            port_name = l.strip()[15:]
+        elif l.startswith("Device:"):
+            ports[port_name] = l.strip()[8:]
+            port_name = None
+    return ports
+
+
+def extract_connectivity(hosts, verbose):
+    # Extract the current connectivity from the remote hosts
+    thunderbolt_connections = []
+    for h in hosts:
+        log(verbose, "Getting connectivity from", h.ssh_hostname)
+        thunderbolt_connections.append(
+            json.loads(
+                run(
+                    [
+                        "ssh",
+                        h.ssh_hostname,
+                        "system_profiler",
+                        "SPThunderboltDataType",
+                        "-json",
+                    ],
+                    capture_output=True,
+                ).stdout
+            )
+        )
+    interface_maps = []
+    for h in hosts:
+        log(verbose, "Getting interface names from", h.ssh_hostname)
+        interface_maps.append(
+            parse_hardware_ports(
+                run(
+                    [
+                        "ssh",
+                        h.ssh_hostname,
+                        "networksetup",
+                        "-listallhardwareports",
+                    ],
+                    capture_output=True,
+                ).stdout
+            )
+        )
+
+    # Parse the connectivity into some simple dataclasses
+    tb_hosts = []
+    for c, iface_map in zip(thunderbolt_connections, interface_maps):
+        name = ""
+        ports = []
+        for t in c["SPThunderboltDataType"]:
+            uuid = t.get("domain_uuid_key")
+            if uuid is None:
+                continue
+            name = t["device_name_key"]
+            tag = t["receptacle_1_tag"]["receptacle_id_key"]
+            items = t.get("_items", [])
+            connected_items = [item for item in items if "domain_uuid_key" in item]
+            connected_to = (
+                connected_items[0]["domain_uuid_key"] if connected_items else None
+            )
+            iface = iface_map[f"Thunderbolt {tag}"]
+            ports.append(ThunderboltPort(iface, uuid, connected_to))
+        tb_hosts.append(ThunderboltHost(name, sorted(ports, key=lambda x: x.iface)))
+
+    # Create a reverse index to be able to map uuids to (host, port) quickly
+    uuid_reverse_index = {}
+    for i, h in enumerate(tb_hosts):
+        for j, p in enumerate(h.ports):
+            uuid_reverse_index[p.uuid] = (i, j)
+
+    return tb_hosts, uuid_reverse_index
+
+
+def make_connectivity_matrix(tb_hosts, uuid_reverse_index):
+    connectivity = []
+    for i, h in enumerate(tb_hosts):
+        c = [0] * len(tb_hosts)
+        for p in h.ports:
+            if p.connected_to is not None:
+                j, _ = uuid_reverse_index[p.connected_to]
+                c[j] += 1
+        connectivity.append(c)
+    return connectivity
+
+
+def tb_connectivity_to_dot(hosts, tb_hosts, uuid_reverse_index):
+    # Make ids per node
+    names = []
+    for i in range(len(tb_hosts)):
+        n = ""
+        j = i
+        while True:
+            n += chr(97 + j % 26)
+            j //= 26
+            if j == 0:
+                break
+        names.append(n)
+
+    print("graph G {")
+    print("  node [shape=rectangle];")
+    for i, h in enumerate(hosts):
+        print(f'  {names[i]} [label="{h.ssh_hostname}"];')
+    for i, h in enumerate(tb_hosts):
+        for p in h.ports:
+            if not p.connected_to:
+                continue
+            dst = uuid_reverse_index[p.connected_to]
+            if dst[0] < i:
+                continue
+            print(f"  {names[i]} -- {names[dst[0]]}", end="")
+            print(f' [label="{p.iface}/{tb_hosts[dst[0]].ports[dst[1]].iface}"]')
+    print("}")
+
+
+def extract_rings(connectivity):
+    rings = []
+    existing_rings = set()
+    num_nodes = len(connectivity)
+
+    def dfs(start_node, node, path, visited):
+        path.append(node)
+        visited.add(node)
+        for j in range(num_nodes):
+            if connectivity[node][j] <= 0:
+                continue
+            if j == start_node:
+                yield path[:]
+            if j not in visited:
+                yield from dfs(start_node, j, path, visited)
+        path.pop()
+        visited.remove(node)
+
+    for start in range(num_nodes):
+        for r in dfs(start, start, [], set()):
+            cnt = min(connectivity[r[i]][r[(i + 1) % len(r)]] for i in range(len(r)))
+            rkey = tuple(sorted(r))
+            if rkey not in existing_rings:
+                rings.append((r, cnt))
+                existing_rings.add(rkey)
+
+    return sorted(rings, key=lambda x: -len(x[0]))
+
+
+def check_valid_mesh(hosts, connectivity, strict=True):
+    num_nodes = len(connectivity)
+    for i in range(num_nodes):
+        for j in range(num_nodes):
+            if i == j:
+                continue
+            if connectivity[i][j] <= 0:
+                if strict:
+                    log_error(
+                        f"Incomplete mesh, {hosts[i].ssh_hostname} is not connected to {hosts[j].ssh_hostname}"
+                    )
+                    log_error()
+                    log_error("Try passing --dot to visualize the connectivity")
+                    sys.exit(1)
+                else:
+                    return False
+    return True
+
+
+def check_ssh_connections(hosts):
+    results = [None] * len(hosts)
+
+    def _check(hostname, i):
+        info = SSHInfo(False, False)
+        results[i] = info
+
+        # Check for ssh
+        result = run(
+            [
+                "ssh",
+                "-o",
+                "BatchMode=yes",
+                "-o",
+                "ConnectTimeout=5",
+                hostname,
+                "echo",
+                "success",
+            ],
+            stdout=DEVNULL,
+            stderr=DEVNULL,
+        )
+        info.can_ssh = result.returncode == 0
+        if not info.can_ssh:
+            return
+
+        # Check for sudo
+        result = run(
+            [
+                "ssh",
+                "-o",
+                "BatchMode=yes",
+                "-o",
+                "ConnectTimeout=5",
+                hostname,
+                "sudo",
+                "ls",
+            ],
+            stdout=DEVNULL,
+            stderr=DEVNULL,
+        )
+        info.has_sudo = result.returncode == 0
+
+    threads = [
