ComfyUI/comfy/multigpu.py

108 lines
4.4 KiB
Python

from __future__ import annotations
import torch
from collections import namedtuple
from typing import TYPE_CHECKING
if TYPE_CHECKING:
from comfy.model_patcher import ModelPatcher
class GPUOptions:
def __init__(self, device_index: int, relative_speed: float):
self.device_index = device_index
self.relative_speed = relative_speed
def clone(self):
return GPUOptions(self.device_index, self.relative_speed)
def create_dict(self):
return {
"relative_speed": self.relative_speed
}
class GPUOptionsGroup:
def __init__(self):
self.options: dict[int, GPUOptions] = {}
def add(self, info: GPUOptions):
self.options[info.device_index] = info
def clone(self):
c = GPUOptionsGroup()
for opt in self.options.values():
c.add(opt)
return c
def register(self, model: ModelPatcher):
opts_dict = {}
# get devices that are valid for this model
devices: list[torch.device] = [model.load_device]
for extra_model in model.get_additional_models_with_key("multigpu"):
extra_model: ModelPatcher
devices.append(extra_model.load_device)
# create dictionary with actual device mapped to its GPUOptions
device_opts_list: list[GPUOptions] = []
for device in devices:
device_opts = self.options.get(device.index, GPUOptions(device_index=device.index, relative_speed=1.0))
opts_dict[device] = device_opts.create_dict()
device_opts_list.append(device_opts)
# make relative_speed relative to 1.0
min_speed = min([x.relative_speed for x in device_opts_list])
for value in opts_dict.values():
value['relative_speed'] /= min_speed
model.model_options['multigpu_options'] = opts_dict
LoadBalance = namedtuple('LoadBalance', ['work_per_device', 'idle_time'])
def load_balance_devices(model_options: dict[str], total_work: int, return_idle_time=False, work_normalized: int=None):
'Optimize work assigned to different devices, accounting for their relative speeds and splittable work.'
opts_dict = model_options['multigpu_options']
devices = list(model_options['multigpu_clones'].keys())
speed_per_device = []
work_per_device = []
# get sum of each device's relative_speed
total_speed = 0.0
for opts in opts_dict.values():
total_speed += opts['relative_speed']
# get relative work for each device;
# obtained by w = (W*r)/R
for device in devices:
relative_speed = opts_dict[device]['relative_speed']
relative_work = (total_work*relative_speed) / total_speed
speed_per_device.append(relative_speed)
work_per_device.append(relative_work)
# relative work must be expressed in whole numbers, but likely is a decimal;
# perform rounding while maintaining total sum equal to total work (sum of relative works)
work_per_device = round_preserved(work_per_device)
dict_work_per_device = {}
for device, relative_work in zip(devices, work_per_device):
dict_work_per_device[device] = relative_work
if not return_idle_time:
return LoadBalance(dict_work_per_device, None)
# divide relative work by relative speed to get estimated completion time of said work by each device;
# time here is relative and does not correspond to real-world units
completion_time = [w/r for w,r in zip(work_per_device, speed_per_device)]
# calculate relative time spent by the devices waiting on each other after their work is completed
idle_time = abs(min(completion_time) - max(completion_time))
if work_normalized:
idle_time *= (work_normalized/total_work)
return LoadBalance(dict_work_per_device, idle_time)
def round_preserved(values: list[float]):
'Round all values in a list, preserving the combined sum of values.'
# get floor of values; casting to int does it too
floored = [int(x) for x in values]
total_floored = sum(floored)
# get remainder to distribute
remainder = round(sum(values)) - total_floored
# pair values with fractional portions
fractional = [(i, x-floored[i]) for i, x in enumerate(values)]
# sort by fractional part in descending order
fractional.sort(key=lambda x: x[1], reverse=True)
# distribute the remainder
for i in range(remainder):
index = fractional[i][0]
floored[index] += 1
return floored