### What would you like to be added?

Creating large amount of pods that all use the same image causes the kubelet to start pull per each pod, when parallel pull is enabled. This causes the reigstry QPS to be used, slowing down other pods with other images and also wastes the bandwidth for downloading the same images multiple times.

If same image is being already downloaded in parallel, other pods should just wait for it, not starting new download and not using up registry QPS. 

### Why is this needed?

We have use case where we start large number (500+) pods at the same time where many pods gets scheduled on single node (100+), and most pods have same init container with the same image (given the image on the container is provided with full SHA digest).

This causes lot of bandwidth on the node to be used during the startup of those pods, and also some pods are delayed due to `ImagePullBackoff` caused by `pull QPS exceeded`.
Parallel image pull should pull unique images only once
This is a GitHub Issue
repo:kubernetes
owner:kubernetes
Title : Parallel image pull should pull unique images only once
Issue date:

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### What would you like to be added?

Creating large amount of pods that all use the same image causes the kubelet to start pull per each pod, when parallel pull is enabled. This causes the reigstry QPS to be used, slowing down other pods with other images and also wastes the bandwidth for downloading the same images multiple times.

If same image is being already downloaded in parallel, other pods should just wait for it, not starting new download and not using up registry QPS. 

### Why is this needed?

We have use case where we start large number (500+) pods at the same time where many pods gets scheduled on single node (100+), and most pods have same init container with the same image (given the image on the container is provided with full SHA digest).

This causes lot of bandwidth on the node to be used during the startup of those pods, and also some pods are delayed due to `ImagePullBackoff` caused by `pull QPS exceeded`.
--- end body ---
