Bug 40042 – [Qt] Hovering the mouse cursor on a Flash content causes very high CPU load

• Status: RESOLVED
• Resolution: INVALID
• Component: WebKit Qt

[Ryuichi KUBUKI]

The affected environment is Flash 10.1.51.45 + Qt 4.7 Beta + Windows XP SP3 (Japanese).

[How to Reproduce]

1. Build and run browser.exe in the Qt demos
2. Extract the attached zip
3. Open .html with browser.exe
4. Hover the mouse cursor around the left side of the Flash content

[Actual Result]

CPU usage spikes to 50% (full load on 1 of 2 CPU cores)

[Expected Result]

A lot less CPU load



On Safari 4.0.5 in the same PC, it's under 10% load.

[Ryuichi KUBUKI]

Created attachment 57622 [details]
testcase

[Balazs Kelemen]

I tried it on linux with the QtTestBrowser of WebKit trunk with qt-4.6.2,  flash 10.0.22.87. The cpu load was normal (between about 10-35%).
I would ask you to run your test case against the trunk.

[Ryuichi KUBUKI]

(In reply to comment #2)
> I tried it on linux with the QtTestBrowser of WebKit trunk with qt-4.6.2,  flash 10.0.22.87. The cpu load was normal (between about 10-35%).
> I would ask you to run your test case against the trunk.

Running the testcase with WebKit r60645 + Qt 4.6.1 (built with VS2008) on Windows Server 2003 shows the same behavior where CPU load spikes when I move the mouse cursor on the Flash swf.

I guess something is wrong about window message processing on Windows while it's OK on Linux.

[Ryuichi KUBUKI]

Still happening on the QtTestBrowser.exe with WebKit r61615 + Qt 4.6.3 (built with VS2008) + Flash 10.1.53.64 + Windows XP SP3.

Can someone on Windows confirm this? A test case is available.

[Diego Gonzalez]

Please someone try to confirm it on Windows