Bug 133876 – REGRESSION(r169703): Memory usage (JSHeap) on all performance tests got ~50% worse

• Status: NEW
• Component: JavaScriptCore

[Carlos Alberto Lopez Perez]

Some of the revisions between [r169699-169710] made a significant performance regression on Animation/balls:JSHeap

Mac-MountainLion: 33.98% worse
Mac-Mavericks:    14.18% worse
EFL:               9.52% worse
GTK:              56.66% worse



WebKit: http://trac.webkit.org/log/?rev=169710&stop_rev=169699&verbose=on


The graphs are here: https://perf.webkit.org/#mode=charts&chartList=[[%22efl%22%2C%22Animation%2Fballs%3AJSHeap%22]%2C[%22gtk%22%2C%22Animation%2Fballs%3AJSHeap%22]%2C[%22mac-lion%22%2C%22Animation%2Fballs%3AJSHeap%22]%2C[%22mac-mavericks%22%2C%22Animation%2Fballs%3AJSHeap%22]%2C[%22mac-mountainlion%22%2C%22Animation%2Fballs%3AJSHeap%22]]

[Carlos Alberto Lopez Perez]

(In reply to comment #0)
> Some of the revisions between [r169699-169710] made a significant performance regression on Animation/balls:JSHeap
> 
> Mac-MountainLion: 33.98% worse
> Mac-Mavericks:    14.18% worse
> EFL:               9.52% worse
> GTK:              56.66% worse
> 
> 
> 
> WebKit: http://trac.webkit.org/log/?rev=169710&stop_rev=169699&verbose=on
> 
> 
> The graphs are here: https://perf.webkit.org/#mode=charts&chartList=[[%22efl%22%2C%22Animation%2Fballs%3AJSHeap%22]%2C[%22gtk%22%2C%22Animation%2Fballs%3AJSHeap%22]%2C[%22mac-lion%22%2C%22Animation%2Fballs%3AJSHeap%22]%2C[%22mac-mavericks%22%2C%22Animation%2Fballs%3AJSHeap%22]%2C[%22mac-mountainlion%22%2C%22Animation%2Fballs%3AJSHeap%22]]

Let's see if this link works: https://perf.webkit.org/#mode=charts&chartList=%5B%5B%22efl%22%2C%22Animation%2Fballs%3AJSHeap%22%5D%2C%5B%22gtk%22%2C%22Animation%2Fballs%3AJSHeap%22%5D%2C%5B%22mac-lion%22%2C%22Animation%2Fballs%3AJSHeap%22%5D%2C%5B%22mac-mavericks%22%2C%22Animation%2Fballs%3AJSHeap%22%5D%2C%5B%22mac-mountainlion%22%2C%22Animation%2Fballs%3AJSHeap%22%5D%5D

Otherwise select: "Animation" / "balls:JSHeap" / "All platforms" and click on "Add chart"

[Carlos Alberto Lopez Perez]

There are more tests affected, for example


Bindings/append-child:JSHeap https://perf.webkit.org/#mode=charts&chartList=%5B%5B%22efl%22%2C%22Bindings%2Fappend-child%3AJSHeap%22%5D%2C%5B%22gtk%22%2C%22Bindings%2Fappend-child%3AJSHeap%22%5D%2C%5B%22mac-lion%22%2C%22Bindings%2Fappend-child%3AJSHeap%22%5D%2C%5B%22mac-mavericks%22%2C%22Bindings%2Fappend-child%3AJSHeap%22%5D%2C%5B%22mac-mountainlion%22%2C%22Bindings%2Fappend-child%3AJSHeap%22%5D%5D


Bindings/create-element:JSHeap https://perf.webkit.org/#mode=charts&chartList=%5B%5B%22efl%22%2C%22Bindings%2Fcreate-element%3AJSHeap%22%5D%2C%5B%22gtk%22%2C%22Bindings%2Fcreate-element%3AJSHeap%22%5D%2C%5B%22mac-lion%22%2C%22Bindings%2Fcreate-element%3AJSHeap%22%5D%2C%5B%22mac-mavericks%22%2C%22Bindings%2Fcreate-element%3AJSHeap%22%5D%2C%5B%22mac-mountainlion%22%2C%22Bindings%2Fcreate-element%3AJSHeap%22%5D%5D


Bindings/document-implementation:JSHeap https://perf.webkit.org/#mode=charts&chartList=%5B%5B%22efl%22%2C%22Bindings%2Fdocument-implementation%3AJSHeap%22%5D%2C%5B%22gtk%22%2C%22Bindings%2Fdocument-implementation%3AJSHeap%22%5D%2C%5B%22mac-lion%22%2C%22Bindings%2Fdocument-implementation%3AJSHeap%22%5D%2C%5B%22mac-mavericks%22%2C%22Bindings%2Fdocument-implementation%3AJSHeap%22%5D%2C%5B%22mac-mountainlion%22%2C%22Bindings%2Fdocument-implementation%3AJSHeap%22%5D%5D


etc...

[Carlos Alberto Lopez Perez]

I have bisected the interval and got r169703 as the revision that caused the regression.

You can check here the bisection I did: http://people.igalia.com/clopez/wk133876/PerformanceTestsResults.html
Click on memory at the top left.

I only tested with one Performance test (Bindings/document-implementation.html) to do it faster, but all the other tests would give the same result related to JSHeap memory usage according to perf.webkit.org

[Geoffrey Garen]

It looks like the absolute size of the regression is 60kB - 100kB. Is that right? If so, I think those high percentages just indicate that the test doesn't use much JS memory -- not that something major has changed.

In a test that does use a lot of JS memory, I would expect the memory impact of <http://trac.webkit.org/changeset/169703> to be much lower, percentage-wise, since one prototype is typically used by many client objects, making prototype memory a small fraction of heap memory.

I think we can accept this delta.

[Andreas Kling]

(In reply to comment #4)
> It looks like the absolute size of the regression is 60kB - 100kB. Is that right? If so, I think those high percentages just indicate that the test doesn't use much JS memory -- not that something major has changed.
> 
> In a test that does use a lot of JS memory, I would expect the memory impact of <http://trac.webkit.org/changeset/169703> to be much lower, percentage-wise, since one prototype is typically used by many client objects, making prototype memory a small fraction of heap memory.
> 
> I think we can accept this delta.

Indeed. There is clearly a space/time tradeoff here, and I think 100kB is well within the acceptable range.