+        threading.Thread(target=_check, args=(h.ssh_hostname, i))
+        for i, h in enumerate(hosts)
+    ]
+    for t in threads:
+        t.start()
+    for t in threads:
+        t.join()
+
+    if not all(results):
+        log_error("Could not ssh to the following hosts:")
+        for i, h in enumerate(hosts):
+            if not results[i]:
+                log_error("  - ", h.ssh_hostname)
+        log_error()
+        log_error("Maybe they are not set-up for password-less ssh?")
+        sys.exit(1)
+
+    return results
+
+
+def prepare_ethernet_hostfile(args, hosts):
+    log(args.verbose, f"Preparing an ethernet hostfile")
+    add_ethernet_ips(hosts, args.verbose)
+
+    hostfile = []
+    for h in hosts:
+        hostfile.append(dict(ssh=h.ssh_hostname, ips=h.ips))
+
+    if args.output_hostfile:
+        with open(args.output_hostfile, "w") as f:
+            json.dump(hostfile, f, indent=4)
+    else:
+        print("Hostfile")
+        print("========")
+        print(json.dumps(hostfile, indent=4))
+
+
+def configure_ring(args, hosts, ips, ring, sshinfo):
+    log(args.verbose, "Prepare a ring hostfile")
+    ring, count = ring
+    hostfile = []
+    for i, node in enumerate(ring):
+        h = hosts[node]
+        peer = ring[i - 1]
+        hostfile.append(
+            {
+                "ssh": h.ssh_hostname,
+                "ips": [ips.ips[node, peer][c][1] for c in range(count)],
+                "rdma": [],
+            }
+        )
+
+    has_sudo = can_auto_setup(hosts, sshinfo, args.auto_setup)
+    ips.setup(verbose=args.verbose, auto_setup=args.auto_setup and has_sudo)
+
+    if args.output_hostfile:
+        with open(args.output_hostfile, "w") as f:
+            json.dump(hostfile, f, indent=4)
+    else:
+        print("Hostfile")
+        print("========")
+        print(json.dumps(hostfile, indent=4))
+
+
+def configure_jaccl(args, hosts, ips, sshinfo):
+    log(args.verbose, "Prepare a jaccl hostfile")
+    check_rdma(hosts, args.verbose)
+    add_ethernet_ips(hosts, args.verbose)
+
+    hostfile = []
+    for i, h in enumerate(hosts):
+        rdma = []
+        for j in range(len(hosts)):
+            if i == j:
+                rdma.append(None)
+            else:
+                rdma.append(f"rdma_{ips.ips[i, j][0][0]}")
+        hostfile.append({"ssh": h.ssh_hostname, "ips": h.ips, "rdma": rdma})
+
+    has_sudo = can_auto_setup(hosts, sshinfo, args.auto_setup)
+    ips.setup(verbose=args.verbose, auto_setup=args.auto_setup and has_sudo)
+
+    if args.output_hostfile:
+        with open(args.output_hostfile, "w") as f:
+            json.dump(hostfile, f, indent=4)
+    else:
+        print("Hostfile")
+        print("========")
+        print(json.dumps(hostfile, indent=4))
+
+
+def prepare_tb_hostfile(args, hosts, sshinfo):
+    log(args.verbose, f"Preparing for communication over thunderbolt")
+    tb_hosts, uuid_reverse_index = extract_connectivity(hosts, args.verbose)
+
+    if args.dot:
+        tb_connectivity_to_dot(hosts, tb_hosts, uuid_reverse_index)
+        return
+
+    ips = IPConfigurator(hosts, tb_hosts, uuid_reverse_index)
+    connectivity = make_connectivity_matrix(tb_hosts, uuid_reverse_index)
+
+    if args.backend is None:
+        rings = extract_rings(connectivity)
+        has_mesh = check_valid_mesh(hosts, connectivity, False)
+        has_ring = len(rings) > 0 and len(rings[0][0]) == len(hosts)
+
+        if not has_ring and not has_mesh:
+            log_error("Neither thunderbolt mesh nor ring found.")
+            log_error("Perhaps run with --dot to generate a plot of the connectivity.")
+            sys.exit(1)
+
+        elif has_ring:
+            configure_ring(args, hosts, ips, rings[0], sshinfo)
+
+        else:
+            configure_jaccl(args, hosts, ips, sshinfo)
+
+    elif args.backend == "ring":
+        rings = extract_rings(connectivity)
+        has_ring = len(rings) > 0 and len(rings[0][0]) == len(hosts)
+        if not has_ring:
+            log_error("Could not find a full ring.")
+            log_error()
+            log_error("Try passing --dot to visualize the connectivity")
+            if len(rings) > 0:
+                log_error("Rings found:")
+                for r in rings:
+                    log_error(f" - {','.join(hosts[i].ssh_hostname for i in r)}")
+            sys.exit(1)
+        configure_ring(args, hosts, ips, rings[0], sshinfo)
+
+    elif args.backend == "jaccl":
+        check_valid_mesh(hosts, connectivity)
+        configure_jaccl(args, hosts, ips, sshinfo)
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Configure remote machines for use with MLX distributed"
+    )
+    parser.add_argument(
+        "--verbose", action="store_true", help="Print debug messages in stdout"
+    )
+    parser.add_argument(
+        "--hosts", default="127.0.0.1", help="A comma separated list of hosts"
+    )
+    parser.add_argument("--hostfile", help="The file containing the hosts")
+    parser.add_argument(
+        "--over",
+        choices=["thunderbolt", "ethernet"],
+        default="thunderbolt",
+        help="What type of connectivity to configure",
+        required=True,
+    )
+    parser.add_argument(
+        "--output-hostfile", help="If provided, save the hostfile to this path"
+    )
+    parser.add_argument(
+        "--auto-setup",
+        "--no-auto-setup",
+        action=OptionalBoolAction,
+        nargs=0,
+        dest="auto_setup",
+        default=None,
+    )
+    parser.add_argument(
+        "--dot", action="store_true", help="Output the topology in DOT format and exit"
+    )
+    parser.add_argument(
+        "--backend",
+        choices=["ring", "jaccl"],
+        default=None,
+        help="Which distributed backend to configure",
+    )
+    args = parser.parse_args()
+
+    if args.hostfile is not None:
+        hosts = parse_hostfile(parser, args.hostfile)
+    else:
+        hosts = parse_hostlist(parser, args.hosts, 1)
+
+    # Check that we can ssh
+    log(
+        args.verbose,
+        f"Checking for ssh access for {', '.join(h.ssh_hostname for h in hosts)}",
+    )
+    sshinfo = check_ssh_connections(hosts)
+
+    # Prepare a hostfile for communication over ethernet using the ips of the
+    # provided hostnames
+    if args.over == "ethernet":
+        prepare_ethernet_hostfile(args, hosts)
+
+    # Configure the macs for communication over thunderbolt, both via RDMA and IP
+    else:
+        prepare_tb_hostfile(args, hosts, sshinfo)

