Request for review (L): 7071653: JSR 292: call site change notification should be pushed not pulled

Christian Thalinger christian.thalinger at oracle.com
Fri Aug 5 06:32:14 PDT 2011


http://cr.openjdk.java.net/~twisti/7071653

7071653: JSR 292: call site change notification should be pushed not pulled
Reviewed-by:

Currently every speculatively inlined method handle call site has a
guard that compares the current target of the CallSite object to the
inlined one.  This per-invocation overhead can be removed if the
notification is changed from pulled to pushed (i.e. deoptimization).

I had to change the logic in TemplateTable::patch_bytecode to skip
bytecode quickening for putfield instructions when the put_code
written to the constant pool cache is zero.  This is required so that
every execution of a putfield to CallSite.target calls out to
InterpreterRuntime::resolve_get_put to do the deoptimization of
depending compiled methods.

I also had to change the dependency machinery to understand other
dependencies than class hierarchy ones.  DepChange got the super-type
of two new dependencies, KlassDepChange and CallSiteDepChange.

Tested with JRuby tests and benchmarks, hand-written testcases, JDK
tests and vm.mlvm tests.

Here is the speedup for the JRuby fib benchmark (first is JDK 7 b147,
second with 7071653).  Since the CallSite targets don't change during
the runtime of this benchmark we can see the performance benefit of
eliminating the guard:

$ jruby --server bench/bench_fib_recursive.rb 5 35
  0.883000   0.000000   0.883000 (  0.854000)
  0.715000   0.000000   0.715000 (  0.715000)
  0.712000   0.000000   0.712000 (  0.712000)
  0.713000   0.000000   0.713000 (  0.713000)
  0.713000   0.000000   0.713000 (  0.712000)

$ jruby --server bench/bench_fib_recursive.rb 5 35
  0.772000   0.000000   0.772000 (  0.742000)
  0.624000   0.000000   0.624000 (  0.624000)
  0.621000   0.000000   0.621000 (  0.621000)
  0.622000   0.000000   0.622000 (  0.622000)
  0.622000   0.000000   0.622000 (  0.621000)



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