Bug ID: JDK-8008938 TieredCompilation should be default

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JDK 8	Other
8Fixed	hs25Fixed

For customers migrating from jrockit, not enabling tiered compilation by default leads to a number of regressions:

1) For fusion apps, tiered compliation yields a large benefit (assuming we have adequate code cache). This is because fa are large, and so have a long warm up cycle before everything gets compiled, but also because there ends up being code that never gets compiled because it is called too infrequently.

2) For quick-runing programs using a 64-bit JVM, the early compilation by jrockit enables them to run much faster.

TieredCompilation was disabled because the codecache fills up quickly. The current sweeper doesn't do a good job at cleaning out the codecache which effectively stops compilation when the codecache fills up. Currently if you enable TieredCompilation, the codecache is expanded automatically but the real fix is to fix the sweeper.
15-03-2013
please find the attached Excel sheet (1212stage19+_TieredCompilation-Effect.xls) for above data shared for two comaprison tables on Linux64 and windows-64 platform. (added excel sheet as above data alignment is not proper.) Rachana sakhare rachana.sakhare@oracle.com
07-03-2013
Here is the TC (Tiered Compilation) impact data using DevX (no Memory footprint footprint scenario) on Linux64 platform using 1212 WLS and JDK7u10. In Deployment scenarios we are seeing good gains around 20-26% when TC is enabled.while startup scenario shows improvement around 5-9% Linux64 DevX data 1212stage19+ wo/TC 1212 stage19+ w/TC Diff% Startup Timings Result StdDev(%) Result StdDev(%) Diff% Cold Startup 7.342 3.75 6.964 3.40 5.15 Warm Startup 7.036 1.00 6.405 4.84 8.97 Deployment Timings SJAS2004: Cold Deployment (w/compile) 9.321 4.07 6.875 4.72 26.24 SE2010: Cold Deployment (w/compile) 8.493 4.19 6.567 2.63 22.68 SE2010: Cold Deployment (pre-compiled) 5.674 5.16 4.534 2.55 20.09 Here is the TC (Tiered Compilation) impact data using DevX (no Memory footprint footprint scenario) on Windows-64 platform using 1212 WLS and JDK7u10. Here it did not seem to have much impact to server startup and deployment scenarios Enableing TC Windows64 DevX data 1212 stage19+ wo/TC 1212 stage19+ w/TC Startup Timings Result StdDev(%) Result StdDev. (%) Diff% Cold Startup 8.039 2.50 7.992 2.14 0.58 Warm Startup 7.721 1.68 7.882 3.19 -2.09 Deployment Scenario SJAS2004: Cold Deployment (w/compile) 10.356 3.88 9.414 3.24 9.10 SE2010: Cold Deployment (w/compile) 9.066 5.15 9.398 4.03 -3.66 SE2010: Cold Deployment (pre-compiled) 6.361 5.32 6.139 4.55 3.49 Rachana sakhare rachana.sakhare@oracle.com
07-03-2013
1212stage19+_TieredCompilation-Effect.xls
07-03-2013