python/mlx/_distributed_utils/distributed_run.py

@@ -1,911 +0,0 @@
-# Copyright © 2025 Apple Inc.
-
-import argparse
-import base64
-import ipaddress
-import json
-import os
-import platform
-import shlex
-import shutil
-import sys
-import tempfile
-import threading
-import time
-from collections import Counter
-from dataclasses import dataclass
-from pathlib import Path
-from queue import Empty as QueueEmpty
-from queue import Queue
-from select import select
-from subprocess import PIPE, Popen, run
-from typing import Optional
-
-import mlx.core as mx
-
-
-@dataclass
-class Host:
-    rank: int
-    ssh_hostname: str
-    ips: list[str]
-
-
-@dataclass
-class ThunderboltPort:
-    iface: str
-    uuid: str
-    connected_to: Optional[str]
-
-
-@dataclass
-class ThunderboltHost:
-    name: str
-    ports: list[ThunderboltPort]
-
-
-def parse_hardware_ports(ports_string):
-    ports = {}
-    port_name = None
-    for l in ports_string.decode("utf-8").split("\n"):
-        if l.startswith("Hardware Port:"):
-            port_name = l.strip()[15:]
-        elif l.startswith("Device:"):
-            ports[port_name] = l.strip()[8:]
-            port_name = None
-    return ports
-
-
-def get_num_nvidia_gpus():
-    result = run(["nvidia-smi", "-L"], capture_output=True, text=True, check=True)
-    return len(result.stdout.strip().split("\n"))
-
-
-def extract_rings(hosts, index):
-    def usable_port(i, j, used_ports):
-        return (i, j) not in used_ports and hosts[i].ports[j].connected_to is not None
-
-    def dfs(start_node, node, path, visited, used_ports):
-        path.append(node)
-        visited.add(node)
-        for j, p in enumerate(hosts[node].ports):
-            if not usable_port(node, j, used_ports):
-                continue
-            next_node, _ = index[p.connected_to]
-            if next_node == start_node:
-                yield path[:]
-            if next_node not in visited:
-                yield from dfs(start_node, next_node, path, visited, used_ports)
-        path.pop()
-        visited.remove(node)
-
-    # Concretize maps the found cycle to real thunderbolt ports. It also adds
-    # those ports to the used set so next cycles can't use them again.
-    def concretize(cycle, used_ports):
-        concrete_path = []
-        for n1, n2 in zip(cycle, cycle[1:] + cycle[:1]):
-            for j, p in enumerate(hosts[n1].ports):
-                if not usable_port(n1, j, used_ports):
-                    continue
-                n2_hat, nj = index[p.connected_to]
-                if n2 == n2_hat:
-                    concrete_path.append(((n1, j), (n2, nj)))
-                    used_ports.add((n1, j))
-                    used_ports.add((n2, nj))
-                    break
-            if concrete_path[-1][0][0] != n1:
-                raise RuntimeError("Couldn't concretize the cycle")
-        return concrete_path
-
-    # Normalize tries to ensure that the cycles have the same direction so we can
-    # use them together. We achieve this by selecting the direction such that
-    # the smallest rank hosts connect to larger rank hosts.
-    def normalize(path):
-        small_to_large = sum(1 for p in path if p[0][0] < p[1][0])
-        if small_to_large > len(path) - small_to_large:
-            return path
-        else:
-            return [(p[1], p[0]) for p in path]
-
-    rings = []
-    used_ports = set()
-    for start_node in range(len(hosts)):
-        while True:
-            ring = []
-            for r in dfs(start_node, start_node, [], set(), used_ports):
-                if len(r) > len(ring):
-                    ring = r
-                # Break early since we won't find a bigger ring no matter what
-                if len(ring) == len(hosts):
-                    break
-            if not ring:
-                break
-            try:
-                rings.append(normalize(concretize(ring, used_ports)))
-            except RuntimeError:
-                if len(rings) > 0:
-                    return rings
-                raise
-
-    return rings
-
-
-def positive_number(x):
-    x = int(x)
-    if x <= 0:
-        raise ValueError("Number should be positive")
-    return x
-
-
-def log(verbose, *args, **kwargs):
-    if not verbose:
-        return
-    print("\033[32m[INFO]", *args, "\033[0m", **kwargs)
-
-
-def log_warning(*args, **kwargs):
-    kwargs["file"] = sys.stderr
-    print("\033[33m[WARN]", *args, "\033[0m", **kwargs)
-
-
-def log_error(*args, **kwargs):
-    kwargs["file"] = sys.stderr
-    print("\033[31m[ERROR]", *args, "\033[0m", **kwargs)
-
-
-def parse_hostfile(parser, hostfile):
-    """Parse the json hostfile that contains both the hostnames to ssh into and
-    the ips to communicate over when using the ring backend.
-
-    Example:
-
-        [
-            {"ssh": "hostname1", "ips": ["123.123.123.1"]},
-            {"ssh": "hostname2", "ips": ["123.123.123.2"]},
-            ...
-            {"ssh": "hostnameN", "ips": ["123.123.123.N"]},
-        ]
-
-    Args:
-        hostfile (str): The path to the json file containing the host
-            information
-    """
-    hostfile = Path(hostfile)
-    if not hostfile.exists():
-        parser.error(f"Hostfile {str(hostfile)} doesn't exist")
-
-    try:
-        hosts = []
-        with open(hostfile) as f:
-            for i, h in enumerate(json.load(f)):
-                hosts.append(Host(i, h["ssh"], h.get("ips", [])))
-        return hosts
-    except Exception as e:
-        parser.error(f"Failed to parse hostfile {str(hostfile)} ({str(e)})")
-
-
-def parse_hostlist(parser, hostlist, repeats):
-    hosts = []
-    for i, h in enumerate(hostlist.split(",")):
-        if h == "":
-            raise ValueError("Hostname cannot be empty")
-        try:
-            ipaddress.ip_address(h)
-            ips = [h]
-        except ValueError:
-            ips = []
-        for i in range(repeats):
-            hosts.append(Host(i, h, ips))
-    return hosts
-
-
