906773 - PJS: New "ComputeSliceBounds" function in ParallelArray.js

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[daniele bonetta]

This patch includes an improved version of the "ComputeSliceBounds" function used to split the ParallelArray. The new version assigns tasks to parallel workers more efficiently.

Comment 1

[daniele bonetta]

Attachment: bug-906773-fix.patch

Comment 2

[Sankha Narayan Guria [:sankha]]

Comment on attachment 792309 [details] [diff] [review]
bug-906773-fix.patch

Review of attachment 792309 [details] [diff] [review]:
-----------------------------------------------------------------

Marking Shu for review.

::: js/src/builtin/ParallelArray.js
@@ +56,5 @@
>  function ComputeSliceBounds(numItems, sliceIndex, numSlices) {
>    var sliceWidth = (numItems / numSlices) | 0;
> +  var extraChunks = (numItems % numSlices) | 0;
> +
> +  var startIndex = sliceWidth * sliceIndex + Math.min(extraChunks, sliceIndex);

Math.min should be std_Math_min.

@@ +83,5 @@
> +    ARRAY_PUSH(info, SLICE_INFO(counter, counter + sliceWidth + 1));
> +    counter += sliceWidth + 1;
> +  }
> +  for (; i < numSlices; i++) {
> +    ARRAY_PUSH(info, SLICE_INFO(counter, counter + sliceWidth));    

nit: whitespace at the end.

Comment 3

[Niko Matsakis [:nmatsakis]]

Comment on attachment 792309 [details] [diff] [review]
bug-906773-fix.patch

Review of attachment 792309 [details] [diff] [review]:
-----------------------------------------------------------------

Marking as r+, presuming that sankha93 comments are addressed

Comment 4

[daniele bonetta]

Attachment: bug-906773-fix.patch

Comment 5

[Sankha Narayan Guria [:sankha]]

Attachment: patch with proper commit message

Oh, this wasn't pushed. I updated the commit message and marking checkin-needed.

Comment 6

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/fda5c46503d1

Comment 7

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/fda5c46503d1