[jira] [Commented] (SYSTEMML-1545) Incorrect leftindexing memory estimate w/ empty input in loops

["Matthias Boehm (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/SYSTEMML-1545?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15974096#comment-15974096 ] 

Matthias Boehm commented on SYSTEMML-1545:
------------------------------------------

cc [~acs_s]

> Incorrect leftindexing memory estimate w/ empty input in loops
> --------------------------------------------------------------
>
>                 Key: SYSTEMML-1545
>                 URL: https://issues.apache.org/jira/browse/SYSTEMML-1545
>             Project: SystemML
>          Issue Type: Bug
>            Reporter: Matthias Boehm
>            Priority: Blocker
>
> The current memory estimate of leftindexing operations is incorrect (in terms of a dangerous underestimation that leads to OOMs) for empty input matrices in loops. For example, consider the following script
> {code}
> R = matrix(0, N, r^2);
> parfor(i in 1:nrow(X)) {
>   Xi = X[i,]
>   R[i,] = matrix(t(Xi)%*%Xi, 1, ncol(X)^2)
> }
> {code}
> In this scenario, the memory estimate of R[i,] is mistakenly set to a single row, which is only valid during dynamic recompilation with constant indexing range quantifiers.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)