-def make_monitor_script(rank, hostfile, cwd, env, command, verbose):
-    # Imports that are used throughout
-    script = ""
-    script += "import os\n"
-    script += "import sys\n"
-    script += "import tempfile\n"
-    script += "from pathlib import Path\n"
-
-    # Write the PID to a file so we can kill the process if needed
-    script += "_, pidfile = tempfile.mkstemp() \n"
-    script += "open(pidfile, 'w').write(str(os.getpid()))\n"
-    script += "print(pidfile, flush=True)\n"
-
-    # Change the working directory if one was requested. Otherwise attempt to
-    # change to the current one but don't fail if it wasn't possible.
-    d = cwd or os.getcwd()
-    script += f"if Path({repr(d)}).exists():\n"
-    script += f"    os.chdir({repr(d)})\n"
-    if cwd is not None:
-        script += "else:\n"
-        script += (
-            f"    print('Failed to change directory to', {repr(d)}, file=sys.stderr)\n"
-        )
-        script += f"    sys.exit(1)\n"
-
-    # Add the environment variables that were given to us
-    script += "env = dict(os.environ)\n"
-    for e in env:
-        key, *value = e.split("=", maxsplit=1)
-        value = shlex.quote(value[0]) if len(value) > 0 else ""
-        if not all(c.isalnum() or c == "_" for c in key):
-            log_warning(f"'{e}' is an invalid environment variable so it is ignored")
-            continue
-        script += f"env[{repr(key)}] = {repr(value)}\n"
-
-    # Add the environment variables to enable the ring distributed backend
-    if hostfile != "":
-        script += "_, hostfile = tempfile.mkstemp()\n"
-        script += "with open(hostfile, 'w') as f:\n"
-        script += f"    f.write({repr(hostfile)})\n"
-        if verbose:
-            script += "env['MLX_RING_VERBOSE'] = '1'\n"
-        script += "env['MLX_HOSTFILE'] = hostfile\n"
-        script += f"env['MLX_RANK'] = '{rank}'\n"
-        script += "\n"
-
-    # Replace the process with the script
-    script += f"command = [{','.join(map(repr, command))}]\n"
-    script += "os.execve(command[0], command, env)\n"
-
-    return script
-
-
-def launch_ring(parser, hosts, args, command):
-    stop = False
-    exit_codes = [None] * len(hosts)
-
-    def node_thread(rank, host, hostfile, input_queue):
-        is_local = host == "127.0.0.1"
-        script = make_monitor_script(
-            rank, hostfile, args.cwd, args.env, command, args.verbose
-        )
-        script_b64 = base64.b64encode(script.encode()).decode()
-        cmd = f'{sys.executable} -c "import base64; exec(base64.b64decode(\\"{script_b64}\\"));"'
-        if not is_local:
-            cmd = f"ssh {host} '{cmd}'"
-        p = Popen(
-            cmd,
-            shell=True,
-            stdin=PIPE,
-            stdout=PIPE,
-            stderr=PIPE,
-        )
-        os.set_blocking(p.stdout.fileno(), False)
-        os.set_blocking(p.stderr.fileno(), False)
-        os.set_blocking(p.stdin.fileno(), False)
-
-        # Repeat the stdout and stderr to the local machine
-        to_read = [p.stdout.fileno(), p.stderr.fileno()]
-        to_write = [p.stdin.fileno(), sys.stdout.fileno(), sys.stderr.fileno()]
-        pidfile = ""
-        stdin_buffer = b""
-        stdout_buffer = b""
-        stderr_buffer = b""
-        while p.poll() is None:
-            try:
-                stdin_buffer += input_queue.get_nowait()
-            except QueueEmpty:
-                pass
-            rlist, wlist, _ = select(to_read, to_write, [], 1.0)
-            for fd in rlist:
-                msg = os.read(fd, 8192).decode(errors="ignore")
-
-                # Fetch the PID file first if we haven't already
-                if pidfile == "":
-                    pidfile, *msg = msg.split("\n", maxsplit=1)
-                    msg = msg[0] if msg else ""
-
-                is_stdout = fd == p.stdout.fileno()
-                if is_stdout:
-                    stdout_buffer += msg.encode()
-                else:
-                    stderr_buffer += msg.encode()
-            for fd in wlist:
-                if fd == p.stdin.fileno() and len(stdin_buffer) > 0:
-                    n = os.write(fd, stdin_buffer)
-                    stdin_buffer = stdin_buffer[n:]
-                elif fd == sys.stdout.fileno() and len(stdout_buffer) > 0:
-                    n = os.write(fd, stdout_buffer)
-                    stdout_buffer = stdout_buffer[n:]
-                elif fd == sys.stderr.fileno() and len(stderr_buffer) > 0:
-                    n = os.write(fd, stderr_buffer)
-                    stderr_buffer = stderr_buffer[n:]
-            if stop:
-                p.terminate()
-                break
-        p.wait()
-        exit_codes[rank] = p.returncode
-
-        # Kill the remote program if possible
-        cmd = ""
-        cmd += f"pid=$(cat {pidfile}); "
-        cmd += "if ps -p $pid >/dev/null; then "
-        cmd += "    kill $pid; "
-        cmd += "    echo 1; "
-        cmd += "else "
-        cmd += "    echo 0; "
-        cmd += "fi; "
-        cmd += f"rm {pidfile}"
-        if not is_local:
-            cmd = f"ssh {host} '{cmd}'"
-        c = run(cmd, check=True, shell=True, capture_output=True, text=True)
-        if c.stdout.strip() == "1":
-            log_warning(f"Node with rank {rank} was killed")
-        elif p.returncode != 0:
-            log_warning(f"Node with rank {rank} exited with code {p.returncode}")
-        else:
-            log(args.verbose, f"Node with rank {rank} completed")
-
-    if all(len(h.ips) == 0 for h in hosts):
-        parser.error(
-            "The ring backend requires IPs to be provided instead of hostnames"
-        )
-
-    port = args.starting_port
-    ring_hosts = []
-    for h in hosts:
-        node = []
-        for ip in h.ips:
-            for i in range(args.connections_per_ip):
-                node.append(f"{ip}:{port}")
-                port += 1
-        ring_hosts.append(node)
-    hostfile = json.dumps(ring_hosts) if len(ring_hosts) > 1 else ""
