Bug 77012 – Screen freezing for short time while scrolling.

• Component: WebCore Misc.
• Status: RESOLVED WONTFIX

[JungJik Lee]

I found a short time screen freezing while scrolling in GTK and EFL port.
And it was because of the FontCachePurgePreventer.
When the screen is updated, almost every time the browser calls FontCachePurgePreventer.
FontCachePurgePreventer tries to purge the inactive fallback fonts.
It's ok in pages written in alphabet (because it is under font cache limits),
But it becomes overhead in pages written in CJK or none-alphabet.
Actually it takes quite significant time to look inactive fonts up in hash table.
So I simply suggest that FontCachePurgePreventer remains only in (FrameView::reset function).
I will file a patch soon. Any advice will be welcomed.

[JungJik Lee]

Created attachment 126677 [details]
proposal patch

[Michael Saboff]

Comment on attachment 126677 [details]
proposal patch

This timer is in the wrong direction.  If you think you need more inactive fonts, I suggest that you add platform specific values for cMaxInactiveFontData and cTargetInactiveFontData in WebCore/platform/graphics/FontCache.cpp near lines 255-261.  Adopting the CHROMIUM values may be sufficient.

[JungJik Lee]

(In reply to comment #2)
> (From update of attachment 126677 [details])
> This timer is in the wrong direction.  If you think you need more inactive fonts, I suggest that you add platform specific values for cMaxInactiveFontData and cTargetInactiveFontData in WebCore/platform/graphics/FontCache.cpp near lines 255-261.  Adopting the CHROMIUM values may be sufficient.

I've tested with CHROMIUM values, it occurs less then before. However it still show the similar symptom. So I am investigating freetype font on EFL/GTK.
It happens in these site, http://www.sina.com.cn or http://www.daum.net.
Anyway Thank you for attention.