[Core][REP] GPU Memory awareness scheduling - #47
Conversation
Signed-off-by: Jonathan Nitisastro <jonathancn@anyscale.com>
Signed-off-by: Jonathan Nitisastro <jonathancn@anyscale.com>
Signed-off-by: Jonathan Nitisastro <jonathancn@anyscale.com>
Signed-off-by: Jonathan Nitisastro <jonathancn@anyscale.com>
Signed-off-by: Jiajun Yao <jeromeyjj@gmail.com>
| ```python | ||
| # Request a fractional GPU with specified gpu_memory in bytes. | ||
| # Mutually exclusive with num_gpus. | ||
| @ray.remote(gpu_memory=1024 * 1024 * 1024) # 1 mb request |
There was a problem hiding this comment.
Can we support string-based syntactic sugar? Feels more pythonic that way (i.e., gpu_memory="3gb")
There was a problem hiding this comment.
for now we just follow how memory is defined. I think the pythonic support can be done separately which covers both gpu_memory and memory changes
| ```python | ||
| pg = placement_group([{"gpu_memory": 1024 * 1024, "CPU": 1}, {"GPU": 1}]) | ||
| ``` | ||
|
|
There was a problem hiding this comment.
I think we need the observability section here as this complicates the observability semantics.
- how is it displayed in ray status?
- for ray status, it should potentially display sth like gpu_memory: 4 gpus (A10) * 3gb?
- In ray status, if a task is scheduled with gpu_memory, both gpu & gpu memory values are subtracted?
- How is it displayed in resource_requirement in ray list tasks? Is it translated into num_gpus? Or it only includes gpu_memory? Or both?
There was a problem hiding this comment.
in ray list nodes, it will be GPU (resources left) * gpu_memory_per_gpu which is the constant stored in node label. ray status, ray list task and ray.available_resources currently didn't show GPU memory but if we added one, it will be the same as ray list nodes.
and yes, basically both gpu and gpu_memory values are subtracted to show the remaining
|
|
||
| # Requesting 30GB of GPU memory from a A10 GPU with 24GB of memory. | ||
| # Task won't be able to be scheduled. | ||
| @ray.remote(gpu_memory=30 * 1024 * 1024 * 1024 * 1024, accelerator_type="NVIDIA_TESLA_A10G") |
There was a problem hiding this comment.
If you have 40GB gpu
and schedule 1 task with 20GB
and schedule another with with num_gpus=1, would it fail to schedule?
There was a problem hiding this comment.
yes, the second one will fail since the GPU remaining after scheduler 20GB task will be 0.5
|
|
||
| ```python | ||
| # Request a fractional GPU both num_gpus and gpu_memory is not allowed | ||
| @ray.remote(gpu_memory=1024 * 1024 * 1024, num_gpus=0.5) # raise ValueError exception |
There was a problem hiding this comment.
is it possible to express 2 GPUs using gpu_memory? Or is it not allowed?
There was a problem hiding this comment.
can you specify this in REP?
There was a problem hiding this comment.
it's not allowed, since only either one of num_gpus or gpu_memory (1 gpu per request) can be specified in request
There was a problem hiding this comment.
Could they both be allowed? If both num_gpus and gpu_memory are specified, then it would require that much memory on that many GPUs. num_gpus would default to 1, so not specifying it would get the behavior described above. It could be an error condition to specify a fractional value for num_gpus if also specifying gpu_memory. Thoughts?
5 participants
The GPU memory scheduling prototype:
ray-project/ray#41147