-
-    log(args.verbose, "Running", shlex.join(command))
-
-    input_queues = []
-    threads = []
-    for i, h in enumerate(hosts):
-        if i + 1 == len(hosts):
-            time.sleep(1.0)
-        input_queues.append(Queue())
-        t = threading.Thread(
-            target=node_thread, args=(i, h.ssh_hostname, hostfile, input_queues[-1])
-        )
-        t.start()
-        threads.append(t)
-
-    os.set_blocking(sys.stdin.fileno(), False)
-    while not stop:
-        rlist, _, _ = select([sys.stdin.fileno()], [], [], 1.0)
-        for fd in rlist:
-            stdin_buffer = os.read(fd, 8192)
-            for q in input_queues:
-                q.put(stdin_buffer)
-        if any(t.is_alive() for t in threads):
-            for i, t in enumerate(threads):
-                if not t.is_alive():
-                    if exit_codes[i] != 0:
-                        stop = True
-                        break
-        else:
-            break
-    for t in threads:
-        t.join()
-
-
-def get_mpi_libname():
-    try:
-        ompi_info = run(["which", "ompi_info"], check=True, capture_output=True)
-        ompi_info = ompi_info.stdout.strip().decode()
-
-        if platform.system() == "Darwin":
-            otool_output = run(
-                ["otool", "-L", ompi_info], check=True, capture_output=True
-            )
-        else:
-            otool_output = run(["ldd", ompi_info], check=True, capture_output=True)
-        otool_output = otool_output.stdout.decode()
-
-        # StopIteration if not found
-        libmpi_line = next(
-            filter(lambda line: "libmpi" in line, otool_output.splitlines())
-        )
-        return libmpi_line.strip().split()[0].removeprefix("@rpath/")
-    except:
-        return None
-
-
-def launch_mpi(parser, hosts, args, command):
-    mpirun = run(["which", "mpirun"], check=True, capture_output=True)
-    mpirun = mpirun.stdout.strip().decode()
-
-    # Compatibility with homebrew and pip installs
-    mpi_libname = get_mpi_libname()
-    if mpi_libname is not None:
-        dyld = Path(mpirun).parent.parent / "lib"
-        args.env = [
-            f"DYLD_LIBRARY_PATH={str(dyld)}",
-            f"MLX_MPI_LIBNAME={mpi_libname}",
-        ] + args.env
-
-    log(args.verbose, f"Using '{mpirun}'")
-    with tempfile.NamedTemporaryFile(mode="w") as f:
-        hosts = Counter((h.ssh_hostname for h in hosts))
-        for h, n in hosts.items():
-            print(f"{h} slots={n}", file=f)
-        f.flush()
-
-        cmd = [
-            mpirun,
-            "--output",
-            ":raw",  # do not line buffer output
-            "--hostfile",
-            f.name,
-            *(["-cwd", args.cwd] if args.cwd else []),
-            *sum((["-x", e] for e in args.env), []),
-            *sum([shlex.split(arg) for arg in args.mpi_arg], []),
-            "--",
-            *command,
-        ]
-        log(args.verbose, "Running", " ".join(cmd))
-        try:
-            run(cmd)
-        except KeyboardInterrupt:
-            pass
-
-
-def launch_nccl(parser, hosts, args, command):
-    master_host = hosts[0].ips[0]
-
-    if master_host != "127.0.0.1":
-        raise ValueError("The NCCL backend only supports localhost for now.")
-    master_port = args.nccl_port
-    world_size = len(hosts)
-
-    base_env = os.environ.copy()
-    base_env.update(
-        {
-            "NCCL_DEBUG": base_env.get(
-                "NCCL_DEBUG", "INFO" if args.verbose else "DEBUG"
-            ),
-            "NCCL_SOCKET_IFNAME": "lo",  # Use loopback for local communication
-            "NCCL_HOST_IP": master_host,
-            "NCCL_PORT": str(master_port),
-            "MLX_WORLD_SIZE": str(world_size),
-        }
-    )
-    procs = []
-    num_gpus = get_num_nvidia_gpus()
-    if num_gpus == 0:
-        raise RuntimeError("Cannot run NCCL backend with no GPUs.")
-    if args.repeat_hosts > num_gpus:
-        raise RuntimeError("NCCL requires a separate GPU per process.")
-
-    try:
-        for rank in range(world_size):
-            env = base_env.copy()
-            mlx_rank = str(rank % args.repeat_hosts)
-            env["MLX_RANK"] = mlx_rank
-            env["CUDA_VISIBLE_DEVICES"] = mlx_rank
-            p = Popen(command, env=env)
-            procs.append(p)
-
-        for p in procs:
-            ret = p.wait()
-            if ret != 0:
-                raise RuntimeError(f"Rank process exited with {ret}")
-
-    except (RuntimeError, KeyboardInterrupt) as err:
-        for p in procs:
-            if p.poll() is None:
-                try:
-                    p.kill()
-                except Exception:
-                    pass
-        raise
-
-
-def check_ssh_connections(hosts):
-    results = [False] * len(hosts)
-
-    def _check(hostname, i):
-        result = run(
-            [
-                "ssh",
-                "-o",
-                "BatchMode=yes",
-                "-o",
-                "ConnectTimeout=5",
-                hostname,
-                "echo",
-                "success",
-            ],
-            stdout=PIPE,
-            stderr=PIPE,
-        )
-        results[i] = result.returncode == 0
-
-    threads = [
-        threading.Thread(target=_check, args=(h.ssh_hostname, i))
-        for i, h in enumerate(hosts)
-    ]
-    for t in threads:
-        t.start()
-    for t in threads:
-        t.join()
-
-    if not all(results):
-        log_error("Could not ssh to the following hosts:")
-        for i, h in enumerate(hosts):
-            if not results[i]:
-                log_error("  - ", h.ssh_hostname)
-        log_error()
-        log_error("Maybe they are not set-up for password-less ssh?")
-        sys.exit(1)
-
-
-def prepare_tb_ring(args, hosts):
-    log(
-        args.verbose,
-        f"Preparing a thunderbolt ring for {', '.join(h.ssh_hostname for h in hosts)}",
-    )
-
-    # Check that we can ssh
-    check_ssh_connections(hosts)
-    if args.auto_setup and args.verbose:
