def start_ddp_workers()

in denoiser/executor.py [0:0]

• 25 lines of code
• 5 McCabe index (conditional complexity)

def start_ddp_workers(cfg):
    import torch as th
    log = utils.HydraConfig().hydra.job_logging.handlers.file.filename
    rendezvous_file = Path(cfg.rendezvous_file)
    if rendezvous_file.exists():
        rendezvous_file.unlink()

    world_size = th.cuda.device_count()
    if not world_size:
        logger.error(
            "DDP is only available on GPU. Make sure GPUs are properly configured with cuda.")
        sys.exit(1)
    logger.info(f"Starting {world_size} worker processes for DDP.")
    with ChildrenManager() as manager:
        for rank in range(world_size):
            kwargs = {}
            argv = list(sys.argv)
            argv += [f"world_size={world_size}", f"rank={rank}"]
            if rank > 0:
                kwargs['stdin'] = sp.DEVNULL
                kwargs['stdout'] = sp.DEVNULL
                kwargs['stderr'] = sp.DEVNULL
                log += f".{rank}"
                argv.append("hydra.job_logging.handlers.file.filename=" + log)
            manager.add(sp.Popen([sys.executable] + argv, cwd=utils.get_original_cwd(), **kwargs))
    sys.exit(int(manager.failed))