The chrome hang data on bug 859558 shows a significant number of hangs within RunLoader calls. For some reason I thought we already had an explicit time limit to prevent this but apparently not. The gfxPlatformFontList::RunLoader method is called on a timer and loads the data for a pref-specified number of font families. The pref can be tweaked but I think we should explicitly limit each pass to prevent hangs.

Limit the time spent within one pass of RunLoader to 500ms.

Comment on attachment 8343444 [details] [diff] [review] patch, add time limit to RunLoader Review of attachment 8343444 [details] [diff] [review]: ----------------------------------------------------------------- ::: gfx/thebes/gfxPlatformFontList.cpp @@ +689,5 @@ > mStartIndex = 0; > mNumFamilies = mFontFamiliesToLoad.Length(); > } > > +#define FONT_LOADER_MAX_TIMESLICE 500 // max time for one pass through RunLoader = 500ms How about lowering this to 100ms?

(In reply to Robert O'Callahan (:roc) (Mozilla Corporation) from comment #2) > > +#define FONT_LOADER_MAX_TIMESLICE 500 // max time for one pass through RunLoader = 500ms > > How about lowering this to 100ms? Sure.

Pushed to inbound: https://hg.mozilla.org/integration/mozilla-inbound/rev/dba508605c1b

Please re-add "verifyme" if you want QA to test the fix for this bug (details on how to reproduce it and the used tools would also be necessary in this case).