-        log_warning(
-            "--auto-setup is requested which requires password-less sudo",
-            "on the remote hosts",
-        )
-
-    # Extract the current connectivity from the remote hosts
-    thunderbolt_connections = []
-    for h in hosts:
-        log(args.verbose, "Getting connectivity from", h.ssh_hostname)
-        thunderbolt_connections.append(
-            json.loads(
-                run(
-                    [
-                        "ssh",
-                        h.ssh_hostname,
-                        "system_profiler",
-                        "SPThunderboltDataType",
-                        "-json",
-                    ],
-                    capture_output=True,
-                ).stdout
-            )
-        )
-    interface_maps = []
-    for h in hosts:
-        log(args.verbose, "Getting interface names from", h.ssh_hostname)
-        interface_maps.append(
-            parse_hardware_ports(
-                run(
-                    [
-                        "ssh",
-                        h.ssh_hostname,
-                        "networksetup",
-                        "-listallhardwareports",
-                    ],
-                    capture_output=True,
-                ).stdout
-            )
-        )
-
-    # Parse the connectivity into some simple dataclasses
-    tb_hosts = []
-    for c, iface_map in zip(thunderbolt_connections, interface_maps):
-        name = ""
-        ports = []
-        for t in c["SPThunderboltDataType"]:
-            uuid = t.get("domain_uuid_key")
-            if uuid is None:
-                continue
-            name = t["device_name_key"]
-            tag = t["receptacle_1_tag"]["receptacle_id_key"]
-            items = t.get("_items", [])
-            connected_items = [item for item in items if "domain_uuid_key" in item]
-            connected_to = (
-                connected_items[0]["domain_uuid_key"] if connected_items else None
-            )
-            iface = iface_map[f"Thunderbolt {tag}"]
-            ports.append(ThunderboltPort(iface, uuid, connected_to))
-        tb_hosts.append(ThunderboltHost(name, sorted(ports, key=lambda x: x.iface)))
-
-    # Create a reverse index to be able to map uuids to (host, port) quickly
-    uuid_reverse_index = {}
-    for i, h in enumerate(tb_hosts):
-        for j, p in enumerate(h.ports):
-            uuid_reverse_index[p.uuid] = (i, j)
-
-    # Find the rings by simply walking and marking visited (host, port) tuples
-    # and keeping the largest rings greedily.
-    log(args.verbose, "Extracting rings from the parsed connectivity")
-    rings = extract_rings(tb_hosts, uuid_reverse_index)
-
-    # Just output a DOT graphical representation of the found rings
-    if args.dot:
-        names = []
-        for i in range(len(tb_hosts)):
-            n = ""
-            j = i
-            while True:
-                n += chr(97 + j % 26)
-                j //= 26
-                if j == 0:
-                    break
-            names.append(n)
-
-        print("graph G {")
-        print("  node [shape=rectangle];")
-        for i, h in enumerate(hosts):
-            print(f'  {names[i]} [label="{h.ssh_hostname}"];')
-        for r in rings:
-            for (i, _), (j, _) in r:
-                print(f"  {names[i]} -- {names[j]};")
-        print("}")
-        return
-
-    # Assign IPs to each interface such that the interfaces can communicate
-    ips = {}
-    pairs = {}
-    expecting = set()
-    ip0 = 0
-    ip1 = 0
-    netmask = "255.255.255.252"
-    for r in rings:
-        for a, b in r:
-            ips[a] = f"192.168.{ip0}.{ip1 + 1}"
-            ips[b] = f"192.168.{ip0}.{ip1 + 2}"
-            pairs[a] = b
-            pairs[b] = a
-            expecting.add(b)
-            ip1 += 4
-            if ip1 > 255:
-                ip0 += 1
-                ip1 = 0
-            if ip0 > 255:
-                raise ValueError("Ran out of available local IPs for the ring")
-
-    # Extract the host order from the first ring
-    hostmap = dict((r[0][0], r[1][0]) for r in rings[0])
-    first_host = min(hostmap.keys())
-    order = [first_host]
-    while hostmap[order[-1]] != first_host:
-        order.append(hostmap[order[-1]])
-
-    # Create the hostfile
-    hostfile = []
-    for i in order:
-        h = hosts[i]
-        host = {
-            "ssh": h.ssh_hostname,
-            "ips": [
-                ips[i, j]
-                for j, p in enumerate(tb_hosts[i].ports)
-                if (i, j) in expecting
-            ],
-        }
-        hostfile.append(host)
-
-    if not args.hostfile_only:
-        for i, h in enumerate(hosts):
-            command = ""
-            command += "sudo ifconfig bridge0 down\n"
-            for j, p in enumerate(tb_hosts[i].ports):
-                if (i, j) not in ips:
-                    continue
-                iface = p.iface
-                ip = ips[i, j]
-                peer = ips[pairs[i, j]]
-                command += f"sudo ifconfig {iface} inet {ip} netmask {netmask}\n"
-                command += f"sudo route change {peer} -interface {iface}\n"
-            if args.auto_setup:
-                print(f"Running auto setup for {h.ssh_hostname}")
-                command = command.strip().replace("\n", " && ")
-                command = ["ssh", h.ssh_hostname, command]
-                log(args.verbose, shlex.join(command))
-                run(command)
-            else:
-                msg = f"Setup for {h.ssh_hostname}"
-                print(msg)
-                print("=" * len(msg))
-                print(command)
-                input("Enter to continue")
-            print()
-
-    if args.output_hostfile:
-        with open(args.output_hostfile, "w") as f:
-            json.dump(hostfile, f, indent=4)
-    else:
-        print("Hostfile")
-        print("========")
-        print(json.dumps(hostfile, indent=4))
-
-
-def prepare_hostfile(args, hosts):
-    log(
