I understand what you are trying to say specifically, I'll be using Nvidia P4 in us-west2-b zone which is available in that zone according to refrence you gave. But while creating instance I get an error saying "Quota 'GPU_ALL_REGIONS' exceeded. Limit: 0.0 globally. Now to increase quota I tried requesting 5-6 times but it got rejected. Then I contacted support team they asked me to contact sales team, then sales team said they can't do anything about it you should contact our partners or billing team. i tried both partner told since you are already having a project you should contact either billing or sales team, then I tried to contact billing team they told this thing is handled by quota increase team and you should mail at
gc-...@google.com, I've already mailed to them on 30-Jan-2019 but I've not received any reply from them yet.
Now what should I do, its been more than 7 days since I started requesting for GPU increase but I've not received any solution till today by any of google cloud team.