742899 - investigate whether caching js in the startup cache is still useful

Status: RESOLVED FIXED

(Core :: XPCOM, defect)

Description

[Nathan Froyd [:froydnj]]

If it's not, then we can just make it go away, and with it problems like bug 741772.

Comment 1

[Joshua Cranmer [:jcranmer]]

Attachment: Testing patch

For various reasons, I ended up testing this patch on try recently. 

ts_paint results:
Platform 	Original    	New 	     	Delta 	Delta %
Windows XP	569.38	±2.36	631.24	±1.72	61.86	10.86%
Windows 7	722.57	±3.9	807.07	±32.86	84.5	11.69%
Mac 10.6	755.18	±9.28	821.06	±51.16	65.88	8.72%
Mac 10.7	862.89	±18	919.78	±13.58	56.89	6.59%
Linux	        715.41	±4.34	787.47	±12.5	72.06	10.07%
Linux 64-bit	654.23	±5.04	723.39	±5.86	69.16	10.57%

Full results are here: <http://perf.snarkfest.net/compare-talos/index.html?oldRevs=60b6d4242bea&newRev=03fc22a5fcdd&submit=true>.

Conclusion: Yes, JS caching still makes a big difference in startup cache.