retain undefined tensors in backward pass #41490
Closed
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
albanD
reviewed
Jul 15, 2020
heitorschueroff
requested review from
apaszke,
ebetica,
goldsborough and
yf225
as code owners
💊 CI failures summary and remediationsAs of commit ef17e8a (more details on the Dr. CI page): 💚 💚 Looks good so far! There are no failures yet. 💚 💚 This comment was automatically generated by Dr. CI (expand for details).Follow this link to opt-out of these comments for your Pull Requests.Please report bugs/suggestions on the GitHub issue tracker or post in the (internal) Dr. CI Users group. This comment has been revised 8 times. |
albanD
approved these changes
Jul 15, 2020
Collaborator
albanD
left a comment
albanD
left a comment
There was a problem hiding this comment.
LGTM just small details about the c++ test.
For the BC note I would say will now see it potentially being propagated as it might not depending on the other Nodes.
Contributor
facebook-github-bot
left a comment
facebook-github-bot
left a comment
There was a problem hiding this comment.
@heitorschueroff has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.
Contributor
|
@heitorschueroff merged this pull request in cf811d2. |
facebook-github-bot
pushed a commit
that referenced
this pull request
Aug 11, 2020
Summary: Added a new option in AutogradContext to tell autograd to not materialize output grad tensors, that is, don't expand undefined/None tensors into tensors full of zeros before passing them as input to the backward function. This PR is the second part that closes #41359. The first PR is #41490. Pull Request resolved: #41821 Reviewed By: albanD Differential Revision: D22693163 Pulled By: heitorschueroff fbshipit-source-id: a8d060405a17ab1280a8506a06a2bbd85cb86461
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
5 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Leave undefined tensors / None returned from custom backward functions as undefined/None instead of creating a tensor full of zeros. This change improves performance in some cases.
This is BC-Breaking: Custom backward functions that return None will now see it potentially being propagated all the way up to AccumulateGrad nodes. Potential impact is that .grad field of leaf tensors as well as the result of autograd.grad may be undefined/None where it used to be a tensor full of zeros. Also, autograd.grad may raise an error, if so, consider using allow_unused=True (see doc) if it applies to your case.