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Bug #18572
openPerformance regression when invoking refined methods
Description
Since Ruby 3.0, defining a refinement for a method slows down its execution even if we do not activate the refinement:
require "benchmark_driver"
source = <<~RUBY
class Hash
def symbolize_keys
transform_keys { |key| key.to_sym rescue key }
end
def refined_symbolize_keys
transform_keys { |key| key.to_sym rescue key }
end
end
module HashRefinements
refine Hash do
def refined_symbolize_keys
raise "never called"
end
end
end
HASH = {foo: 1, bar: 2, baz: 3}
class Foo
def original
end
def refined
end
end
module FooRefinements
refine Foo do
def refined
raise "never called"
end
end
end
FOO = Foo.new
RUBY
Benchmark.driver do |x|
x.prelude %Q{
#{source}
}
x.report "#symbolize_keys original", %{ HASH.symbolize_keys }
x.report "#symbolize_keys refined", %{ HASH.refined_symbolize_keys }
end
Benchmark.driver do |x|
x.prelude %Q{
#{source}
}
x.report "no-op original", %{ FOO.original }
x.report "no-op refined", %{ FOO.refined }
end
The results for Ruby 3.1:
...
Comparison:
#symbolize_keys original: 2372420.1 i/s
#symbolize_keys refined: 1941019.0 i/s - 1.22x slower
...
Comparison:
no-op original: 51790974.2 i/s
no-op refined: 14456518.9 i/s - 3.58x slower
For Ruby 2.6 and 2.7:
Comparison:
#symbolize_keys original: 2278339.7 i/s
#symbolize_keys refined: 2264153.1 i/s - 1.01x slower
...
Comparison:
no-op refined: 64178338.5 i/s
no-op original: 63357980.1 i/s - 1.01x slower
You can find the full code and more results in this gist.
P.S. The problem was originally noticed by @byroot (Jean Boussier), see https://github.com/ruby-i18n/i18n/pull/573
Updated by shugo (Shugo Maeda) 3 months ago
- Assignee set to ko1 (Koichi Sasada)
- Status changed from Open to Assigned
It seems that the performance regression was introduced by https://github.com/ruby/ruby/commit/b9007b6c548f91e88fd3f2ffa23de740431fa969
$ cat test.rb
class Foo
def original
end
def refined
end
end
module FooRefinements
refine Foo do
def refined
raise "never called"
end
end
end
FOO = Foo.new
t = Time.now
100000.times do
FOO.refined
end
if Time.now - t > 0.007
puts "slow"
exit 1
else
puts "fast"
exit 0
end
$ rubyfarm-bisect -g 537a1cd5a97a8c5e93b64851abaab42812506f66 -b 546730b76b41b142240891cd1bbd7df7990d5239 -t
(snip)
b9007b6c548f91e88fd3f2ffa23de740431fa969 is the first bad commit
commit b9007b6c548f91e88fd3f2ffa23de740431fa969
Author: Koichi Sasada <ko1@atdot.net>
Date: Wed Jan 8 16:14:01 2020 +0900
Introduce disposable call-cache.
This patch contains several ideas:
(1) Disposable inline method cache (IMC) for race-free inline method cache
* Making call-cache (CC) as a RVALUE (GC target object) and allocate new
CC on cache miss.
* This technique allows race-free access from parallel processing
elements like RCU.
(2) Introduce per-Class method cache (pCMC)
* Instead of fixed-size global method cache (GMC), pCMC allows flexible
cache size.
* Caching CCs reduces CC allocation and allow sharing CC's fast-path
between same call-info (CI) call-sites.
(3) Invalidate an inline method cache by invalidating corresponding method
entries (MEs)
* Instead of using class serials, we set "invalidated" flag for method
entry itself to represent cache invalidation.
* Compare with using class serials, the impact of method modification
(add/overwrite/delete) is small.
* Updating class serials invalidate all method caches of the class and
sub-classes.
* Proposed approach only invalidate the method cache of only one ME.
See [Feature #16614] for more details.
class.c | 45 +-
common.mk | 1 +
compile.c | 38 +-
debug_counter.h | 92 ++--
eval.c | 2 +-
ext/objspace/objspace.c | 1 +
gc.c | 204 +++++++-
id_table.c | 2 +-
insns.def | 13 +-
internal/class.h | 2 +
internal/imemo.h | 4 +
internal/vm.h | 41 +-
iseq.c | 17 +
method.h | 11 +-
mjit.c | 19 +-
mjit.h | 29 ++
mjit_compile.c | 42 +-
mjit_worker.c | 30 +-
test/-ext-/tracepoint/test_tracepoint.rb | 12 +-
test/ruby/test_gc.rb | 3 +
test/ruby/test_inlinecache.rb | 64 +++
tool/mk_call_iseq_optimized.rb | 2 +-
tool/ruby_vm/views/_mjit_compile_send.erb | 23 +-
tool/ruby_vm/views/mjit_compile.inc.erb | 2 +-
vm.c | 26 +-
vm_callinfo.h | 235 ++++++++-
vm_core.h | 3 +-
vm_dump.c | 4 +-
vm_eval.c | 50 +-
vm_insnhelper.c | 814 ++++++++++++++++--------------
vm_insnhelper.h | 15 +-
vm_method.c | 630 ++++++++++++++---------
32 files changed, 1606 insertions(+), 870 deletions(-)
create mode 100644 test/ruby/test_inlinecache.rb
bisect run success
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