{"action":"opened","issue":{"url":"https://api.github.com/repos/gunrock/gunrock/issues/65","labels_url":"https://api.github.com/repos/gunrock/gunrock/issues/65/labels{/name}","comments_url":"https://api.github.com/repos/gunrock/gunrock/issues/65/comments","events_url":"https://api.github.com/repos/gunrock/gunrock/issues/65/events","html_url":"https://github.com/gunrock/gunrock/issues/65","id":117370243,"number":65,"title":"Generate multiple bfs trees on one single device transfer","user":{"login":"ranjanan","id":9101377,"avatar_url":"https://avatars.githubusercontent.com/u/9101377?v=3","gravatar_id":"","url":"https://api.github.com/users/ranjanan","html_url":"https://github.com/ranjanan","followers_url":"https://api.github.com/users/ranjanan/followers","following_url":"https://api.github.com/users/ranjanan/following{/other_user}","gists_url":"https://api.github.com/users/ranjanan/gists{/gist_id}","starred_url":"https://api.github.com/users/ranjanan/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ranjanan/subscriptions","organizations_url":"https://api.github.com/users/ranjanan/orgs","repos_url":"https://api.github.com/users/ranjanan/repos","events_url":"https://api.github.com/users/ranjanan/events{/privacy}","received_events_url":"https://api.github.com/users/ranjanan/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-11-17T14:52:42Z","updated_at":"2015-11-17T14:52:42Z","closed_at":null,"body":"Hi.\r\nI was working on an implementation of the Graph500 benchmark in Julia (www.graph500.org). I was using Gunrock to generate the bfs trees. The way Julia interacts with Gunrock is through a `ccall`, which essentially calls the function `void bfs()` through `libgunrock.so` by passing the appropriate arrays, as well as `bfs_label`, and getting the tree in `bfs_label`. Everytime I make this `ccall`, there is host to device transfer as well as a device to host transfer for `bfs_label`. I want to minimize this latency. \r\n\r\nIs there a way for the graph to stay in device memory while I perform a bunch of bfs calls? Finally, it can return a 2D array or another appropriate data structure. "}}