Bug 129074 – [UI-Side Compositing] 6% of main thread time spent copying LayerProperties when adding to hash table

• Component: New Bugs
• Status: RESOLVED FIXED

[Simon Fraser (smfr)]

[UI-Side Compositing] 6% of main thread time spent copying LayerProperties when adding to hash table

[Simon Fraser (smfr)]

<rdar://problem/15741031>

[Simon Fraser (smfr)]

Created attachment 224691 [details]
Patch

[Tim Horton]

Comment on attachment 224691 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=224691&action=review

> Source/WebKit2/Shared/mac/RemoteLayerTreeTransaction.mm:214
>      if (changedProperties & BackingStoreChanged) {
> -        encoder << backingStore.hasFrontBuffer();
> -        if (backingStore.hasFrontBuffer())
> -            encoder << backingStore;
> +        encoder << backingStore->hasFrontBuffer();
> +        if (backingStore->hasFrontBuffer())
> +            encoder << *backingStore;
>      }

What if BackingStoreChanged because it went away?? I guess we'll still have one, it'll just be one that doesn't paint.

[Simon Fraser (smfr)]

https://trac.webkit.org/r164405

[Ryosuke Niwa]

Looks like this was ~1.5% performance improvement on DoYouEvenBench:
https://perf.webkit.org/#mode=charts&chartList=%5B%5B%22mac-mavericks%22%2C%22DoYouEvenBench%2FFull%3ATime%3ATotal%22%5D%5D

[Tim Horton]

(In reply to comment #5)
> Looks like this was ~1.5% performance improvement on DoYouEvenBench:
> https://perf.webkit.org/#mode=charts&chartList=%5B%5B%22mac-mavericks%22%2C%22DoYouEvenBench%2FFull%3ATime%3ATotal%22%5D%5D

That would be a bit concerning, as this code isn't used at all on Mac at the moment.

[Ryosuke Niwa]

(In reply to comment #6)
> (In reply to comment #5)
> > Looks like this was ~1.5% performance improvement on DoYouEvenBench:
> > https://perf.webkit.org/#mode=charts&chartList=%5B%5B%22mac-mavericks%22%2C%22DoYouEvenBench%2FFull%3ATime%3ATotal%22%5D%5D
> 
> That would be a bit concerning, as this code isn't used at all on Mac at the moment.

Okay. It's probably http://trac.webkit.org/changeset/164401 then.