uniq -c | sort -nr 14894134 cache eviction: ActiveModel::AttributeSet#fetch_value is called from activerecord-22.214.171.124/lib/active_record/attribute_methods/read.rb:39 4139225 cache eviction: Concurrent::Map# is called from concurrent-ruby-1.1.6/lib/concurrent-ruby/concurrent/map.rb:133 3912799 cache eviction: Topic#_read_attribute is called from activerecord-126.96.36.199/lib/active_record/attribute_methods/read.rb:17 3329993 cache eviction: User#_read_attribute is called from activerecord-188.8.131.52/lib/active_record/attribute_methods/primary_key.rb:19 1739540 cache eviction: User#_read_attribute is called from activerecord-184.108.40.206/lib/active_record/attribute_methods/read.rb:17 1722911 cache eviction: ActionView::OutputBuffer#<< is called from actionview-220.127.116.11/lib/action_view/buffers.rb:29 1670132 cache eviction: Module#site_id_lookup is called from message_bus-3.3.1/lib/message_bus/distributed_cache.rb:154 1285677 cache eviction: ActiveRecord::Type::HashLookupTypeMap#fetch is called from activerecord-18.104.22.168/lib/active_record/connection_adapters/postgresql_adapte 1158602 cache eviction: Post#_read_attribute is called from activerecord-22.214.171.124/lib/active_record/attribute_methods/read.rb:17 1111963 cache eviction: ActionDispatch::Journey::Visitors::Each#visit is called from actionpack-126.96.36.199/lib/action_dispatch/journey/visitors.rb:162 1079094 cache eviction: NilClass#blank? is called from activesupport-188.8.131.52/lib/active_support/core_ext/object/blank.rb:26 973103 cache eviction: ActiveRecord::Reflection::ThroughReflection#options is called from activerecord-184.108.40.206/lib/active_record/reflection.rb:806 973103 cache eviction: ActiveRecord::Reflection::ThroughReflection#active_record is called from activerecord-220.127.116.11/lib/active_record/reflection.rb:806 940974 cache eviction: Arel::Visitors::PostgreSQL#visit_Arel_Attributes_Attribute is called from activerecord-18.104.22.168/lib/arel/visitors/visitor.rb:30 740641 cache eviction: Post#_read_attribute is called from activerecord-22.214.171.124/lib/active_record/associations/belongs_to_association.rb:119 686061 cache eviction: Topic#_read_attribute is called from activerecord-126.96.36.199/lib/active_record/attribute_methods/primary_key.rb:19 675719 cache eviction: ActiveRecord::ConnectionAdapters::PostgreSQLAdapter#_quote is called from activerecord-188.8.131.52/lib/active_record/connection_adapters/po 610875 cache eviction: User#respond_to? is called from activerecord-184.108.40.206/lib/active_record/attribute_methods.rb:212 609323 cache eviction: Class#type_for_attribute is called from activerecord-220.127.116.11/lib/active_record/table_metadata.rb:33 604621 cache eviction: Topic#_read_attribute is called from activerecord-18.104.22.168/lib/active_record/attribute_methods/read.rb:32 555429 cache eviction: User#read_attribute is called from activerecord-22.214.171.124/lib/active_record/attribute_methods.rb:323 555429 cache eviction: User#_read_attribute is called from activerecord-126.96.36.199/lib/active_record/attribute_methods/read.rb:32 544500 cache eviction: Arel::Visitors::PostgreSQL#visit_Arel_Nodes_BindParam is called from activerecord-188.8.131.52/lib/arel/visitors/visitor.rb:30 541906 cache eviction: ActiveModel::Type::Integer#cast is called from activemodel-184.108.40.206/lib/active_model/type/helpers/numeric.rb:19
Populates its call cache with `User#_read_attribute` 2. `Post#read_attribute` is called. 1. Runs `AR::AM::Read#read_attribute` 2. Evicts previous `User#_read_attribute` entry and populates its own `Post#_read_attribute` 3. `User#read_attribute` is called. 1. Runs `AR::AM::Read#read_attribute` 2. Evicts previous `Post#_read_attribute` entry and populates its own `User#_read_attribute`
consider class hierarchy? • NG; there are refinements. Method resolution can vary from call site to call site. Class hierarchy is not suitable for the needs. • Also, it is dead slow to scan inheritance tree every time a method is called. • Remember (class, method) tuple for each and every call site • → Way to go.
from (class, symbol) tuple to a method body. We modified it to stores multiple classes, which share the identical method name for identical method body. • Ko1 told me that this is a variant of polymorphic inline caching. • Hölzle et al., “Optimizing dynamically-typed object-oriented languages with polymorphic inline caches” in Proceedings of ECOOP ’91. LNCS 512. https://doi.org/10.1007/BFb0057013
by 90.80% → 95.06% • Response time median decreased by 70msec → 69msec • Response time mode decreased by 69msec → 67msec • Profiler no longer considers `vm_call_iseq_setup` one of the hottest path. Specialised functions to show up instead.
only what I described today) was entirely discarded then rewritten by @ko1. • This was for Ractor (then-called Guild) migration. • https://bugs.ruby-lang.org/issues/16614 • This slowed things down a bit, according to him. • Would 2.7 be the fastest lethal ruby implementation we ever made? Watch out for Ruby 3! • It might be possible to re-implement polymorphic inline caches on top of Ractor. But cannot reuse this original design.