-        args.verbose,
-        f"Preparing an ethernet hostfile for {', '.join(h.ssh_hostname for h in hosts)}",
-    )
-
-    # Check that we can ssh
-    check_ssh_connections(hosts)
-
-    # Get the ips for each host
-    for h in hosts:
-        log(args.verbose, "Getting the ip from", h.ssh_hostname)
-        h.ips.append(
-            run(
-                ["ssh", h.ssh_hostname, "ipconfig", "getifaddr", "en0"],
-                capture_output=True,
-                text=True,
-            ).stdout.strip()
-        )
-
-    hostfile = []
-    for h in hosts:
-        hostfile.append(dict(ssh=h.ssh_hostname, ips=h.ips))
-
-    if args.output_hostfile:
-        with open(args.output_hostfile, "w") as f:
-            json.dump(hostfile, f, indent=4)
-    else:
-        print("Hostfile")
-        print("========")
-        print(json.dumps(hostfile, indent=4))
-
-
-def distributed_config():
-    parser = argparse.ArgumentParser(
-        description="Configure remote machines for use with MLX distributed"
-    )
-    parser.add_argument(
-        "--verbose", action="store_true", help="Print debug messages in stdout"
-    )
-    parser.add_argument(
-        "--backend",
-        choices=["ring", "mpi", "nccl"],
-        default="nccl" if mx.cuda.is_available() else "ring",
-        help="Which distributed backend to configure",
-    )
-    parser.add_argument(
-        "--over",
-        choices=["thunderbolt", "ethernet"],
-        default="thunderbolt",
-        help="What type of connectivity to configure",
-    )
-    parser.add_argument(
-        "--hosts", default="127.0.0.1", help="A comma separated list of hosts"
-    )
-    parser.add_argument("--hostfile", help="The file containing the hosts")
-    parser.add_argument(
-        "--dot", action="store_true", help="Output the topology in DOT format and exit"
-    )
-    parser.add_argument(
-        "--hostfile-only", action="store_true", help="If set only compute the hostfile"
-    )
-    parser.add_argument(
-        "--output-hostfile", help="If provided, save the hostfile to this path"
-    )
-    parser.add_argument(
-        "--auto-setup",
-        action="store_true",
-        help="If set we will attempt to automatically configure the machines via ssh",
-    )
-    args = parser.parse_args()
-
-    if args.backend == "mpi" and args.over == "thunderbolt":
-        raise ValueError(
-            (
-                "The configuration of MPI over thunderbolt is "
-                "not supported yet by mlx.distributed_config"
-            )
-        )
-
-    if args.hostfile is not None:
-        hosts = parse_hostfile(parser, args.hostfile)
-    else:
-        hosts = parse_hostlist(parser, args.hosts, 1)
-
-    if args.over == "thunderbolt":
-        prepare_tb_ring(args, hosts)
-    else:
-        prepare_hostfile(args, hosts)
-
-
-def main():
-    parser = argparse.ArgumentParser(description="Launch an MLX distributed program")
-    parser.add_argument(
-        "--print-python",
-        action="store_true",
-        help="Print the path to the current python executable and exit",
-    )
-    parser.add_argument(
-        "--verbose", action="store_true", help="Print debug messages in stdout"
-    )
-    parser.add_argument(
-        "--hosts", default="127.0.0.1", help="A comma separated list of hosts"
-    )
-    parser.add_argument(
-        "--repeat-hosts",
-        "-n",
-        type=positive_number,
-        default=1,
-        help="Repeat each host a given number of times",
-    )
-    parser.add_argument("--hostfile", help="The file containing the hosts")
-    parser.add_argument(
-        "--backend",
-        choices=["ring", "mpi", "nccl", "jaccl"],
-        default="nccl" if mx.cuda.is_available() else "ring",
-        help="Which distributed backend to launch",
-    )
-    parser.add_argument(
-        "--env",
-        action="append",
-        default=[],
-        help="Set environment variables for the jobs",
-    )
-    parser.add_argument(
-        "--mpi-arg",
-        action="append",
-        default=[],
-        help="Arguments to pass directly to mpirun",
-    )
-    parser.add_argument(
-        "--connections-per-ip",
-        default=1,
-        type=int,
-        help="How many connections per ip to use for the ring backend",
-    )
-    parser.add_argument(
-        "--starting-port",
-        "-p",
-        type=int,
-        default=5000,
-        help="For the ring backend listen on this port increasing by 1 per rank and IP",
-    )
-    parser.add_argument(
-        "--cwd", help="Set the working directory on each node to the provided one"
-    )
-    parser.add_argument(
-        "--nccl-port",
-        type=int,
-        default=12345,
-        help="The port to use for the NCCL communication (only for nccl backend)",
-    )
-
-    args, rest = parser.parse_known_args()
-
-    if args.print_python:
-        print(sys.executable)
-        return
-
-    if len(rest) == 0:
-        parser.error("No script is provided")
-    if rest[0] == "--":
-        rest.pop(0)
-
-    # Try to extract a list of hosts and corresponding ips
-    if args.hostfile is not None:
-        hosts = parse_hostfile(parser, args.hostfile)
-    else:
-        hosts = parse_hostlist(parser, args.hosts, args.repeat_hosts)
-
-    # Check if the script is a file and convert it to a full path
-    if (script := Path(rest[0])).exists():
-        rest[0:1] = [sys.executable, str(script.resolve())]
-    elif (command := shutil.which(rest[0])) is not None:
-        rest[0] = command
-    else:
-        raise ValueError(f"Invalid script or command {rest[0]}")
-
-    # Launch
-    if args.backend == "ring":
-        launch_ring(parser, hosts, args, rest)
-    if args.backend == "mpi":
-        launch_mpi(parser, hosts, args, rest)
-    if args.backend == "nccl":
-        launch_nccl(parser, hosts, args, rest)
-    if args.backend == "jaccl":
-        launch_jaccl(parser, hosts, args, rest)
-
-
-if __name__ == "__main__":
-    main()

python/mlx/_distributed_utils/launch.py

@@ -45,13 +45,11 @@ class CommandProcess:
 
 
 class RemoteProcess(CommandProcess):
-    def __init__(self, rank, host, cwd, files, env, command):
+    def __init__(self, rank, host, python, cwd, files, env, command):
         is_local = host == "127.0.0.1"
-        script = RemoteProcess.make_monitor_script(rank, cwd, files, env, command)
-        script_b64 = base64.b64encode(script.encode()).decode()
-        cmd = f'{sys.executable} -c "import base64; exec(base64.b64decode(\\"{script_b64}\\"));"'
+        cmd = RemoteProcess.make_launch_script(rank, cwd, files, env, command)
         if not is_local:
-            cmd = f"ssh {host} '{cmd}'"
+            cmd = f"ssh {host} {shlex.quote(cmd)}"
 
         self._host = host
         self._pidfile = None
@@ -90,47 +88,33 @@ class RemoteProcess(CommandProcess):
         self._process.wait()
 
         # Kill the remote program if possible
-        cmd = ""
-        cmd += f"pid=$(cat {self._pidfile}); "
-        cmd += "if ps -p $pid >/dev/null; then "
-        cmd += "    kill $pid; "
-        cmd += "    echo 1; "
-        cmd += "else "
-        cmd += "    echo 0; "
-        cmd += "fi; "
-        cmd += f"rm {self._pidfile}"
+        cmd = RemoteProcess.make_kill_script(self._pidfile)
         if not self._is_local:
-            cmd = f"ssh {self._host} '{cmd}'"
+            cmd = f"ssh {self._host} {shlex.quote(cmd)}"
         c = run(cmd, check=True, shell=True, capture_output=True, text=True)
 
         self._killed = c.stdout.strip() == "1"
 
     @staticmethod
-    def make_monitor_script(rank, cwd, files, env, command):
-        # Imports that are used throughout
+    def make_launch_script(rank, cwd, files, env, command):
         script = ""
-        script += "import os\n"
-        script += "import sys\n"
-        script += "import tempfile\n"
-        script += "from pathlib import Path\n"
 
         # Write the PID to a file so we can kill the process if needed
-        script += "_, pidfile = tempfile.mkstemp() \n"
-        script += "open(pidfile, 'w').write(str(os.getpid()))\n"
-        script += "print(pidfile, flush=True)\n"
+        script += "pidfile=$(mktemp); "
+        script += "echo $$ > $pidfile; "
+        script += "echo $pidfile; "
 
         # Change the working directory if one was requested. Otherwise attempt to
         # change to the current one but don't fail if it wasn't possible.
         d = cwd or os.getcwd()
-        script += f"if Path({repr(d)}).exists():\n"
-        script += f"    os.chdir({repr(d)})\n"
+        script += f"if [[ -d {repr(d)} ]]; then "
+        script += f"  cd {repr(d)}; "
         if cwd is not None:
-            script += "else:\n"
-            script += f"    print('Failed to change directory to', {repr(d)}, file=sys.stderr)\n"
-            script += f"    sys.exit(1)\n"
+            script += "else "
+            script += f" echo 'Failed to change directory to' {repr(d)} >2; "
+        script += "fi; "
 
         # Add the environment variables that were requested
-        script += "env = dict(os.environ)\n"
         for e in env:
             key, *value = e.split("=", maxsplit=1)
             value = shlex.quote(value[0]) if len(value) > 0 else ""
@@ -139,22 +123,34 @@ class RemoteProcess(CommandProcess):
                     f"'{e}' is an invalid environment variable so it is ignored"
                 )
                 continue
-            script += f"env[{repr(key)}] = {repr(value)}\n"
+            script += f"export {key}={value}; "
 
         # Make the temporary files
         for env_name, content in files.items():
-            script += "_, fname = tempfile.mkstemp()\n"
-            script += "with open(fname, 'w') as f:\n"
-            script += f"    f.write({repr(content)})\n"
-            script += f"env[{repr(env_name)}] = fname\n"
+            script += "fname=$(mktemp); "
+            script += f"echo {shlex.quote(content)} >$fname; "
+            script += f"export {env_name}=$fname; "
 
         # Finally add the rank
-        script += f"env['MLX_RANK'] = '{rank}'\n"
-        script += "\n"
+        script += f"export MLX_RANK={rank}; "
 
         # Replace the process with the script
-        script += f"command = [{','.join(map(repr, command))}]\n"
-        script += "os.execve(command[0], command, env)\n"
+        script += f"cmd=({' '.join(map(shlex.quote, command))}); "
+        script += 'exec "${cmd[@]}"'
+
+        return script
+
+    @staticmethod
+    def make_kill_script(pidfile):
+        script = ""
+        script += f"pid=$(cat {pidfile}); "
+        script += "if ps -p $pid >/dev/null; then "
+        script += "    kill $pid; "
+        script += "    echo 1; "
+        script += "else "
+        script += "    echo 0; "
+        script += "fi; "
+        script += f"rm {pidfile}"
 
         return script
 
@@ -309,7 +305,7 @@ def launch_ring(parser, hosts, args, command):
     _launch_with_io(
         RemoteProcess,
         [
-            ((rank, h.ssh_hostname, cwd, files, env, command), {})
+            ((rank, h.ssh_hostname, args.python, cwd, files, env, command), {})
             for rank, h in enumerate(hosts)
         ],
         args.verbose,
@@ -341,6 +337,7 @@ def launch_nccl(parser, hosts, args, command):
                 (
                     rank,
                     h.ssh_hostname,
+                    args.python,
                     cwd,
                     {},
                     env + [f"CUDA_VISIBLE_DEVICES={rank % args.repeat_hosts}"],
@@ -374,7 +371,7 @@ def launch_jaccl(parser, hosts, args, command):
     _launch_with_io(
         RemoteProcess,
         [
-            ((rank, h.ssh_hostname, cwd, files, env, command), {})
+            ((rank, h.ssh_hostname, args.python, cwd, files, env, command), {})
             for rank, h in enumerate(hosts)
         ],
         args.verbose,
@@ -503,11 +500,20 @@ def main():
         default=12345,
         help="The port to use for the NCCL communication (only for nccl backend)",
     )
+    parser.add_argument(
+        "--no-verify-script",
+        action="store_false",
+        dest="verify_script",
+        help="Do not verify that the script exists",
+    )
+    parser.add_argument(
+        "--python", default=sys.executable, help="Use this python on the remote hosts"
+    )
 
     args, rest = parser.parse_known_args()
 
     if args.print_python:
-        print(sys.executable)
+        print(args.python)
         return
 
     if len(rest) == 0:
@@ -523,10 +529,10 @@ def main():
 
     # Check if the script is a file and convert it to a full path
     if (script := Path(rest[0])).exists() and script.is_file():
-        rest[0:1] = [sys.executable, str(script.resolve())]
+        rest[0:1] = [args.python, str(script.resolve())]
     elif (command := shutil.which(rest[0])) is not None:
         rest[0] = command
-    else:
+    elif args.verify_script:
         raise ValueError(f"Invalid script or command {rest[0]}")
 
     # Launch

setup.py

@@ -266,7 +266,7 @@ if __name__ == "__main__":
     entry_points = {
         "console_scripts": [
             "mlx.launch = mlx._distributed_utils.launch:main",
-            # "mlx.distributed_config = mlx.distributed_run:distributed_config",
+            "mlx.distributed_config = mlx._distributed_utils.config:main",
         ]
     }
     install_requires = []